Plant Resources of Tropical Africa 1. Cereals and pulses. Editors: M. Brink G. Belay. Associate editors: J.M.J. de Wet O.T. Edje E.

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1 Plant Resources of Tropical Africa 1 Cereals and pulses Editors: M. Brink G. Belay Associate editors: J.M.J. de Wet O.T. Edje E. Westphal General editors: R.H.M.J. Lemmens L.P.A. Oyen PROTA Foundation / Backhuys Publishers / CTA Wageningen, Netherlands, 2006 r\

2 Correct citation of this publication: Brink, M. & Belay, G. (Editors), Plant Resources of Tropical Africa 1. Cereals and pulses. PROTA Foundation, Wageningen, Netherlands / Backhuys Publishers, Leiden, Netherlands / CTA, Wageningen, Netherlands. 298 pp. Correct citation of articles from this publication: [Author name, initials, Title of article]. In: Brink, M. & Belay, G. (Editors). Plant Resources of Tropical Africa 1. Cereals and pulses. PROTA Foundation, Wageningen, Netherlands / Backhuys Publishers, Leiden, Netherlands / CTA, Wageningen, Netherlands, pp.... ISBN (book only) ISBN (book + CD-Rom) PROTA Foundation, Wageningen, Netherlands, No part of this publication, apart from bibliographic data and brief quotations embodied in critical reviews, may be reproduced, re-recorded or published in any form including print, photocopy, microfilm, electric or electromagnetic record without written permission from the copyright holder: PROTA Foundation, P.O. Box 341, 6700 AH Wageningen, Netherlands. Printed in the Netherlands by Ponsen & Looijen bv, Wageningen. Distributed for the PROTA Foundation by Backhuys Publishers, P.O. Box 321, 2300 AH Leiden, Netherlands (worldwide), and CTA, P.O. Box 380, 6700 AJ Wageningen, Netherlands (ACP countries).

3 Contents Contributors 6 PROTA Board of Trustees and Personnel 9 Introduction 11 Alphabetical treatment of cereals and pulses 15 Cereals and pulses with other primary use 239 Literature 242 Index of scientific plant names 289 Index of vernacular plant names 293 PROTA in short 296 CTA in short 297 Map of Tropical Africa for PROTA 298

4 6 CEREALSAND PULSES Contributors E.G. Achigan Dako, IPGRI West and Central Africa, 08 B.P. 0932, Cotonou, Benin (Digitaria exilis, Macrotyloma geocarpum) S.G. Agong, Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P.O. Box , Nairobi, Kenya (Amaranthus caudatus) R. Akromah, Department of Crop and Soil Sciences, College of Agriculture and Natural Resources, KNUST, Kumasi, Ghana (Vigna unguiculata) D.J. Andrews, Department of Agronomy and Horticulture, University of Nebraska, P.O. Box , Lincoln, NE , United States (Pennisetum glaucum) I.K. Asante, Department of Botany, P.O. Box LG55, University of Ghana, Legon. Accra, Ghana (Vigna unguiculata) G. Assefa, Humboldt University, Berlin, Faculty of Agriculture and Horticulture, Philipstrasse 13, House no. 9, Berlin, Germany / Ethiopian Agricultural Research Organization, Holetta Research Centre, P.O. Box, 2003, Addis Ababa, Ethiopia (Avena sativa) B. Badu-Apraku, UTA Ibadan, c/o Lambourn (UK) Limited, Carolyn House, 26 Dingwall Road, Croydon, CR9 3EE, United Kingdom (Zea mays) T.V. Balole, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana (Sorghum bicolor) J.P. Baudoin, Faculté universitaire des Sciences agronomiques de Gembloux (FUSAGx), Unité de Phytotechnie tropicale et d'horticulture, Passage des Déportés, 2, 5030 Gembloux, Belgium (Phaseolus lunatus) G. Bejiga, Green Focus Ethiopia, P.O. Box 802, Addis Ababa, Ethiopia (Cicer arietinum, Lathyrus sativus, Lens culinaris) G. Belay, Ethiopian Agricultural Research Organization, Debre Zeit Centre, P.O. Box 32, Debre Zeit, Ethiopia (Eragrostis tef, Triticum aestivum, Triticum turgidum, editor) G. Bezançon, Institut de Recherche pour le Développement (IRD), B.P , Niamey, Niger (Oryza glaberrimà) C.H. Bosch, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands (Bauhinia petersiana) M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands (Avena abyssinica, Brachiaria deflexa, Cenchrus biflorus, Cenchrus prieurii, Cordeauxia edulis, Craibia brownii, Crotalaria karagwensis, Crotalaria lachnophora, Digitaria iburua, Echinochloa frumentacea, Echinochloa obtusiflora, Echinochloa stagnina, Eragrostis aethiopica, Eragrostis annulata, Eragrostis nindensis, Eragrostis plana, Limeum obovatum, Macrotyloma uniflorum, Mucuna gigantea, Oryza barthii, Oryza longistaminata, Oryza punctata, Panicum kalaharense, Panicum laetum, Panicum turgidum, Phaseolus coccineus, Secale cereale, Setaria italica, Sporobolus fimbriatus, Sporobolus panicoides, Tylosema fassoglense, Urochloa mosambicensis, Urochloa

5 CONTRIBUTORS 7 trichopus, Vatovaea pseudolablab, Vicia hirsuta, Vigna aconitifolia, Vigna adenantha, Vigna subterranea, editor) S. Ceccarelli, ICARDA, P.O. Box 5466, Aleppo, Syria (Hordeum vulgare) K.E. Dashiell, USDA-ARS Northern Grains Insect Research Laboratory, 2923 Medary Avenue, Brookings SD 57006, United States (Glycine max) J.M.J, de Wet, Department of Crop Sciences, Urbana-Champaign, Turner Hall, 1102 South Goodwin Avenue, Urbana, IL 61801, United States (Eleusine coracana, associate editor) S. Diallo, ISRA / Zone Fleuve, CRA de Saint-Louis, B.P. 240 Sor Saint-Louis, Senegal (Oryza glaberrima) O.T. Edje, Faculty of Agriculture, University of Swaziland, P.O. Luyengo, Luyengo, Swaziland (associate editor) M.A.B. Fakorede, Department of Plant Science, Obafemi Awolowo University, Ile-Ife, Nigeria (Zea mays) K.E. Giller, Plant Production Systems, Department of Plant Sciences, Wageningen University, P.O. Box 430, 6700 AK Wageningen, Netherlands (Glycine max) S. Grando, ICARDA, P.O. Box 5466, Aleppo, Syria (Hordeum vulgare) G.J.H. Grubben, Boeckweijdt Consult, Prins Hendriklaan 24, 1401 AT Bussum, Netherlands (Vigna unguiculata) P.C.M. Jansen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands (Coix lacryma-jobi, Fagopyrum esculentum, Lupinus albus, Vigna aconitifolia, Vigna adenantha, Vigna angularis, Vigna mungo) M. Jarso, Ethiopian Agricultural Research Organization, Holetta Research Center, P.O. Box 2003, Addis Ababa, Ethiopia (Pisum sativum, Vicia faba) R.N. Kaume, P.O. Box , Kitui, Kenya (Panicum miliaceum) G. Keneni, Ethiopian Agricultural Research Organization, Holetta Research Center, P.O. Box 2003, Addis Ababa, Ethiopia (Pisum sativum, Vicia faba) K.A. Kumar, Agriculture Environmental Renewal Canada Inc., 711 Schäfer Road, P.O. Box 186, Delhi, ON N4B 2W9, Canada (Pennisetum glaucum) G.M. Legwaila, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana (Sorghum bicolor) R.H.M.J. Lemmens, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands (general editor) R. Madamba, Crop Breeding Institute, Department of Research & Specialist Services, Box CY 550, Causeway, Harare, Zimbabwe (Vigna unguiculata) H.C.C. Meertens, Pomona 250, 6708 CJ Wageningen, Netherlands (Oryza sativa) C.-M. Messiaen, Résidence La Guirlande, Bat. B3, 75, rue de Fontcarrade, Montpellier, France (Pisum sativum) K.K. Mogotsi, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana (Phaseolus acutifolius, Vigna radiata) B.R. Ntare, ICRISAT, B.P. 320, Bamako, Mali (Arachis hypogaea) Achmad Satiri Nurhaman, Southeast Asian Regional Centre for Tropical Biology (SEAMEO BIOTROP), P.O. Box 17, Bogor, Indonesia (illustrations) L.P.A. Oyen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands (general editor)

6 8 CKREALSAND PULSES - R. Rajerison, CNRE, B.P. 1739, Fiadanana, Antananarivo (101), Madagascar (Vigna umbellata) - G.M. Ramolemana, Department of Crop Science and Production, Botswana College of Agriculture, Private Bag 0027, Gaborone, Botswana (Vigna subterranea) - A.A. Seif, ICIPE, P.O. Box 30772, Nyago Stadium, Nairobi, Kenya (Pisum sativum) - K.P. Sibuga, Department of Crop Science and Production, Sokoine University of Agriculture, P.O. Box 3005, Morogoro, Tanzania (Vigna subterranea) - Iskak Syamsudin, Herbarium Bogoriense, Research Centre for Biology - LIPI, Jalan Ir. H. Juanda 22, Bogor 16122, Indonesia (illustrations) - H. Tefera, Ethiopian Agricultural Research Organization, Debre Zeit Centre, P.O. Box 32, Debre Zeit, Ethiopia (Eragrostis tef) - L.J.G. van der Maesen, Biosystematics Group, Wageningen University, Gen. Foulkesweg 37, 6703 BL Wageningen, Netherlands (Cajanus cajan, Cicer arietinum, Tylosema esculentum) - S.R. Vodouhè, IPGRI West and Central Africa, 08 B.P. 0932, Cotonou, Benin (Digitaria exilis, Macrotyloma geocarpum) - W. Wessel-Brand, Biosystematics Group, Wageningen University, Gen. Foulkesweg 37, 6703 BL Wageningen, Netherlands (illustrations) - E. Westphal, Ritzema Bosweg 13, 6706 BB Wageningen, Netherlands (associate editor) - CS. Wortmann, University of Nebraska Lincoln, IANR, Department of Agronomy and Horticulture, 154 Keim Hall, Lincoln, NE , United States (Phaseolus vulgaris) - S.S. Yadav, Division of Genetics, Indian Agricultural Research Institute, New Delhi , India (Lathyrus sativus) Acknowledgments - S. van Otterloo-Butler, Bowlespark 21, 6701 DR Wageningen, Netherlands (English language correction) - N. Wulijarni-Soetjipto, PROSEA Network Office, P.O. Box 332, Bogor 16122, Indonesia (coordination illustrators)

7 PROTA Board of Trustees and Personnel Board of Trustees J.R. Cobbinah (FORIG, Ghana), chairman M.J. Kropff (WU, Netherlands), vice-chairman H. Andriamialison (PBZT, Madagascar) P.R. Crane (RBGKEW, United Kingdom) D. Garrity (ICRAF, Kenya) L.S. Luboobi (MU, Uganda) Z.L.K. Magombo (NHBGM, Malawi) G. Matheron (AGROPOLIS, France) S. Mbadinga (CENAREST, Gabon) M. Ouédraogo (CNSF, Burkina Faso) E. Sukara (PROSEA, Indonesia) Personnel Regional Office Central Africa, Gabon S. Mbadinga, Programme Leader B. Nziengui, Regional Officer P.M. Nsole Biteghe, Assistant Regional Officer D.N. Omokolo, Contact Person Cameroon M.K.D. Ben-Bala, Contact Person Central African Republic Regional Office East Africa, Uganda J.S. Kaboggoza, Programme Leader R. Bukenya-Ziraba, Regional Officer M. Atim, Assistant Regional Officer A. Tsegaye, Contact Person Ethiopia J. Elia, Contact Person Tanzania Regional Office Indian Ocean Islands, Madagascar S. Rapanarivo, Programme Leader M.E. Rahelivololana, Regional Officer A. Gurib-Fakim, Contact Person Mauritius S. Brillant, Contact Person Réunion Regional Office Southern Africa, Malawi Z.L.K. Magombo, Programme Leader N.G. Nyirenda, Regional Officer V.K. Kawanga, Contact Person Zambia

8 10 CEREALS AND PULSES Regional Office (anglophone) West Africa, Ghana J.R. Cobbinah, Programme Leader S. Britwum, Regional Officer A. Armooh, Assistant Regional Officer O.A. Denton, Contact Person Nigeria Regional Office (francophone) West Africa, Burkina Faso M. Ouédraogo, Programme Leader A. Traoré, Regional Officer V. Millogo, Assistant Regional Officer C. Kouamé, Contact Person Côte d'ivoire F. Assogba-Komlan, Contact Person Benin Country Office France M. Chauvet, Programme Leader W. Rodrigues, Country Officer Country Office United Kingdom S.D. Davis, Programme Leader O. Grace, Country Officer Network Office Africa, Kenya E.A. Omino, Head J. Chege, Database Officer D.J. Borus, Dissemination Officer B.O. Obongoya, Programme Officer M.W. Kamanda, Secretary D. Laur, Office Assistant Network Office Europe, Netherlands J.S. Siemonsma, Head A.D. Bosch-Jonkers, Secretary/Management Assistant R.H.M.J. Lemmens, General Editor L.P.A. Oyen, General Editor E.J. Bertrums, Databank Manager C.H. Bosch, Editor/Dissemination Officer M. Brink, Editor A. de Ruijter, Editor G.H. Schmelzer, Editor/Dissemination Officer

9 11 Introduction Choice of species PROTA 1: 'Cereals and pulses' describes the cultivated and wild species of tropical Africa used as a cereal or pulse. Cereals can be defined as grasses (family Poaceae) of which the grain is used for food; they may be cultivated or the grain is collected from wild plants ('wild cereals'). Three cereals that are not grasses ('pseudo-cereals') have also been included in this volume: Amaranthus caudatus L. (grain amaranth), Fagopyrum esculentum Moench (buckwheat) and Limeum obovatum Vicary. Pulses can be defined as leguminous species (members of the families Papilionaceae, Caesalpiniaceae or Mimosaceae, often considered as one family Leguminosae) producing edible mature seeds. Pulses may also be cultivated or collected from the wild. Some species are only used as a cereal or pulse, but most have several uses. PROTA normally assigns a single primary use and, where relevant, one or more secondary uses to all plant species used in Africa. PROTA 1: 'Cereals and pulses' comprises only accounts of species whose primary use is as a cereal or pulse. The primary use of pigeon pea (Cajanus cajan (L.) Millsp.) is as a pulse, and thus it is treated in PROTA 1, but it has various secondary uses, e.g. the immature seeds and pods are eaten as a vegetable, the seeds and the by-products of dhal production are used as animal feed, the vegetative parts are used as fodder, the stems and branches are used for basketry, thatching, fencing and as fuel, from various plant parts traditional medicines are prepared, and the plants are grown as a shade crop or cover crop and in hedges and windbreaks. Winged bean (Psophocarpus tetragonolobus (L.) DC), on the other hand, is eaten as a pulse, but its primary use is its immature pods being eaten as a vegetable, and consequently winged bean is described in PROTA 2: 'Vegetables'. Species that are used as a cereal or pulse in tropical Africa but have another primary use are listed after the primary use cereals and pulses, and are fully described in other commodity groups. Some well-known species included in this list are: kodo millet (Paspalum scrobiculatum L.), lablab (Lablab purpureus (L.) Sweet) and winged bean (Psophocarpus tetragonolobus (L.) DC). Six species are treated which have two primary uses, including use as cereal or pulse, and consequently will be described in two commodity groups. These species are Arachis hypogaea L. (also in PROTA 14: 'Vegetable oils'), Glycine max (L.) Merr. (also in PROTA 14: 'Vegetable oils'), Phaseolus vulgaris L. (also in PROTA 2 'Vegetables'), Pisum sativum L. (also in PROTA 2 'Vegetables'), Vigna unguiculata (L.) Walp. (also in PROTA 2 'Vegetables'), and Sorghum bicolor (L.) Moench (also in PROTA 3: 'Dyes and tannins'). In PROTA 1: 'Cereals and pulses' comprehensive descriptions are given of 35 important species (15 cereals, 19 pulses and 1 pseudo-cereal). These major cereals and pulses comprise most cultivated species, but also several wild or partly domesticated ones. The accounts are presented in a detailed format and illustrated with a line drawing and a distribution map. In addition, accounts of 38 species of minor importance (22 cereals, 14 pulses and 2 pseudo-cereals) are given. Because information on these species is often scanty, these accounts are in a simplified format. For another

10 12 CEREALSAND PULSES 9 species (5 cereals and 4 pulses) the information was too scarce to justify an individual treatment and they have only been mentioned in the accounts of related species. Plant names Family: Apart from the classic family name, the family name in accordance with the Angiosperm Phylogeny Group (APG) classification is also given where it differs from the classic name. Synonyms: Only the most commonly used synonyms and those that may cause confusion are mentioned. Vernacular names: Only names in official languages of regional importance in Africa are included: English, French, Portuguese and Swahili. It is beyond the scope of PROTA to give an extensive account of the names of a species in all languages spoken in its area of distribution. Checking names would require extensive fieldwork by specialists. Although regional forms of Arabic are spoken in several countries in Africa, the number of African plant species that have a name in written, classical Arabic is limited. Arabic names are therefore omitted. Names of plant products are mentioned under the heading 'Uses'. Origin and geographic distribution To avoid long lists of countries in the text, a distribution map is added for major species. The map indicates in which countries a species has been recorded, either wild or planted. For many species, however, these maps are incomplete because they are prepared on the basis of published information, the quantity and quality of which varies greatly from species to species. This is especially the case for wild species which are not or incompletely covered by the regional African floras, and for cultivated species which are only planted on a small scale (e.g. in home gardens). For some countries (e.g. Central African Republic, Chad, Sudan, Angola) there is comparatively little information in the literature. Sometimes they are not covered by recent regional or national floras and although species may be present there, this cannot be demonstrated or confirmed. Properties The food value of the cereals and pulses is mentioned in the species accounts. The analytical method used to determine the various elements of the nutritional composition considerably influences the values found. For this reason a few standard sources were used wherever possible and the sources are mentioned in the text. These sources are: the USDA Nutrient database for standard reference; McCance & Widdowson's The composition of foods; FAO Food composition table for use in Africa. Apart from nutrients, this section includes other properties relevant to the respective uses.

11 INTRODUCTION 13 Description A morphological characterization of the species is given. The description is in 'telegram' style and uses botanical terms. Providing a description for the general public is difficult as more generally understood terms often lack the accuracy required in a botanical description. A line drawing is added for all major and some lesser-known species to complement and visualize the description. Management Descriptions of husbandry methods including fertilizer application, irrigation, and pest and disease control measures are given under 'Management' and under 'Diseases and pests'. These reflect actual practices or generalized recommendations, opting for a broad overview but without detailed recommendations adapted to the widely varying local conditions encountered by farmers. Recommendations on chemical control of pests and diseases are merely indicative and local regulations should be given precedence. PROTA will participate in the preparation of derived materials for extension and education, for which the texts in this volume provide a basis, but to which specific local information will be added. Genetic resources The genetic diversity of many plant species in Africa is being eroded, sometimes at an alarming rate, as a consequence of habitat destruction and overexploitation. The replacement of landraces of cultivated species by modern cultivars marketed by seed companies is another cause of genetic erosion. Reviews are given of possible threats for plant species and of the diversity within species. Information on ex-situ germplasm collections is mostly extracted from publications of the International Plant Genetic Resources Institute (IPGRI). References The main objective of the list of references given is to guide readers to additional information; it is not intended to be complete or exhaustive. Authors and editors have selected two categories of references; 'major references' are limited to 10 references (5 for minor species), the number of'other references' is limited to 20 (10 for minor species). The references listed include those used in writing the account. Where the internet was used, the website and date are cited.

12 14 CEREALS AND PULSES

13 Alphabetical treatment of cereals and pulses 15

14 16 CEREALSAND PULSES

15 AMARANTHUS 17 AMARANTHUS CAUDATUS L. Protologue Sp. pi. 2: 990 (1753). Family Amaranthaceae Chromosome number 2n - 32 Vernacular names - Grain amaranth, Inca wheat, jataco (En). Amarante-grain, blé des Incas (Fr). Amarante de cauda (Po). - African spinach, Indian spinach (En). Brède malabar (Fr). Bredo (Po). Mchicha (Sw). - Love-lies-bleeding, red-hot cattail, foxtail (En). Queue de renard, discipline des religieux (Fr). Cauda de raposa, moncos de peru (Po). Origin and geographic distribution Amaranthus caudatus is not known from the wild. It originated in the Andes, possibly as a hybrid between the wild Amaranthus hybridus L. subsp. quitensis (Kunth) Costea & Carretero and the cultivated Amaranthus cruentus L. (originating from Central America). Amaranthus caudatus has long been grown as a food crop in the Andes, e.g. by the Incas, and the greatest genetic variation occurs in this area (Ecuador, Peru, Bolivia and Argentina). The earliest archaeological evidence of its cultivation dates from 2000-year-old tombs in northwestern Argentina. The chronicler Cobo wrote in 1653 that in the city of Guamanga (now Ayacucho) delicious sweets were prepared from amaranth and sugar. Amaranthus caudatus was introduced into Europe in the 16 th century and it was spread to Africa and Asia later. The cultivated area has notably decreased over the years, but Amaranthus caudatus has remained a grain crop in Ecuador, Peru, Bolivia and Argentina. It is occasionally grown as a grain Amaranthus caudatus - planted crop in Asia and Africa. As an ornamental it is grown throughout much of the tropics and in some temperate regions. The exact distribution of Amaranthus caudatus in Africa is not known, because it has often been confounded with other Amaranthus species. It is grown in Ethiopia and Eritrea for its grain and as an ornamental; it has also been grown in Uganda and Kenya and has been recorded from several other countries in Central, East and southern Africa, and the Mascarene Islands, where it may also be found as a weed escaped from cultivation. Uses Amaranthus caudatus seeds are toasted and popped, ground into flour or boiled for gruel. For making leavened foods, they must be blended with wheat. The seeds are fermented to make alcoholic beverages, e.g. beer ('tella') in Ethiopia. In Ethiopia cooked seeds are made into porridge, and ground seeds are mixed with tef to prepare pancake-like bread ('injera'). Seeds can be sprouted for use as a nutritious vegetable. The leaves are eaten as a vegetable like those of other amaranth species, e.g. in Peru and Ethiopia. Harvest residues are used for feeding livestock and for thatching. In South America grain amaranths are traditionally used in medicine, folk festivals, and as dye sources. In Ethiopia the root is used as a laxative, and the seed for expelling tapeworms and for treating eye diseases, amoebic dysentery, and breast complaints. In India the plant is taken as a diuretic and it is applied to sores. Amaranthus caudatus is widely grown as an ornamental ('Love-lies-bleeding'). Production and international trade No statistics are available on production and trade of grain amaranths in general and Amaranthus caudatus in particular. Reports from the 1990s mention several thousands of ha of grain amaranths in China, similar large production areas in Argentina, and about 2000 ha in the United States. Estimates for India and Nepal are up to 4000 ha. In Peru, there are over 1000 ha under grain amaranths (mainly Amaranthus caudatus) in the high Andean region alone. The United States imports large quantities of grain amaranth from Mexico. Properties Grain amaranth (species unspecified) seeds contain per 100 g edible portion: water 9.8 g, energy 1565 kj (374 kcal), protein 14.5 g, fat 6.5 g, carbohydrate 66.2 g, dietary fibre 15.2 g, Ca 153 mg, Mg 266 mg, P 455 mg, Fe 7.6 mg, Zn 3.2 mg, vitamin A 0 IU, thiamin 0.08 mg, riboflavin 0.21 mg, niacin 1.29 mg, vitamin B mg, folate 49 ug and

16 18 CEREALS AND PULSES ascorbic acid 4.2 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 181 mg, lysine 747 mg, methionine 226 mg, phenylalanine 542 mg, threonine 558 mg, valine 679 mg, leucine 879 mg and isoleucine 582 mg. The main fatty acids are (per 100 g edible portion): linoleic acid 2834 mg, oleic acid 1433 mg, palmitic acid 1284 mg and stearic acid 220 mg (USDA, 2004). Amaranth grain is renowned for the excellent quality of its protein because of the high lysine content. Gluten-free types exist and are suitable for people with coeliac disease. The starch mainly consists of amylopectin, with only5 7% amylose. The rather small starch granules (1-3 im in diameter) have drawn wide attention for industrial uses of grain amaranths. The oil contains 4-11% of the triterpenoid squalene, which may find a niche market in products such as lubricants in the computer industry and in cosmetics. The stems, leaves and seeds of Amaranthus caudatus contain water-soluble red-violet betacyanin pigments. In aqueous plant extracts they consist on average of 81% amaranthine and 19% isoamaranthine; in dried extracts of 67% amaranthine and 33% isoamaranthine. Dissolved in water the pigments are unstable except at low temperatures in the dark and in the absence of air; dried pigments are very stable at room temperature. The seed also contains red-coloured lectins sometimes also referred to as amaranthine. Two peptides isolated from the seed of Amaranthus caudatus (Ac-AMPl and Ac-AMP2) have shown strong antifungal and some antibacterial activity. Description Annual erect herb up to 1.5( 2.5) m tall, commonly reddish or purplish throughout; stem rather stout, not or sparingly branched, glabrous or thinly furnished with rather long hairs. Leaves arranged spirally, simple and entire; stipules absent; petiole up to 8 cm long, but never longer than the blade; blade broadly ovate to rhomboid-ovate or ovateelliptical, (-20) cm x 1-8 cm, base cuneate to attenuate, apex obtuse to acute, glabrous or sparsely hairy on main veins below, pinnately veined. Inflorescence large (up to 1.5 m) and complex, consisting of numerous agglomerated cymes arranged in axillary and terminal spikes, the terminal one pendant to erect; bracts 3 4 mm long, membranous, pale, with a long awn. Flowers unisexual, sessile; with 5 mucronate tepals 2 3 mm long; male flowers with 5 stamens c. 1 mm long; female flowers with superior, 1-celled ovary crowned Amaranthus caudatus - 1, upper part of flowering plant; 2, dehisced fruit. Redrawn and adapted by Iskak Syamsudin by 3 stigmas. Fruit an ovoid-globose capsule mm long, circumscissile, almost smooth or slightly furrowed, abruptly narrowed to a short thick beak, 1-seeded. Seed almost globose, mm long, smooth and shining, pale coloured (ivory), reddish or dark brown. Other botanical information Amaranthus comprises about 70 species, of which about 40 are native to the Americas. It includes at least 17 species with edible leaves and 3 grain amaranths. Amaranthus caudatus is part of the socalled Amaranthus hybridus aggregate, a group of species in which taxonomie problems are far from clarified, especially because of common hybridization and names often being misapplied. Some recognized species of this aggregate are cultivated taxa. Amaranthus caudatus is one of these, as are the other grain amaranths, Amaranthus cruentus L. and Amaranthus hypochondriacus L., which are included in PROTA 2 'Vegetables'. Amaranthus caudatus can be distinguished by its usually long and pendant terminal spike and comparatively broad tepals of female flowers. A classification in cultivar groups might be more appropriate for the cultivated taxa. Amaranthus caudatus shows a wide genetic variation and diversity of plant form, ranging from erect to completely decumbent. Two types have been distinguished: subsp. caudatus, the

17 AMARANTHUS 19 main type, and subsp. mantegazzianus (Pass.) Hanelt, grown as a grain crop in the valleys of the Andes in north-western Argentina. The latter can be distinguished by its determinate club-shaped inflorescence branches, due to a single recessive gene. According to some, it should be considered as a separate species Amaranthus mantegazzianus Pass., an opinion which has recently been supported by the results of seed protein studies. Growth and development Germination of Amaranthus caudatus seed accelerates with increasing temperature in the range 5-35 C; no germination occurs at 0 C. Seedlings normally emerge 3-5 days after sowing and early growth is slow. Flowering begins days after emergence. Outcrossing rates of 6-29% have been recorded in Amaranthus caudatus. The total crop duration in Peru ranges from 3 4 months at 1800 m altitude to 9 months at 3200 m altitude; in Kenya it is normally days. A single plant may yield more than 50,000 seeds. Amaranthus caudatus is a C4- cycle plant, giving higher yields at higher light intensities and temperatures, and being efficient in water use. Ecology In the tropics Amaranthus caudatus performs well under cool, dry highland conditions. It is more tolerant to chilling than the other 2 grain amaranths and is grown at higher altitudes. In East Africa it is found at m altitude, in South America at m. In Peru it is grown in regions with an average annual rainfall of 550 mm. The photoperiodic response is marked, with flowering being promoted by short photoperiods. Amaranthus caudatus can be grown in sandy and clay soils. In general grain amaranths prefer well-drained neutral or alkaline soils (ph>6), but some types are well adapted to acid and mildly saline soils. Propagation and planting Amaranthus caudatus is propagated by seed. Its 1000-seed weight is g. Seed scarification with concentrated sulphuric acid or sandpaper enhances germination. Common seed rates in Peru are 8-18 kg/ha, but in Kenya seed rates of only 1-2 kg/ha are common. With improved cultivars in Peru densities of 400, ,000 plants/ha gave the highest yields. Emergence of seedlings is best when the seed is sown at a depth of cm, but in dry, hot areas deeper sowing may be necessary. However, emergence is seriously lowered if the sowing depth exceeds 5 cm. Amaranthus caudatus is grown in sole cropping as well as in intercropping systems, e.g. with maize in South America and Ethiopia. Sometimes it is planted as a guard-row for a main crop, e.g. bean, maize or millet. In Ethiopia the plants are sometimes allowed to sow themselves. Management Once they are established, grain amaranths compete well with weeds, but they must be weeded at least once during the first month. Hilling the plants when they are about 30 cm tall helps to control weeds and to reduce lodging; it may also control Alternaria disease. In Peru Amaranthus caudatus is sometimes grown with supplemental irrigation. Results of fertilizer trials are inconclusive, and in general grain amaranths grow well under widely differing nutrient levels. In Peru manure is usually applied. Diseases and pests In Amaranthus caudatus fungal diseases have been observed caused by Alternaria, Mycoplasma and Sclerotinia spp. Pests causing economic damage to grain amaranths are mainly leaf-eating caterpillars (Heliothis, Hymenia, Spodoptera), stinkbugs (e.g. Lygus on the inflorescence), stem-boring larvae of weevils, grasshoppers and aphids. Harvesting Harvesting of Amaranthus caudatus is difficult because of asynchronous ripening. The crop may be harvested once-over by cutting the inflorescences when the plants are still green, to avoid seed shattering. In Peru the plants are cut at ground level with a sickle, bundled, and left to dry in the field for 1 2 weeks. In dry, irrigated areas senescence can be induced by stopping irrigation 2 weeks before the harvest. Leaves may be harvested once or several times to be used as a vegetable, before the grain or total biomass is harvested at maturity for food or forage. Yield Seed yields of grain amaranths vary widely, from as low as kg/ha to as high as kg/ha. In north-western India, where all 3 grain amaranth species are grown, yields of Amaranthus caudatus and Amaranthus cruentus are lower than those of Amaranthus hypochondriacus. Handling after harvest After drying in the field, the plants are threshed by hand or machine, and the seed is cleaned. Additional drying to reduce the moisture content to 12% may be necessary for safe storage. Genetic resources Large germplasm collections of Amaranthus caudatus are kept in Peru (Universidad Nacional de San Antonio Abad del Cusco (UNSAAC/CICA), Cusco, 1600 acces-

18 20 CEREALS AND PULSES sions; Universidad Nacional Agraria La Molina, Lima, 333 accessions; Estación Experimental Agraria Banos del Inca, Cajamarca, 257 accessions) and the United States (Organic Gardening and Farming Research Center, Kutztown, Pennsylvania, 297 accessions). The only germplasm collection of Amaranthus caudatus in Africa recorded by IPGRI is in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 4 accessions). Breeding Major breeding objectives for Amaranthus caudatus and other grain amaranths are improved harvestability (less lodging, less shattering, better uniformity of maturity), increased seedling vigour, increased resistance to pests and higher yields. In Peru selection in landraces has led to the release of the Amaranthus caudatus cultivars 'Noel Vietmeyer', 'Oscar Blanco' and 'Alan Garcia'. Genetic studies have identified marker loci for traits such as pigmentation patterns, inflorescence morphology and seed characters in Amaranthus caudatus and other grain amaranths. Research is needed on hybridization barriers among grain amaranth species as well as on the biosystematic identity of the species; only then can the information be indisputably related to species. Prospects In tropical Africa Amaranthus caudatus is presently cultivated on a very limited scale and, like the other grain amaranths, it probably does not have much future as a grain crop, because it cannot compete with cereals that are more productive and easier to grow. On a worldwide scale grain amaranths have some potential, because of their favourable agronomic characteristics, excellent nutritional qualities and diverse food and technical applications. Amaranths are also considered to have prospects in food colouring. Major references Agong & Ayiecho, 1991; Bale & Kauffman (Editors), 1992; Brenner et al., 2000; Costea, Sanders & Waines, 2001; Jain & Sutarno, 1996; National Research Council, 1984; National Research Council, 1989; Sauer, 1967; Townsend, 2000; Williams & Brenner, Other references Berghofer & Schoenlechner, 2002; Broekaert et al., 1992; Cai, Sun & Corke, 1998; Cai et al., 1998; Coons, 1982; CSIR, 1950; Drzewiecki, 2001; Getahun, 1976; Gutterman, Corbineau & Come, 1992; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hauman, 1951; Janick & Simon (Editors), 1990; Joshi, Mehra & Sharma, 1983; Paredes-López (Editor), 1994; Sauer, 1976; Stallknecht & Schulz-Schaeffer, 1993; Sun, Chen & Leung, 1999; Townsend, 1985; Townsend, 1994; USDA, Sources of illustration Grubben, Authors S.G. Agong ARACHIS HYPOGAEA L. Protologue Sp. pi. 2: 741 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 40 Vernacular names Groundnut, peanut, earthnut, monkey nut (En). Arachide, cacahuète, cacahouète, pistache de terre (Fr). Amendoim, mandobi, caranga (Po). Mjugu nyasa, mnjugu nyasa, karanga (Sw). Origin and geographic distribution Groundnut originated in the area of southern Bolivia and north-western Argentina. It is an ancient crop of the New World and was widely grown in Mexico, Central America and South America in pre-columbian times. Domesticated groundnut had already evolved into several types before it was introduced into the Old World by Spanish and Portuguese explorers. Two-seeded types originating from Brazil were brought to West Africa, and 3-seeded types originating from Peru were taken from the west coast of South America to the Philippines, from where they spread to Japan, China, Indonesia, Malaysia, India, Madagascar and East Africa. In the late 1700s 'Spanish' groundnut types were introduced into Europe from Brazil. The first successful introduction in North America concerned small-seeded 'runner'-type groundnuts, Arachis hypogaea - planted

19 ARACHIS 21 probably originating from northern Brazil or the West Indies. Groundnut is now grown in most tropical, subtropical and temperate countries between 40 N and 40 S latitude. It is grown throughout tropical Africa and is a major cash crop in Senegal, Gambia, Nigeria and Sudan. Uses Groundnut seed is mainly used as food and for oil extraction. The seeds are eaten raw, boiled or roasted, made into peanut butter, confectioneries and snack foods, and are used for thickening soups or made into sauces to be eaten with meat and rice. In northern Nigeria groundnut flour is mixed with 'gari' (coarse fermented cassava meal) and made into balls that are eaten as a snack. In the United States and Argentina most of the crop is used as food, but in most other countries the primary use of groundnut is for the oil market. Worldwide, more than 50% of groundnut production is crushed into oil for human consumption or industrial use (e.g. in cosmetics). In countries such as Senegal, Gambia and Nigeria oil extraction has been an important cottage industry for years. The use of groundnut in confectionery and for oil and meal production is increasing, and there is gradual shift taking place from oil and meal to confectionery use, especially in Latin America and the Caribbean. In South America groundnut seeds are fermented into alcoholic drinks. The presscake from oil extraction is a feed rich in protein, but it is also made into groundnut flour, which is used in many human foods. Fermented groundnut cake is eaten fried in Indonesia. The cake finds industrial application in the production of glues, sizes for paper and starches for laundering and textile manufacture. Protein from groundnut cake is made into a wool-like fibre, which can be blended with wool or rayon. Groundnut shells are used as roughage in fodder, as fuel, fertilizer, mulch, in the manufacture of particle board and building blocks, and can be used as a source of activated carbon, combustible gases, organic chemicals, reducing sugars, alcohol and extender resins. Young groundnut pods and leaves are consumed as a vegetable; in West Africa the leaves are added to soups. The foliage is an important fodder, especially in the Sahel; it may be eaten fresh or as hay or silage. In southern India the haulms are sometimes applied as a green manure. Groundnut has a range of uses in traditional African medicine. Pod extracts are taken as a galactagogue, and used as eye-drops to treat conjunctivis. Macerations of peeled seeds are drunk to treat gonorrhoea, macerations of the seed coats against syphilis, while macerations of the seed coats and shells are applied against ophthalmia. Sap of ground leaves and seeds is used for ear-drops against ear discharge. Leaf macerations are drunk as a diuretic. Leaf infusions are drunk against female infertility, and used for eye-drops to treat eye injuries and cataract. Plant ash with salt is applied in case of caries. Pod extracts and young plants are credited with aphrodisiac properties. The plant is also used to relieve cough and is considered emollient and demulcent; emulsions are taken to treat pleurisy, enteritis (including colitis), and dysuria. Agglutinins (lectins) from groundnut seeds are often used in medical research for histochemical investigations. Production and international trade According to FAO estimates, the average world production of groundnut pods in amounted to about 34.4 million t/year from 24.4 million ha. The main producing countries are China (14.0 million t/year in , from 4.9 million ha), India (6.1 million t/year from 6.7 million ha), Nigeria (2.8 million t/year from 2.7 million ha), the United States (1.7 million t/year from 0.5 million ha), Indonesia (1.3 million t/year from 0.7 million ha) and Sudan (1.1 million t/year from 1.7 million ha). The total production in sub-saharan Africa was 8.2 million t/year from 9.5 million ha. Average world export of groundnut seeds amounted to 1.1 million t/year in The main exporters were China (321,000 t/year), Argentina (201,000 t/year) and the United States (171,000 t/year). Export of groundnut seeds from sub-saharan Africa was 64,000 t/year, with Gambia as main exporter (26,000 t/year). Average world export of groundnut pods in was only 176,000 t/year, with China as main exporter (73,000 t/year). Exports of groundnut pods from sub-saharan Africa were negligible. The world production of groundnut oil in was 5.1 million t/year. The main producers are China (2.0 million t/year), India (1.4 million t/year), Nigeria (480,000 t/year), Senegal (178,000 t/year) and Sudan (162,000 t/year). The production in sub-saharan Africa was 1.2 million t/year. The world groundnut cake production in was 6.9 million t/year, mainly from China (2.6 million t/year), India (1.9 million t/year) and Nigeria (750,000

20 22 CEREALSAND PULSES t/year). The production in sub-saharan Africa was 1.6 million t/year. Average world export of groundnut oil in was 271,000 t/year, with as main exporters Senegal (83,000 t/year) and Argentina (69,000 t/year). The total export of groundnut oil from sub-saharan Africa was 114,000 t/year. The main importers were France (68,000 t/year), Italy (46,000 t/year) and the United States (25,000 t/year). Average groundnut cake export amounted to 280,000 t/year. Major exporters were Senegal (103,000 t/year), Argentina (51,000 t/year), India (43,000 t/year) and Sudan (35,000 t/year). Total groundnut cake export from sub-saharan Africa was 143,000 t/year. The main importers were France (129,000 t/year) and Thailand (53,000 t/year). Properties Mature groundnut seeds contain per 100 g edible portion (average of several types, which show little difference): water 6.5 g, energy 2374 kj (567 kcal), protein 25.8 g, fat 49.2 g, carbohydrate 16.1 g, dietary fibre 8.5 g, Ca 92 mg, Mg 168 mg, P 376 mg, Fe 4.6 mg, Zn 3.3 mg, vitamin A 0 IU, thiamin 0.64 mg, riboflavin 0.14 mg, niacin 12.1 mg, vitamin P> mg, folate 240 \ig and ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 250 mg, lysine 926 mg, methionine 317 mg, phenylalanine 1337 mg, threonine 883 mg, valine 1082 mg, leucine 1672 mg and isoleucine 907 mg. The principal fatty acids are per 100 g edible portion: oleic acid 23.7 g, linoleic acid 15.6 g and palmitic acid 5.2 g (USDA, 2004). Groundnut seeds yield 42-56% oil. Groundnut oil contains 36-72% oleic acid, 13 48% linoleic acid and 6-20% palmitic acid. The ratio of oleic to linoleic acid has an important bearing on the stability of the oil; the higher the ratio, the more stable the oil and the longer its shelf life. The ratio in mature seeds can range from less than 1.0 to greater than 3.0; more than 1.3 is generally considered satisfactory by processors. The presscake contains 40-50% easily digestible protein, 20-25% carbohydrate and 5-15% residual oil. Groundnut pods have a thick woody shell containing normally 2-3 seeds ('kernels'). The seed coat constitutes about 4 5%of the seed weight, the cotyledons 90-94% and the germ 3-4%. The major components of the seed coat are carbohydrate, cellulose and protein. Oil and protein are the main constituents of the germ and cotyledons. The germ is associated with bitter components. An important problem in groundnut production is aflatoxin contamination by Aspergillus fungi. Aflatoxin has immunosuppressive effects and epidemiological studies, also in Africa, have shown a positive correlation between aflatoxin intake and the incidence of liver cancer. After industrial oil extraction, aflatoxin remains in the cake, and the refined oil is free of aflatoxin, but in case of small-scale extraction, the nonrefined oil may be contaminated. Groundnut is one of the most allergenic foods known and may cause anaphylactic reactions. Groundnut seeds contain a haemostatic factor which can be useful in haemophilia. Groundnut oil is mildly laxative. Adulterations and substitutes Groundnut oil can be substituted by other vegetable oils, e.g. from maize, soya bean and sunflower. Description Annual herb, with erect or prostrate stem up to 70 cm long; root system consisting of a well-developed taproot with many lateral roots, up to 135 cm deep, but generally restricted to the upper layers of the soil. Leaves arranged spirally, 4-foliolate with two opposite pairs of leaflets; stipules cm long, with a slender free tip, but fused to the petiole for about half their length; petiole cm long; petiolules 1 2 mm long; leaflets Arachis hypogaea - 1, branch with flowers and fruit; 2, inflorescence; 3, fruit; 4, seeds. Source: PROSEA

21 AEACHIS 23 obovate or elliptical, 1-7 cm x cm, cuneate-rounded at base, rounded or emarginate and mucronate at apex. Inflorescence an axillary, 2-5-flowered spike. Flowers bisexual, papilionaceous, sessile; receptacle long and slender, pedicel-like, up to 4 cm long; calyx with 4 upper lobes joined, lower lobe free; corolla pale yellow to orange-red, rarely white, standard rounded, c. 1.5 cm x 1.5 cm, wings shorter, keel incurved; stamens (8-) 10, alternately with small, globular anthers and larger, oblong anthers, joined at base; ovary superior but situated at base of receptacle tube, style free within the tube, very long, ending in a minute club-shaped stigma. Fruit an oblong or sausage-shaped pod, borne at the tip of an elongated fruit stalk ('peg') up to 20 cm long,1 8 cm x cm, surface constricted to varying degrees between the seeds and reticulately veined, 1 6-seeded. Seeds cylindrical to ovoid, 1-2 cm x cm, with pointed or flattened ends, enclosed in a thin papery seed coat ranging in colour from white to deep purple. Seedling with epigeal germination; cotyledons thick and fleshy. Other botanical information Arachis comprises about 70 species, all distributed in South America. The centre of origin of Arachis is the Mato Grosso region of Brazil. Arachis hypogaea is by far the most economically important species in this genus, but several other species have been cultivated for their seeds, including Arachis villosulicarpa Hoehne and Arachis stenosperma Krapov. & W.C.Greg. High levels of resistance to many diseases and pests of groundnut have been recorded in other Arachis species. Many of them are closely related to groundnut and include the other 26 species in section Arachis. Several diploid species have been suggested as wild progenitors of groundnut, but molecular and cytogenetic studies indicate that Arachis duranensis Krapov. & W.C.Greg, and Arachis ipaensis Krapov. & W.C.Greg, are most closely related to the progenitors of allotetraploid domesticated groundnut. Arachis monticola Krapov. & Rigoni is the only other tetraploid species in the section; it is very closely related to Arachis hypogaea and may be the direct descendant of the original hybrid between the 2 diploid progenitor species. Hybrids between Arachis hypogaea and other Arachis species have been produced by direct hybridization and by first creating autotetraploids or allotetraploids from the diploid species before making crosses. Hybrids show high levels of sterility due to ploidy level differences and genome incompatibility. There is considerable variation in Arachis hypogaea and two subspecies have been distinguished: subsp. hypogaea and subsp. fastigiata Waldron. Subsp. hypogaea ('runner type') is characterized by a more prostrate growth habit without flowering branches on the main stem, and with the cotyledonary lateral branches carrying alternate pairs of vegetative and reproductive secondary branches; it is usually late-maturing. It includes the 'Virginia' types groundnut. Subsp. fastigiata ('bunch type') is characterized by an erect growth habit with flowering branches on the main stem, and without a regular pattern in the sequence of vegetative and reproductive branches; and it is early-maturing. It includes the 'Spanish' and 'Valencia' types groundnut. Most groundnut cultivars grown in West Africa belong to subsp. hypogaea; most of those in East Africa to subsp. fastigiata. Subsp. hypogaea is mainly used for food, and subsp. fastigiata, which has a higher oil content, as a source of oil. Growth and development Seeds of "Virginia' types have a dormancy period of 1-3 months, whereas 'Spanish' and "Valencia' types are without dormancy. The optimum soil temperature for seed germination is C. Low temperatures retard germination and development and increase the risk of seedling diseases. Upon germination, the primary root elongates rapidly, reaching cm before lateral roots appear. As growth proceeds, the outer layer of the primary root of a seedling is sloughed off so that root hairs do not form. Branching is dimorphic, with vegetative branches and reduced reproductive branches. Secondary and tertiary vegetative branches can develop from the primary vegetative branches. Flowering may start as early as 20 days after planting, but days after planting is more usual. The number of flowers produced per day decreases as the seeds mature. Up to 50% of the embryos may abort even under ideal environmental conditions, but this percentage becomes much higher during times of drought or other environmental stress. However, plants can produce a 'second crop' of seeds if adequate moisture becomes available again. Groundnut is self-pollinating, but outcrossing can occur when bees pollinate the flowers. Groundnut generally produces more flowers under long day conditions, but reproductive efficiency is greater under short days. Only one

22 24 CEREALSAND PULSES of the flowers in an inflorescence opens at a given time. Flowers wither within 24 hours after anthesis. Fertilization usually occurs within 6 hours after pollination, when the basal part of the ovary starts elongating into a structure called 'peg'. The embryo initiates a growth phase until it reaches an 8-16-cell stage. It then becomes quiescent during the 5-15 days required for the 'peg' to enter the soil. The 'peg' stops elongating within a day or two after soil penetration, the embryo then restarting growth. In wild Arachis species the 'peg' may continue to grow to a length of nearly 2 m. Seeds in 'Spanish'-type cultivars usually mature within days after planting, whereas 'Virginia'-type cultivars take 130 days or more. Pods of the same size may differ significantly in maturity and seed weight. Groundnut is usually effectively nodulated by N2-fixing Bradyrhizobium bacteria. Because root hairs are absent, the bacteria infect the root through cracks in the epidermis near multicellular hairs at the basis of the root. Ecology The optimum mean daily temperature for groundnut growth is C; growth ceases when temperature drops below 15 C. Groundnut is mainly grown in areas with an average annual rainfall of mm; mm of rain reasonably well distributed over the growing season allows satisfactory production. Nevertheless, groundnut is drought-tolerant and can withstand severe lack of water, though yield is generally reduced. A dry period is required for ripening and harvesting. The phenology of groundnut is determined primarily by temperature, with cool temperatures delaying flowering. In controlled environments, photoperiod has been shown to influence the proportion of flowers producing pods and distribution of assimilates between vegetative and reproductive structures (harvest index) in some cultivars. Long photoperiods (greater than 14 hours) generally increase vegetative growth and short photoperiods (less than 10 hours) increase reproductive growth. Groundnut can be grown up to 1500 m altitude. The best soils for groundnut are deep (at least cm), friable, well-drained sandy loams, well-supplied with calcium and a moderate amount of organic matter. It is important to maintain near to neutral soil ph levels and Ca:K ratios lower than 3. Propagation and planting Groundnut is propagated by seed, but vegetative propagation using cuttings is possible. The 1000-seed weight ranges from 150 g to more than 1300 g. Sowing high-quality seed in a well-prepared, moist seedbed is essential for crop establishment. Groundnut seeds are often planted at a depth of 4-7 cm at a rate of kg/ha. Groundnut pods intended for sowing are often hand-shelled 1-2 weeks before sowing. Only fully mature pods are selected. Before sowing, groundnut seed may be treated with a fungicide to control seedling diseases. In general, early sowing improves yields and seed quality. Early sown crops also suffer less risk of disease such as groundnut rosette virus. However the appropriate sowing date depends on the maturity period of the cultivar. Small-seeded 'Spanish' types are spaced at cm between rows and 10 cm within the row. This gives an optimum plant population of 133, ,000 plants per ha. Large-seeded "Virginia' types are spaced at 75 cm between rows and 15 cm within the row, giving an optimum plant population of 89,000 plants per ha. Groundnut can be grown on the flat, or on ridges as is often the case in Malawi. Groundnut grown on ridges tends to give higher yields, probably because of more loose soil favourable for pod development and easier uprooting. In tropical Africa groundnut is grown as a sole crop or intercropped between rows of cereals such as maize, sorghum or pearl millet. Management Groundnut does not compete effectively with weeds, particularly in the early stages of development. The crop should be thoroughly weeded within the first 45 days. Once the development of the 'peg' begins, earthing-up is kept to a minimum. Weeds at this stage are hand pulled. Pre-and postemergence herbicides may be used to eradicate weeds, but they are too expensive for most small-scale farmers in Africa. In sound rotation systems, groundnut benefits from residual fertility; in general no additional fertilizer is given if the crop is sown on a well-managed soil previously treated with a balanced fertilizer. However, in order to ensure good crop establishment, high yield and good seed quality, a fertilizer containing Ca, such as gypsum or single superphosphate, should be applied. Calcium is absorbed directly by the pods if soil moisture is adequate. A shortage of Ca in the zone where the pods develop will result in empty pods, particularly in cultivars of the 'Virginia' type. Groundnut is normally a rainfed crop, but it is grown under irrigation in Sudan. Groundnut should preferably not be grown in the same field more than once in 3 years to

23 ARACHIS 25 limit damage by soil-borne diseases, nematodes and weeds. It fits into a wide range of rotations and it can follow any clean-weeded crop, e.g. maize, sorghum, pearl millet, cassava, sweet potato or sunflower. To reduce the incidence of diseases and pests, groundnut should not be sown after cotton or tobacco. Groundnut does well on virgin land or immediately following a grass ley or well-fertilized crop such as maize. The intensity of management of groundnut varies considerably around the world, depending on the economic return for the crop or the role of groundnut in the farming system. In the United States, Australia and parts of South America the crop is grown with intensive management, generally with high levels of mechanical and chemical inputs. In many countries groundnut is grown as a cash crop primarily for export. Diseases and pests Groundnut is susceptible to a number of diseases, such as early leaf spot (Cercospora arachidicola), late leaf spot (Cercosporidium personatum, synonym: Cercospora personata), rust (Puccinia arachidis), groundnut rosette (caused by a complex of 3 agents: groundnut rosette virus (GRV), groundnut rosette assistor virus (GRAV) and a satellite RNA) and aflatoxin contamination caused by Aspergillus fungi. Foliar diseases of groundnut are among the most important yieldlimiting factors in groundnut production. Early and late leaf spots and rust together may cause up to 70% yield losses; even where fungicides are applied significant yield reductions occur. Spraying with fungicide when the disease appears controls both leaf spots effectively. Dusting groundnut leaves with sulphur, early in the morning when there is still dew on the leaves, has been reported to control both early and late leaf spots. The use of sulphur has also been observed to increase leaf retention, thus increasing the quantity of leafy stems available for livestock feed. Cultural practices to control leaf spots include crop rotation and burning of crop residues. Cultivars with partial resistance to leaf spots have been developed. Rust generally occurs sporadically and at low severity, although it can cause crop losses up to 40% when an epidemic occurs. The cultural practices and fungicidal control measures recommended for leaf spots are also applicable to rust. Resistant cultivars are available. Groundnut rosette virus, transmitted by the aphid Aphis craccivora, is endemic to sub-saharan Africa and widely prevalent in Ghana, Nigeria, Malawi and Zambia. It is the most destructive disease of groundnut leading to % yield loss. Early sowing at high plant populations controls the spread of groundnut rosette by giving complete soil coverage as quickly as possible and restricting the movement of aphids. Cultivars resistant to groundnut rosette are widely grown in Africa. In Malawi it is common practice for farmers to interplant groundnut and cowpea to control groundnut rosette. Aspergillus fungi can invade groundnut pods and seeds, producing toxic compounds known as aflatoxin. Contaminated produce can be poisonous to people and livestock, and cannot be exported. Aflatoxin contamination also affects groundnut seed, leading to low germination percentage and poor seedling establishment. It can occur before harvest, during field drying and curing, and in storage. Preharvest contamination is likely to be most serious under drought. Post-harvest contamination occurs if groundnut pods or seeds become moist and/or damaged. Various methods are used to control aflatoxin. They include avoiding mechanical damage to pods or seeds during weeding, harvesting and storage, harvesting as soon as the pods are mature, proper drying and curing, and storing in the shell at low temperature under moisture-free conditions. Root-knot nematodes (Meloidogyne spp.) may cause considerable yield loss in groundnut; they can be controlled by crop rotation. On a global scale the most important insect pests include aphids (Aphis craccivora), thrips (Frankliniella spp.), jassids (Empoasca dolichi), white grubs (larvae of various beetles), termites (mainly Microtermes sp.) and the red tea bug Hilda patruelis. False wireworms and millipedes seem to occur less frequently. In general, soil pests cause more damage than foliage feeders or sucking pests. However, aphids are particularly harmful because they transmit groundnut rosette virus. In Asia and Africa white grubs, termites, millipedes and ants are important pests; in the United States the lesser cornstalk borer (Elasmopalpus lignosellus) and the southern corn rootworm (Diabrotica undecimpunctata) are the main insect pests of groundnut. Pests attacking stored groundnut pods and seeds include bruchids (Caryedon serratus, Callosobruchus spp., Acanthoscelides spp.) and flour beetles (Tribolium spp.). Parasitic plants (Alectra vogelii Benth. and Striga spp.) are recorded as causing damage to groundnut in various African countries. Harvesting The indeterminate flowering

24 26 CEREALS AND PULSES pattern of groundnut makes proper timing of harvest difficult, even though such timing is crucial for obtaining maximum yield and quality. Harvest at the proper time ensures that the maximum number of pods have attained their greatest weight and that pods are not falling off. Methods to determine the proper time for harvesting groundnut are available, but some are environment-specific or are prohibitively expensive. Presently only the shellout method and the hull-scrape method are widely used for groundnut maturity determination. The shell-out method is based on colour changes within the pod wall ( 'hull') that occur as the pod matures. The internal pod wall surface of most cultivars changes from white to brown or black blotches covering a large percentage of the area. The colour of the seed coat changes from white to dark pink or tan at the same time. A sample of plants is taken and pods opened. The percentage of pods with dark colour inside the pod wall is determined. Harvesting should begin when the percentage is 60-80, but recommendations vary. The shellout method is widely used because it can directly be used in the field without further handling of pods, requires no equipment and provides an immediate answer. The hull-scrape method, developed in the early 1990s, is currently accepted as the most accurate means of assessing the maturity of 'runner'-type groundnuts. The method is based on the fact that the pod mesocarp (the area just beneath the pale brown coloured exterior of the groundnut pod) changes from white to yellow to orange to brown to black as the crop matures. The method requires colour charts and a pocket knife to scrape the pod surface. Harvesting is carried out manually in most parts of Africa, as well as Asia. In the United States harvesting is normally done using a digger shaker inverter. When plants are harvested manually, they are loosened with a hoe and pulled out of the ground, after which they are turned to expose the pods to the sun to facilitate drying. When dry, the pods are ripped off the plants. With mechanical harvesting, the plants are cleanly removed from the soil and deposited in inverted windrows. Pods have to remain in the windrows until the average moisture content is 18-24%. Pods are then picked using a combine. Rainfall during windrowing may promote mould growth resulting in reduced milling quality. Yield In tropical Africa the average yield of groundnut pods in the early 2000s was about 850 kg/ha, which is only slightly higher than the average yield in the 1970s (730 kg/ha). National average yields of groundnut pods in tropical Africa range from kg/ha. Average world yields of groundnut pods increased from 0.9 t/ha in the 1970s to 1.4 t/ha in the early 2000s. With good management practices and proper disease control, yields up to 5 t/ha can be achieved. On average 100 kg of pods yield 70 kg of seeds, containing 35 kg oil. Handling after harvest Produce quality is closely related to proper harvesting date, harvesting method and drying; every step is critical to obtaining or maintaining quality. Groundnut pods are dried to an average moisture content of about 10%. Removing foreign materials early helps to maintain quality during storage. Cleaning equipment to remove the foreign material has been developed and includes sand screens and belt screens. Groundnut pods are stored in granaries, tanks, bins, concrete silos, warehouses or in the open. In storage, ventilation is crucial to prevent moisture build up which can promote mould growth and aflatoxin production. Excessive heat should be avoided. Storage structures should be examined frequently for moisture and insect problems as these can greatly reduce quality. Seeds can be protected from mechanical damage by storage and transport in the pods. In many areas groundnut is only shelled when it is to be used or sold; in local markets unshelled pods are often offered for sale. Both mechanical and manual shelling are common. Groundnut removed from storage is transported to shelling centres where the pods are graded, cleaned and shelled, and the seeds are separated into commercial grade sizes. Shelling operations may damage the seeds. Shelling of 100 kg of groundnut pods yields kg of seeds. Generally groundnut seeds can be stored at 1-5 C and 50-70% relative humidity for 1 year without loss of quality. Groundnut seeds tend to absorb gases and off-flavours, which should be avoided. Oil is extracted from groundnut seed by expeller pressing, hydraulic pressing, solvent extraction, or a combination of these methods. Expeller pressing is most widely used. Genetic resources The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India, holds the largest collection of groundnut types, with more than 15,000 accessions, differing for many vegetative, reproductive, physiological and

25 ARACHIS 27 biochemical traits including their reactions to biotic and abiotic stresses. A duplicate sample is maintained in a regional gene bank at Niamey, Niger. Other large collections of groundnut germplasm are held in the United States (Southern Regional Plant Introduction Station, Griffin, Georgia, 9000 accessions), India (National Research Centre for Groundnut (NRCG), Junagadh, 8000 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, 5400 accessions; Institute of Oil Crops Research, Wuhan, 5700 accessions). In tropical Africa substantial groundnut germplasm collections are held in Senegal (Centre National de Recherche Agronomique, Bambey, 900 accessions), Uganda (Serere Agricultural and Animal Production Research Institute, Serere, 900 accessions) and Malawi (Plant Genetic Resources Centre, Chitedze Agricultural Research Station, Lilongwe, 500 accessions). The ARC Grain Crops Institute in Potchefstroom, South Africa, has a collection of 850 accessions. Core collections that have been developed are useful for developing models for future germplasm acquisition and evaluation for disease resistance. Additional collections are needed for most groundnut-producing regions, as landraces in these areas are rapidly being replaced with modern cultivars. Breeding Groundnut breeding efforts greatly increased when the ICRISAT groundnut breeding programme was established in Diverse breeding populations are now being tested in regional programmes in sub-saharan Africa and Asia. Most breeding programmes are conducted by public institutions. Groundnut breeding objectives have concentrated on adaptation to regional markets and production systems. All programmes aim at improving the productivity of the crop and resistance to diseases. Large-scale efforts to evaluate wild Arachis germplasm have resulted in identification of useful sources of resistance to many diseases. Recently there have been initiatives to improve flavour and quality. Breeding for resistance to aflatoxin contamination has received increased attention, and the selection of short-duration cultivars with drought resistance is a high priority in many programmes. Commonly used breeding methods in groundnut are pedigree selection, bulk-pedigree selection and single-seed descent. Backcross breeding has not been used extensively as most of the economically important traits of groundnut are quantitatively inherited. The major constraints to rapid genetic enhancement include: the close linkage of disease resistance genes with loci conferring undesirable pod and seed characteristics; the later maturity, lower partitioning to seeds, and higher photoperiodsensitivity of disease-resistant germplasm compared to agronomically elite susceptible materials; the large genotype x environment interactions for traits of economic importance; and limited gene introgression from wild Arachis species to cultivated groundnut. Genetic linkage maps of groundnut have been constructed using various markers, but the saturation level is insufficient for routine application in molecular breeding. An efficient tissue culture and transformation system for groundnut has been developed and transgenic groundnut plants have been produced using biolistic and Agrobacterium-meAiateA methods. Prospects Groundnut remains an extremely useful crop, providing food, oil, fodder and fuel to households and is also an important source of additional income as a cash crop. Important problems in groundnut cultivation in tropical Africa are low yields and its susceptibility to diseases. Many cultivars are still susceptible to early and late leaf spot and rust, as resistance tends to be linked with long duration and undesirable pod and seed characteristics. Therefore, the development of high-yielding cultivars with resistance to disease (especially leaf spots and rust) and adaptation to African production systems remains a major challenge for groundnut breeders. The application of DNA markers may allow breeders to combine resistance to biotic and abiotic stresses with improved productivity and seed quality. The use of biotechnology tools will become increasingly important for large-scale germplasm characterization and resolving some of the constraints (e.g. disease problems) in groundnut production. Major references Dwivedi et al., 2003; Knauft & Ozias-Akins, 1995; Knauft & Wynne, 1995; Kokalis-Burelle et al. (Editors), 1997; Krapovickas & Gregory, 1994; Melouk & Shokes (Editors), 1995; Shorter & Patanothai, 1989; Smartt (Editor), 1994; Stalker, 1997; Wynne, Beute & Nigam, Other references Burkill, 1995; Clavel, 2002; Clavel & Gautreau, 1997; de Waele & Swanevelder, 2001; Gillett et al., 1971; ILDIS, 2005; Isleib & Wynne, 1992; Kochert et al., 1996; Lynch & Mack, 1995; McDonald et al., 1998; Neuwinger, 2000; Norden, Smith & Corbet, 1982; Popelka, Terryn & Higgins, 2004; Purseglove, 1968; Sherwood et al., 1995; Singh, 1995; Singh & Nigam, 1997; Steinman, 1996;

26 28 CEREALS AND PULSES USDA, 2004; Wynne & Gregory, Sources of illustration Shorter & Patanothai, Authors B.R. Ntare AVENAABYSSINICA Höchst. Protologue Schimp, iter Abyss, sectio III No 1877 (1844). Family Poaceae (Gramineae) Chromosome number 2n = 28 Vernacular names Ethiopian oat, Abyssinian oat (En). Avoine d'abyssinie (Fr). Origin and geographic distribution Avena abyssinica probably originated from Avena barbata Pott ex Link. It is native to Eritrea, Ethiopia and Yemen, and is cultivated for its grain in northern Ethiopia. It has been tried as a crop in Tanzania and Algeria. Uses In Ethiopia the grain of Avena abyssinica is used mixed with barley to make pancake-like bread ('injera'), local beer ('tella') and other products. The grain is also eaten roasted as a snack ('kollo'). Malt containing an admixture of Avena abyssinica has been credited with giving better beer than malt from pure barley or wheat. Botany Erect annual grass up to 1.5 m tall. Leaves alternate, simple; leaf sheath long and loose; ligule acute, membranous; blade linear, flat, usually glaucous. Inflorescence a terminal panicle cm long, loose and open, the branches slightly rough. Spikelet slenderstalked, pendulous, cm long, 2-3- flowered, with the uppermost floret reduced or vestigial, non-shattering; glumes almost equal, narrowly elliptical, sharply acuminate, severalveined; lemma cm long, smooth and glabrous or with a few bristly hairs near the awn insertion or margin, narrowly bifid, each lobe with 1 vein extended into an apical bristle 1 3 mm long, usually also minutely toothed at the base of the bristle, with slender, abruptly bent awn cm long, arising from the back of the lemma; palea almost as long as lemma, bifid, 2- keeled, prickly hairy on the back; stamens 3; ovary superior, villous, with 2 stigmas. Fruit a caryopsis (grain). Avena comprises about 30 species, which are diploid (2n - 14), tetraploid (2n 28) or hexaploid (2n 42). The tetraploid Avena abyssinica belongs to section Ethiopica. It can be distinguished from the common oat (Avena sativa L.) by the presence of two bristles at its lemma tip. It crosses easily with the weed Avena vaviloviana (Malzev) Mordv., resulting in weedy hybrid swarms which shatter easily. Ecology Avena abyssinica is cultivated, but is also a weed of arable land, particularly in barley and wheat fields. In Ethiopia it is found at m altitude. Experiments indicate that Avena abyssinica is a long-day plant and that vernalization results in earlier flowering. Management Avena abyssinica is recorded to be grown sometimes in Eritrea and Ethiopia, but it is unclear to what extent this is still the case. As a weed in barley and wheat it is often tolerated and harvested with the main crop. Avena abyssinica is affected by crown rust or leaf rust (Puccinia coronata f.sp. avenae). It is also susceptible to infestation with ergot (Claviceps spp.); consumption of infected grains has led to outbreaks of ergotism in Ethiopia. Genetic resources and breeding The largest germplasm collections of Avena abyssinica are kept at in the United States (USDA-ARS National Small Grains Germplasm Research Facility, Aberdeen, Idaho, 241 accessions), the United Kingdom (John Innes Centre, Department of Applied Genetics, Norwich, 65 accessions) and the Russian Federation (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 53 accessions). No germplasm collections are known to exist in tropical Africa. Prospects Avena abyssinica is a semidomesticated plant in Ethiopia, where it is used as a component in mixtures for the preparation of food and local beer. It has, however, not become important and its present status is uncertain. Major references Baum, 1977; Fröman & Persson, 1974; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; National Research Council, 1996; Phillips, Other references Clayton, 1970; Engels, Hawkes & Worede (Editors), 1991; Harlan, 1989a; Harlan, 1989b; rung, 1979; Martens & McKenzie, 1973; Sampson & Burrows, 1972; Welch (Editor), Authors M. Brink AVENASATIVA L. Protologue Sp. pi. 1: 79 (1753). Family Poaceae (Gramineae) Chromosome number 2n = 42 Vernacular names Oat, oats, common oat (En). Avoine, avoine cultivée (Fr). Aveia, aveia-

27 AVENA 29 amarela (Po). Origin and geographic distribution Avena sativa is only known in cultivation and its exact origin is unclear. Oat was not cultivated as early as wheat and barley and probably it persisted as a weed in fields of these cereals for centuries before it was taken into cultivation. Oat seeds have been found in 4000-year-old remains in Egypt, but these were probably from weeds and not from cultivated oat. The oldest known cultivated oat remains were found in caves in Switzerland that date back to around 1000 BC. Avena sativa probably evolved in central or northern Europe from wild Avena sterilis L. germplasm from southwestern Asia. Nowadays oat is extensively cultivated in northern temperate regions, mainly in Europe and North America. In tropical Africa it is mainly grown in Ethiopia and Kenya. It is also cultivated in South Africa, Morocco, Algeria and Tunisia. Uses Oat has been used as food and fodder since ancient times. Oat grain is an ingredient in a wide range of food products including breakfast cereals, porridge, cookies, breads and muffins, crackers and snacks, beverages, meat extenders and baby foods. Oat grain is considered to have potential as a source of good edible oil. In Ethiopia oat is made into 'injera' (pancake-like bread), 'tella' (local beer) and other products. In industrialized countries oat grain mainly finds application as animal feed, especially for horses, but also for cattle, sheep, turkeys and other animals. The green plant is good forage; it makes good hay and silage or is grazed by animals. The straw too is used as forage, e.g. in Ethiopia, where it also serves as bedding for livestock, fuel and roofing material Avena sativa - planted for traditional houses. Also in Kenya oat is used as food and as fodder. A field sown for grain production can be used for grazing if rains are inadequate; on the other hand fields are sometimes grazed to delay grain development. In Australia oat is planted for sand binding on dunes. An important industrial utilization is the use of oat hulls for the production of furfural and other furan compounds, utilized in the production of fungicides, disinfectants and preservatives. Oat products also find application in the cosmetic industry as talc replacements and in skin care products. Oat flour has anti-oxidant properties and has been used for food conservation, but it has largely been replaced by synthetic chemicals. Production and international trade According to FAO statistics the average world oat grain production in amounted to about 25.9 million t/year from 12.7 million ha. The main producing countries are the Russian Federation (5.8 million t/year in , from 3.8 million ha), Canada (3.3 million t/year from 1.4 million ha) and the United States (2.0 million t/year from 0.9 million ha). The average oat grain production in sub-sahara Africa in has been estimated at 55,000 t/year from 53,000 ha, almost entirely from Ethiopia (50,000 t/year from 49,000 ha) and Kenya (3500 t/year from 3400 ha) and small amounts from Zimbabwe. Due to the decline of oat as animal feed, partly as a result of the mechanization of agriculture and decreased importance of workhorses, world production steadily declined from about 50 million t/year (from about 35 million ha) in the early 1960s to about 26 million t/year (from about 13 million ha) in the early 2000s. In the same period the production in sub-sahara Africa increased from about 20,000 t/year to about 55,000 t/year. The largest part of the oat production is consumed locally, with about 2.5 million t/year entering international trade in Canada (1.2 million t/year), Sweden (450,000 t/year) and Finland (360,000 t/year) are the largest exporters; the United States (1.7 million t/year) the largest importer. International trade in oat in tropical Africa is insignificant. Properties The composition of oat grain per 100 g edible portion is: water 8.2 g, energy 1628 kj (389 kcal), protein 16.9 g, fat 6.9 g, carbohydrate 66.3 g, dietary fibre 10.6 g, Ca 54 mg, Mg 177 mg, P 523 mg, Fe 4.7 mg, Zn 4.0 mg, vitamin A 0 IU, thiamin 0.76 mg, ribofla-

28 30 CEREALS AND PULSES vin 0.14 mg, niacin 0.96 mg, vitamin B mg, folate 56 ig and ascorbic acid 0 mg. The essential amino acid composition per 100 g edible portion is: tryptophan 234 mg, lysine 701 mg, methionine 312 mg, phenylalanine 895 mg, threonine 575 mg, valine 937 mg, leucine 1284 mg and isoleucine 694 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 2424 mg, oleic acid 2165 mg, palmitic acid 1034 mg and linolenic acid 111 mg (USDA, 2004). Compared to other cereals, oat has a high protein content and a good amino acid profile, with a high level of lysine. The fat content is also higher than that of other cereals, with a high proportion of unsaturated fatty acids. Starch contents of 43-61% have been recorded. The amylose content of the starch is 11-34%. Starch granules are irregular to polygonal in shape with an average diameter of (3.8-) (-10.5) urn. The soluble fibre in oat bran is believed to reduce blood cholesterol in humans, due to the presence of ß-glucan. Oat has shown hypoglycaemic activity and beneficial effects on gastrointestinal functions. Oat bran seems to protect against dental caries. Compounds contributing to the antioxidant properties of oat flour include glyceryl esters of hydroxycinnamic acid, ferulic acid and caffeic acids. Oat seems to be tolerated by most coeliac patients, although concerns remain. The unhulled ground grain is highly acceptable for ruminants and horses. Hulled and ground oat grain is usually fed to pigs and poultry. Oat green forage, hay and silage is highly palatable to ruminants. In Kenya the crude protein content of oat plants (on dry matter basis) declined from 20.2% for 50 cm-tall plants to 8.1% at full flowering, with the in-vitro protein digestibility declining from 84.9% to 46.7%. The crude fibre content increased from 23.3% to 28.1%, the carbohydrate content from 42.0% to 56.0%, the ash content decreased from 11.5% to 5.4%, and the ether-extract from 3.7% to 2.4%. Straw in Kenya contained on dry matter basis: 5.3% crude protein, 38.0% crude fibre, 10.2% ash, 1.4% ether extract and 45.1% N-free extract. Description Erect annual grass up to 2 m tall, with a fibrous root system; stems (culms) solitary or tufted, smooth or scabrous beneath the inflorescence. Leaves alternate, simple; leaf sheath long and loose, rounded on the back; ligule blunt, membranous, 3-5 mm long; blade linear, flat, cm x (-2) cm. Inflorescence a terminal panicle 15 30( 40) cm long, loose and open or contracted. Spikelet Avena sativa - 1, part of stem with leaf; 2, inflorescence. Redrawn and adapted by Iskak Syamsudin slender-stalked, pendulous, cm long, usually 2-3-flowered, with the uppermost florets reduced, non-shattering; glumes almost equal, narrowly elliptical-oblong, sharply acute, several-veined; lemma cm long, more or less truncate or minutely 2-4-toothed, awn present or absent, glabrous or sparsely hairy around the awn insertion; palea slightly shorter than lemma; stamens 3; ovary superior, villous, with 2 laterally exserted stigmas. Fruit a caryopsis (grain), cm long, narrow, with nearly parallel sides, hairy, grooved lengthwise on the face, tightly enclosed by lemma and palea. Other botanical information Avena comprises about 30 species, which are diploid (2n = 14), tetraploid (2ra- 28) or hexaploid (2n = 42). All hexaploid Avena species belong to section Avena. The hexaploids Avena sativa, Avena byzantina C.Koch (red oat), Avena fatua L. and Avena sterilis L. are interfertile. Avena byzantina is closely related to Avena sativa and possibly derived through selection from the latter. Some authors include Avena byzantina in Avena sativa. Avena byzantina is cultivated mainly in southern Europe. In tropical Africa it has been grown experimentally in Kenya and

29 AVENA 31 has been recorded as a weed in Tanzania. It has naturalized in South Africa, where it is found in disturbed locations and on roadsides. Avena fatua and Avena sterilis are important weeds of cereals, e.g. in Europe, Ethiopia and Kenya, and differ from Avena sativa in their shattering spikelets and hairy lemmas. The tetraploid Avena abyssinica Höchst, can be distinguished from Avena sativa by the two bristles at its lemma tip. Avena sativa is variable, which is reflected in elaborate infraspecific classifications, mainly based on inflorescence and lemma characteristics. Growth and development Oat seeds start to germinate 7 days after sowing. Seedlings start tillering days after sowing. Up to 12 leaves are produced per stem. The time from sowing to flowering depends on sowing time, e.g. in north-western Europe it is 100 days for spring-sown crops to 270 days for autumnsown crops. Oat is largely self-pollinated with up to 1% outcrossing. The time from flowering to harvesting is about 60 days in north-western Europe. The total crop duration is 3 6 months in Ethiopia and Kenya, and 6-11 months in temperate regions. Shattered seeds remain viable in the soil for a long time, which may result in weedy growth in subsequent crops. Ecology Oat is mostly grown under cool and moist conditions in cool-temperate regions, mainly as spring-sown and to some extent autumn-sown crop. In tropical Africa it is mostly grown in mid- to high-altitude areas ( m altitude), with an annual rainfall over 800 mm and minimum and maximum air temperatures of 6 C and 24 C, respectively. In Ethiopia it is usually grown at m altitude. Oat is not as sensitive to frost as wheat. When moisture is not limiting it also performs well in warmer, humid mid-altitude tropical environments. Oat needs more water than any other cereal except rice. It is generally a quantitative long-day plant, but differences in photoperiod-sensitivity exist among cultivars, with particularly strong responses in northern European cultivars. Vernalization responses have also been recorded. Oat thrives on a wide range of soil types, as long as drainage is sufficient. It grows on soils that are sandy, low in fertility, or highly acidic (as low as ph 4.5), but it performs best on welldrained, fertile, loamy soils. Propagation and planting Oat is propagated by seed. The 1000-seed weight is g. Seeds 2-3 months old normally have more than 85% germination. Oat seeds kept under natural cold conditions in the highlands of Ethiopia still germinated after 15 years of storage. Under tropical highland conditions, the seeds are broadcast or drilled (row spacing cm) at a recommended rate of kg/ha, with drilled crops and crops intended for grain production at the lower end of the range. In Kenya oat is normally sown with a wheat drill in rows cm apart, at a seed rate of kg/ha. In the high-altitude tropics, oat is usually sown at the onset of the rainy season. When grown for forage, oat is sometimes grown mixed with vetches {Vicia spp.) or pea (Pisum sativum L.). Management The vigorous growth of oat seedlings and the release of allelopathic compounds depress weed growth. Hand-weeding (usually once) and application of broadleaf herbicides such as 2,4-D may be used for weed control. In Ethiopia farmers do not weed their oat fields. Oat fields are seldom fertilized in tropical Africa, although the crop responds well to application of NPK. In the Ethiopian highlands the general recommendation is to apply kg N and kg P per ha at sowing, and kg N per ha top-dressing at tillering. Oat is grown in rotation with barley, wheat, faba bean, pea and sometimes with fallow or a green manure. Allelopathic compounds can hinder the growth of subsequent crops, if they are sown within about 3 weeks after the harvest of oat. In Kenya an oat crop may be grazed 1 2 times, before it is allowed to mature as a grain crop. Alternatives are 2 4 grazings of a crop in a season, 2 grazings followed by use as a hay crop, or 1 2 grazings followed by a hay crop and a grazing. Oat can be grazed within 6 8 weeks after sowing. Diseases and pests Leaf (crown) rust (Puccinia coronata f.sp. avenae) and stem rust (Puccinia graminis f.sp. avenae) are the most important diseases of oat. Systemic fungicides such as triazoles and morpholines are effective in controlling them, but this is seldom economical. The use of cultivars resistant to rust is recommended. Septoria leaf spot (Septoria avenae), barley yellow dwarf virus (BYDV, also called 'red leaf), halo blight (Pseudomonas coronafaciens), loose smut (Ustilago avenae) and covered smut (Ustilago hordei) are other common diseases of oat. Major pests include grasshoppers, army worms and cut worms. Various aphid species are vectors of BYDV. At later stages of maturity birds and rats are important pests. Weevils (Sitophi-

30 32 CEREALS AND PULSES lus granarius) and some other beetles attack stored oat grain. Harvesting In Africa oat is harvested manually by sickle or scythe, for forage normally after heading, and for grain when the seed is in the hard dough stage, which is normally at the end of the rainy season. The harvest is left in the field for sun-drying and is subsequently threshed (grain crop) or piled (forage crop). A mechanized combine can be utilized for harvesting large-scale grain oat crops or a mower for forage oat crops. When oat straw is needed for roofing, the panicle is harvested by sickle for grain, after which the remaining stubble is harvested by sickle or scythe at ground level. Yield The world average grain yield of oat is about 2 t/ha with straw yields of about 5.5 t/ha. As the result of threshing is not a naked grain, the hull (lemma and palea) generally accounts for 25 35%of the total grain weight. The average oat grain yield in Ethiopia and Kenya is about 1 t/ha. When oat is harvested for green fodder, hay or silage the dry matter yield is 4-15 t/ha. Handling after harvest Oat grain should be dried to a moisture content of 12 14% before storage, with a storage temperature below 20 C. In industrialized countries oat grain processing generally involves cleaning, drying (to partially inactivate lipolytic enzymes which would result in rancidity), hulling, cutting, steaming (to complete inactivation of lipolytic enzymes) and flaking or milling. The cheapest way of conserving oat forage is hay making. In areas where hay making is difficult, oat can be made into silage, either alone or mixed with legumes. Genetic resources Large Avena sativa germplasm collections are maintained in the United States (National Small Grains Germplasm Research Facility, USDA-ARS, Aberdeen, Idaho, 10,000 accessions), the Russian Federation (N.I. Vavilov Ail-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 8800 accessions), Canada (Soil and Crops Research and Development Centre, Sainte-Foy, Quebec, 7500 accessions) and Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 3700 accessions). A total of 656 accessions are kept at ICARDA (Syria) and ILRI (Ethiopia). About 835 oat accessions (mostly from Europe, United States and Ethiopia) are available at the EARO (Ethiopian Agricultural Research Organization) Holetta Research Centre in Ethiopia. Oat seeds show orthodox seed storage behaviour. Breeding The major objectives in oat breeding are improved grain and forage yields. The development of cultivars resistant to fungal and viral diseases, especially crown and stem rusts, is important too. Sources of resistance to crown rust are found in wild Avena species, especially Avena sterilis. Modern techniques of breeding have resulted in improved cultivars with desirable traits such as resistance to diseases, high yield, huskless ('naked') grains, white-coloured large grain, and high contents of protein and oil in the grain. Molecular marker maps have been constructed and a genetic transformation system has been developed that allows the insertion of foreign genes into oat using particle bombardment. In tropical Africa there are small-scale breeding activities in Ethiopia and Kenya, mainly focusing on resistance to diseases and increased forage and grain yields. In Ethiopia and Kenya farmers are mainly interested in dual-purpose cultivars. Prospects Due to its tolerance to poor soil fertility and to frost, its low requirements of external inputs such as fertilizers, and its dualpurpose character (food and fodder), oat has favourable prospects in the highlands of tropical Africa, especially for resource-poor farmers. On a worldwide scale, oat also has potential for pharmaceutical and cosmetic uses. Major references Assefa et al., 2003; Baum, 1977; Boonman, 1993; Coffman (Editor), 1961; Coffman, 1977; McMullen, 2000; Phillips, 1995; Suttie, 2004; Thomas, 1995; Welch (Editor), Other references Clayton, 1970; Dougall, 1954; Feyissa, 2004; Frey, 1998; Fröman & Persson, 1974; Gebrehiwot, 1981; Gibbs Russell et al., 1990; Gibson & Benson, 2002; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hoover et al, 2003; Jellen & Beard, 2000; Jutzi & Grysels, 1984; Kassam et al, 1991; Mailu, 1997; Mulat & Damesa, 1996; Peltonen-Sainio, 1998; Rogerson, 1956; USDA, 2004; Wight et al, 2003; Zhou, Jellen & Murphy, Sources of illustration Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hegi, Authors G. Assefa

31 BAUHINIA 33 BAUHINIA PETERSIANA Bolle Protologue Peters, Naturw. Reise Mossambique 6(1): 24 (1861). Family Caesalpiniaceae (Leguminosae - Caesalpinioideae) Chromosome number 2n = 28 Synonyms Bauhinia macrantha Oliv. (1871). Vernacular names Kalahari white bauhinia, wild coffee bean, coffee neat's foot, camel's foot (En). Bauhinia blanc du Kalahari (Fr). Chingando (Po). Origin and geographic distribution Bauhinia petersiana occurs in south-eastern DR Congo and Tanzania, and throughout southern Africa. Uses The meal of pounded seeds of Bauhinia petersiana is eaten. The seeds are also eaten as nuts after roasting and are considered a delicacy in parts of Botswana. Roasted and ground seeds are used as a substitute for coffee. Unripe seeds can also be eaten. The pods are eaten either roasted (Namibia) or boiled (Zambia). Seed oil is extracted in Botswana for local use. In DR Congo the bark fibres are used to make rope and the roots to produce a dye. Bauhinia petersiana is widely browsed by livestock. In Zimbabwe, South Africa and the United States it is grown as an ornamental shrub. In much of its area of distribution the leaves of Bauhinia petersiana are boiled, the steam inhaled and the cooled-down liquid drunk to cure common cough. The Shona people of Zimbabwe take an infusion of the roots to treat dysmenorrhoea and female infertility. In South Africa the pounded leaves mixed with salt are boiled and the warm liquid is sprinkled on wounds to promote healing. A decoction of the macerated roots is drunk as a remedy for diarrhoea. Properties Dry seeds of Bauhinia petersiana contain per 100 g: water 6.8 g, energy 1554 kj (371 kcal), protein 22.9 g, fat 13.1 g, carbohydrate 40.2 g, fibre 13.0 g, Ca 237 mg, P 317 mg, Fe 3.9 mg, thiamin 0.58 mg, riboflavin 0.2 mg and niacin 1.6 mg (Arnold, Wells & Wehmeyer, 1985). The principal fatty acids in the seed oil are linoleic acid (45%), oleic acid (26%), palmitic acid (16%) and stearic acid (7%). The roots and leaves contain tannins. Botany Shrub or small tree up to 10 m tall; young branchlets pubescent and with many small orange glands or scales, some branchlets coiled apically, tendril-like. Leaves alternate, simple; stipules 3-5 mm x 1-2 mm, deciduous; petiole cm long; blade 2-8 cm x 2-10 cm, 2-lobed to one-third to two-thirds down, lobes elliptical to ovate or rounded. Inflorescence an axillary, leaf-opposed or terminal raceme,1 10-flowered. Flowers bisexual, almost regular, 5-merous; hypanthium (1.5-)2-5.5(-6.5) cm long; sepals linear to linear-lanceolate, cm long; petals narrowly elliptical to ovate, cm x cm, white throughout or sometimes base of midrib pink; fertile stamens (4-) 5(-6), slightly unequal in length, staminodes 4-5; ovary superior, slender, hairy, style 2-4 cm long. Fruit a linear-oblong to oblanceolateoblong pod cm x cm, woody, dehiscent, 5-6-seeded. Seeds 1-3 cm x cm, deep chestnut-brown to blackish. Bauhinia is a widespread tropical genus with about 250 species. In Bauhinia petersiana 2 subspecies are distinguished. Subsp. petersiana has 2 10-flowered inflorescences, appressed hairs at the lower side of the leaves, and it is distributed in the more eastern and northern parts of the area of the species. Subsp. macrantha (Oliv.) Brummitt & J.H.Ross has l-3(-4)- flowered inflorescences and curved or spreading hairs at the lower side of the leaves, and it is found from southern Zambia and western Zimbabwe towards the south and west. Bauhinia petersiana does not possess root nodules and relies on soil nitrogen. Ecology Bauhinia petersiana is found in open grassland, wooded grassland and woodland. In East Africa it is found at altitudes of m. In southern Africa it is found in dry localities, e.g. in the Kalahari with an annual rainfall of about 350 mm only, and it tolerates frost. Management In the Kalahari the seeds of Bauhinia petersiana are harvested from April to July. For use as an ornamental Bauhinia petersiana is propagated by seed, cuttings or layering. The 100-seed weight is about 670 g. Genetic resources and breeding There are indications that Bauhinia petersiana has disappeared completely from communal grazing land in southern Botswana, possibly as a result of increased grazing pressure. Two accessions from Botswana are stored in the Millenium Seedbank (Ardingly, West Sussex, United Kingdom), a single accession from Zimbabwe is kept by the Desert Legume Programme in the United States. Prospects Although Bauhinia petersiana has been considered a candidate for cultivation as a food crop for a long time, no attempts have been made to domesticate the species, nor to exploit or even explore its genetic variation.

32 34 CEREALS AND PULSES Efforts to conserve the southern populations, in situ or ex situ, are urgently needed to avoid loss of variation. Major references Arnold, Wells & Wehmeyer, 1985; Coates Palgrave, 1983; Gelfand et al., 1985; Leger, 1997; von Koenen, Other references Brenan, 1967; Brummitt & Ross, 1982; Dakora, Lawlor & Sibuga, 1999; Ketshajwang, Holmback & Yeboah, 1998; National Academy of Sciences, 1979; Neuwinger, 2000; Ross, 1977; Story, 1958; van Wyk & Gericke, 2000; Watt & Breyer-Brandwijk, Authors C.H. Bosch BRACHIARIA DEFLEXA (Schumach.) C.E.Hubb. ex Robyns Protologue Bull. Jard. Bot. Etat. 9(3): 181 (1932). Family Poaceae (Gramineae) Chromosome number 2n = 18, 36 Synonyms Pseudobrachiaria deflexa (Schumach.) Launert (1970). Vernacular names Guinea millet, animal fonio, false signal grass (En). Fonio à grosses graines, gros fonio, millet de Guinée, kolo rassé (Fr). Jégé (Po). Origin and geographic distribution Guinea millet is a semi-domesticated weed of the African savanna. It is found from Cape Verde and Senegal eastward to Ethiopia, Eritrea and Somalia and southward to South Africa; it also occurs in western Asia to Pakistan and India. Uses Guinea millet is considered to belong to the 'kreb' grasses, a group of grasses occurring in the Sahel region and collected for human consumption, especially in time of food shortage. In the Fouta Djallon Highlands on the Guinea-Mali border the grain of a cultivated type is ground into flour used to make cakes and fritters. Guinea grass provides excellent forage. Properties Guinea millet has soft grains that are easily ground into flour. Botany Annual grass up to 70(-100) cm tall; stems (culms) solitary or tufted, slender, often weak and ascending. Leaves alternate, simple and entire; leaf sheath pale, striate, finely pubescent; ligule ciliate; blade broadly linear to narrowly lanceolate, 4-25 cm x cm, velvety pubescent. Inflorescence panicle-like, composed of 5-15 racemes borne on an axis 6-15 cm long; racemes distant, widely spreading, 2-10 cm long, often with side-branches, bearing mostly paired distant spikelets. Spikelet up to 15 mm long stalked, broadly elliptical, mm long, glabrous to pubescent, acute, 2- flowered with lower floret male or sterile and upper bisexual; lower glume up to half as long as spikelet, upper glume as long as spikelet, membranous, 7-veined; lemma of lower floret membranous, lemma of upper floret wrinkled and acute; palea of upper floret obtuse to acute; stamens 3; ovary superior, with 2 stigmas. Fruit a caryopsis (grain), ellipsoid, compressed. Brachiaria comprises about 100 species distributed in the tropics and subtropics, mainly in the Old World. It has been proposed that Brachiaria be nearly completely reduced to Urochloa. Brachiaria deflexa is usually easily distinguishable from other Brachiaria species by its panicle-like inflorescence, which resembles that of Panicum spp. It intergrades with Brachiaria ramosa (L.) Stapf and is sometimes included in the latter. Guinea millet is often confused with fonio (Digitaria exilis (Kippist) Stapf). Compared to fonio, it has larger grains and it grows faster, but it requires higher soil fertility and better drainage. The cultivated type sown in the Fouta Djallon Highlands (called var. sativa Portères) differs from the wild types harvested elsewhere particularly by being totally glabrous and by having a branched stem and much larger grains; furthermore, it is non-shattering. Some Guinea millet types mature in as little as days, but most types take days to reach maturity. Guinea millet follows the C4- cycle photosynthetic pathway. Ecology Guinea millet is found from sealevel up to 1500 m altitude in open woodland, forest margins and as a weed of cultivated land and disturbed soils, often preferring slightly shady locations. It is considered droughtresistant. Brachiaria deflexa needs fertile and well-drained soils for optimum growth. Management Guinea millet is mostly collected from the wild, but farmers sometimes encourage its invasion into cereal fields and it is sown as a cereal in the Fouta Djallon Highlands. Farmers also sometimes sow fastmaturing Guinea millet types to fill in gaps in a field sown with fonio, sorghum, maize or other cereals. Genetic resources and breeding Guinea millet collections are held at CIAT (Centro Internacional de Agricultura Tropical, Cali, Colombia, 16 accessions) and in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, Kikuyu, Muguga, 5 accessions). In view of its wide distribution, Guinea

33 CAJANUS 35 millet seems not threatened by genetic erosion. The Guinea millet cultivar sown in the Fouta Djallon Highlands may have potential for further selection. Prospects Too little is known about Guinea millet to make an accurate assessment of its potential as a food plant. More information is needed on its nutritional properties, agronomy, ecological requirements and genetic diversity. The wild type will remain a valuable fodder plant for dry regions, due to its drought resistance and excellent fodder characteristics. Major references Burkill, 1994; Clayton & Renvoize, 1982; Gibbs Russell et al., 1990; National Research Council, 1996; Portères, Other references Basappa, Muniyamma & Chinnappa, 1987; Baudet, 1981; Clayton, 1972; Clayton, 1989; Cope, 1995; de Wet, 1995c; Froman & Persson, 1974; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Phillips, 1995; van der Hoek & Jansen, 1996a. Authors M. Brink CAJANUS CAJAN (L.) Millsp. Protologue Publ. Field Columbian Mus., Bot. Ser. 2(1): 53 (1900). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceace) Chromosome number In 22 Synonyms Cajanus indicus Spreng. (1826). Vernacular names Pigeon pea, Congo pea, red gram (En). Pois cajan, pois d'angole, ambrevade (Fr). Ervilha do Congo, feijào guandu, ervilha de Angola (Po). Mbaazi (Sw). Origin and geographic distribution Pigeon pea originated in India, where it has been grown for thousands of years. It reached Africa about 2000 BC or earlier, and a secondary centre of diversity developed in East Africa. With the conquests and slave trade it reached the Americas probably via both the Atlantic and the Pacific. Nowadays it is grown all over the tropics, but is most important in the Indian subcontinent and East Africa. It is not known in the wild, but often occurs naturalized as an escape from cultivation. Uses In Africa dry pigeon pea seeds are often used for sauces accompanying staple food preparations such as cassava, yam and rice. Ripe seeds are eaten fried or boiled, often after being soaked first, or boiled into porridge. In the Indian subcontinent pigeon pea is mainly used as a pulse, in the form of 'dhal' (soaked, Cajanus cajan - planted dried, hulled and split seeds), and this use is carried on by Indian communities in Africa. The use of immature pigeon pea seeds and pods as a vegetable in soups and sauces is common in many African countries. Canning and freezing of the green seed is mainly done in Central America. In Asia pigeon pea may be used instead of soya bean to make tempeh or tofu. Vegetative parts are excellent fodder and seeds are also used as animal feed. The by-products of dhal production (seed coat and broken cotyledons) are used as cattle and poultry feed in India, and also in Kenya and Malawi. Pigeon pea is useful in hedges and windbreaks on dry soils and in agroforestry (e.g. in alley cropping systems, where it is pruned to supply green manure). It is also grown as a shade crop, cover crop, or as support for vanilla. Pigeon pea improves the soil through its extensive root system, nitrogen fixation and the mulch provided by the fallen leaves. It serves as a host for silkworm (Madagascar) and the lac insect. Stems and branches, especially those of medium- and long-duration cultivars, are used for basketry, thatching, fencing and as fuel. In Nigeria the stems serve as stakes for yam. Pigeon pea finds wide application in traditional medicine. Diarrhoea, gonorrhoea, measles, burns, eye infections, earache, sore throat, sore gums, toothache, anaemia, intestinal worms, dizziness and epilepsy are treated with leaf preparations. Root preparations are taken to treat cough, stomach problems and syphilis. Stem ash is applied on wounds, and stalks and roots are chewed against toothache. Powdered seeds serve as a poultice on swellings. In

34 36 CEREALS AND PULSES Madagascar the leaves are used to clean teeth. Production and international trade According to FAO statistics the world pigeon pea production in amounted to 3.1 million t/year from 4.3 million ha; the main producing country is India (2.5 million t from 3.4 million ha). The main producers in tropical Africa in were Malawi (79,000 t from 123,000 ha), Uganda (78,000 t from 78,000 ha), Kenya (59,000 t from 152,000 ha) and Tanzania (47,000 t from 66,000 ha). The annual production in Mozambique is estimated at 40,000 t. Worldwide the area under pigeon pea has increased steadily from about 2.8 million ha in the early 1960s to about 4.3 million ha at present, whereas the production increased from million t to around 3 million t in the same period. Pigeon pea is mostly consumed locally, with limited amounts entering international trade, and trade statistics are hardly available. Occasional export demand may boost cultivation. In Malawi and Kenya an estimated 65% of the pigeon pea production in was consumed on-farm, 10% traded on the domestic market, and 25% exported. For Tanzania these amounts were 35%, 10% and 55%, respectively. By far the most important export market is India, followed by the Middle East. In the Indian market African pigeon pea has to compete mainly with pigeon pea from Myanmar and pea from Canada and France. Pigeon pea is widely, but often informally, traded within Africa, for instance between Mozambique and Malawi and between Tanzania and Kenya. In northern Tanzania most of the pigeon pea produced is sold in Kenya, where it is very popular among the Indian community. Properties The composition of raw mature pigeon pea seeds per 100 g edible portion is: water 10.6 g, energy 1435 kj (343 kcal), protein 21.7 g, fat 1.5 g, carbohydrate 62.8 g, dietary fibre 15.0 g, Ca 130 mg, Mg 183 mg, P 367 mg, Fe 5.2 mg, Zn 2.8 mg, vitamin A 28 IU, thiamin 0.64 mg, riboflavin 0.19 mg, niacin 3.0 mg, vitamin Ik 0.28 mg, folate 456 Jg and ascorbic acid 0 mg. The essential amino acid composition per 100 g edible portion is: tryptophan 212 mg, lysine 1521 mg, methionine 243 mg, phenylalanine 1858 mg, threonine 767 mg, valine 937 mg, leucine 1549 mg and isoleucine 785 mg. The principal fatty acids per 100 g edible portion are: linoleic acid 778 mg and palmitic acid 307 mg (USDA, 2004). Methionine is the limiting amino acid, followed by tryptophan and threonine. Antinutritional factors in Nigerian pigeon pea seed include trypsin inhibitor activity, tannins and phytate. The composition of raw immature seeds per 100 g edible portion is: water 65.9 g, energy 569 kj (136 kcal), protein 7.2 g, fat 1.6 g, carbohydrate 23.9 g, dietary fibre 5.1 g, Ca 42 mg, Mg 68 mg, P 127 mg, Fe 1.6 mg, Zn 1.0 mg, vitamin A 67 IU, thiamin 0.40 mg, riboflavin 0.17 mg, niacin 2.2 mg, folate 173 Jg and ascorbic acid 39 mg (USDA, 2004). The leaves contain 15-24% crude protein. Extracts of pigeon pea seeds have shown antisickling action on red blood cells. This activity has been related to the presence of phenylalanine and hydroxybenzoic acid; related compounds have an even more pronounced effect. Description Erect shrub or subshrub, but regularly grown as an annual, up to 4 m tall, with roots up to 2 m deep; stem erect, ribbed, up to 15 cm in diameter; branches many, slender. Leaves alternate, 3-foliolate; stipules linear, 2-4 mm long; petiole (l-)1.5-6(-8) cm long, grooved above; rachis cm long, slightly winged; stipels filiform, 1-4 mm long; petiolules 1-4 mm long; leaflets elliptical to lanceolate, cm x cm, acute, covered with small yellow glands, green above, Cajanus cajan - 1, part of flowering and fruiting branch; 2, seed. Redrawn and adapted by Achmad Satiri Nurhaman

35 CAJANUS 37 silvery grey-green beneath. Inflorescence an axillary false raceme cm long; peduncle up to 8 cm long; bracts deciduous, ovate, c. 8 mm x 5 mm, acute. Flowers bisexual, papilionaceous; pedicel cm long; calyx campanulate, yellowish velvety and glandular, tube (3-)4-5(-6) mm long, lobes 3-5(-7) mm long; corolla yellow or cream, standard almost round, mm in diameter, dorsally yellowred, orange or purple, wings obovate, mm x 6 7 mm, yellow, clawed, keel petals mm x 5-7 mm, yellow-green, clawed; stamens 10, 9 fused and 1 free; ovary superior, 1- celled, sessile, style curved. Fruit a straight or sickle-shaped pod 2-10(-13) cm x (0.5-)l-1.5 cm, hairy, glandular-punctate, splitting into 2 spiralling valves, septate between the seeds, (2-)4 9-seeded. Seeds globose to ellipsoid or squarish, 4 9 mm x 3-8 mm x 3-6 mm, white, cream, brown, purplish to almost black, plain or mottled. Seedling with hypogeal germination; first leaves simple. Other botanical information Cajanus comprises 34 species. Two wild Cajanus species are known in Africa: Cajanus kerstingii Harms from West Africa, and Cajanus scarabaeoides (L.) Thouars occurring along the coasts of Africa and Madagascar, and at some locations more inland. The former does not cross with Cajanus cajan, but the latter can produce hybrids with it; spontaneous hybrids are known but rare. Although the use of Cajanus kerstingii as human food and animal feed seems not recorded, it could be of value in ways similar to pigeon pea. In Senegal the branches of Cajanus kerstingii are used for making temporary hut walls. Other relatives of pigeon pea are found in Asia and Australia. In India 10 maturity groups are distinguished in pigeon pea, usually combined into four categories: extra early, early, medium and latematuring cultivars (120, 145, 185, more than 200 days after sowing, respectively). Growth and development Pigeon pea seeds germinate at temperatures of C, but most rapidly at C. Emergence is complete 2-3 weeks after sowing. Vegetative development starts slowly, but after 2-3 months growth accelerates. Flowering (of 50% of the plants) starts days after sowing; seed maturity normally ranges from days. In humid areas, flowering and fruiting may continue throughout the year. The flower structure of pigeon pea favours self-pollination, but up to 82% out-crossing has been recorded, depending on the presence and activity of pollinating insects. Pigeon pea roots are nodulated and fix nitrogen in association with Bradyrhizobium and Rhizobium strains. Ecology Pigeon pea is grown in the tropics and subtropics between 30 N and 30 S latitudes. Optimum average temperatures range from C; frost is not tolerated. Above 29 C, soil moisture and fertility may be limiting. The optimum annual rainfall is mm, but pigeon pea is tolerant to drought and can be grown in areas with less than 600 mm rainfall. It also grows in regions with an annual rainfall of over 2500 mm. Flowering is accelerated by short days; there are very few truly day-neutral types. In Africa pigeon pea is grown at altitudes up to 2000(-2400) m. It can be grown on a wide range of soil types, but waterlogging is harmful. Drained soils of intermediate water-holding capacity and with ph 5-7 are favourable. A soil salinity of 6-12 ds/m is tolerated by many cultivars. Propagation and planting Pigeon pea is propagated by seed. Stem cuttings rarely succeed. Longevity of seeds depends on storage conditions; in gene banks at low temperature and moisture the seed survives for decades. The 1000-seed weight is g; in Africa large-seeded cultivars are the commonest. Planting arrangements vary widely, and seeds may be broadcast or sown in rows with plant spacings of cm x cm. Seedlings are difficult to transplant. In Africa and India pigeon pea is often grown in intercropping systems, usually with cereals, but also with cassava and cotton. It fits well in intercropping systems because its slow initial growth reduces competition for the associated crop and its late maturity spreads labour requirements at harvest time. After harvest of the intercrop, longduration pigeon pea continues to grow and to produce seed and to protect the soil. Pigeon pea performs well when grown in single rows alternating with 2 rows of cereals (e.g. sorghum, millets), cotton or groundnut. In Uganda and Mauritius, it is generally planted as a restorative crop towards the end of a rotation cycle. In vitro cultures have been initiated successfully from different tissue sources, including leaves, shoots and roots, and organogenesis as well as somatic embryogenesis is possible. Regenerated plants have also been obtained via callus and by direct differentiation from leaves. Management As a field crop, pigeon pea may be typified as rather primitive; the tall genotypes in particular are quite cumbersome in cultivation. Weed control is necessary be-

36 38 CEREALS AND PULSES cause of the slow initial growth. Response to fertilizers is rarely economic; a phosphate dressing is generally recommended at kg/ha. In tropical Africa fertilizer application to pigeon pea is not common. Residual nitrogen after a crop of pigeon pea can be about 40 kg/ha. In India the nutrient uptake of a pigeon pea crop yielding 1.2 t seeds and 6.3 t straw per ha has been calculated as 85 kg N, 8 kg P, 16 kg K, 23 kg Ca, 15 kg Mg, 9 kg S, 38 g Zn, 31 g Cu, 128 g Mn and 1440 g Fe per ha. Wind may bend the plants but staking is not practised. Irrigation as a lifesaver can be economic; in intensive cropping of short-duration cultivars, irrigation may be required. Pigeon pea is also grown as a ratoon crop, e.g. in Central and East Africa. For fast regrowth, the pruning height should not be lower than 50 cm. Part of the shoots may be removed to reduce competition. Diseases and pests The most important fungal diseases of pigeon pea in tropical Africa are leaf spot (Mycovellosiella cajani, synonym: Cercospora cajani), Fusarium wilt (Fusarium udum) and powdery mildew (Leveillula taurica). Leaf spot is not important in drier areas, but can cause serious losses in humid regions. It can be controlled by periodic sprays of fungicides such as benomyl and mancozeb and by the use of disease-free seed and the selection of fields away from perennial pigeon pea, which may act as a source of inoculum. Pigeon pea lines with resistance to leaf spot have been identified. Recommended control measures a- gainst seed-borne and soil-borne Fusarium wilt are intercropping and crop rotation with cereals, fallow, removal of diseased plants, seed treatment with fungicides, and the use of disease-free seed and fields, but the best strategy is the use of resistant cultivars. Moderately resistant lines in all maturity groups are available. Fusarium wilt is generally more severe in ratoon crops, from the second year onwards. Suggested control measures against powdery mildew include the use of fungicides and the selection of fields not near perennial pigeon pea; resistant lines have been identified. Pigeon pea sterility mosaic virus (PPSMV) is the most important disease of pigeon pea in India, but it appears to be restricted to Asia. Pigeon pea is susceptible to root-knot nematodes (Meloidogyne spp.) and reniform nematodes (Rotylenchus spp.). Resistant lines have been identified in India. Insect pests are important in all pigeon peagrowing areas. The most important ones are pod-sucking bugs (mainly Clavigralla spp.), pod borers (including Helicoverpa armigera and Maruca vitrata, synonym: Maruca testulalis) and the pigeon pea pod fly (Melanagromyza chalcosoma). The use of insecticides is recommended, but chemical control is cumbersome and expensive in tall indeterminate forms. Pigeon pea lines have been recorded with resistance to either or both Helicoverpa armigera and Melanagromyza chalcosoma, and to Maruca vitrata, but resistance has not been incorporated into cultivars that are acceptable to farmers with respect to taste, seed colour and size. Integrated pest management (IPM), comprising the judicious application of insecticides, the use of tolerant or resistant cultivars, agronomic practices (planting date) and biological control with natural enemies, is receiving attention. Because of its long flowering period, damage by pests such as Helicoverpa armigera and other borers, and Agromyza fruit flies, may be compensated for by new flushes. Bruchids (Callosobruchus spp.) are important pests of pigeon pea, infecting pods in the field as well as stored seeds. Seed storage in clean bins and in the form of split seeds reduces bruchid attack. Other control measures include sundrying, treatment with insecticides and storage in admixture with ash and various plant products, such as tobacco and neem (Azadirachta indica A.Juss.) extracts or leaves. Harvesting Immature pigeon pea pods are picked over a long period of time in home gardens or hedge crops, as is usual in Africa. For ripe seeds the crop is usually cut near the ground when most pods are mature; many leaves are still green at that stage. Alternatively, the ripe pods are picked from the standing crop, sometimes in several rounds as the crop often matures unevenly. Mechanical harvesting of ripe pods is possible with combineharvesters, but only for short-statured cultivars maturing uniformly with pods at a uniform level above the soil. Yield In Africa pigeon pea seed yield averages around 600 kg/ha with traditional landraces in mixed intercropping. For Uganda 1000 kg/ha has been recorded. Under optimum conditions in sole cropping, yields of more than 5000 kg/ha are possible. Low yields may be partly due to the fact that a considerable part of the seeds is harvested and eaten before maturity. Forage yields range from 3 8 t/ha, but in experiments 50 t/ha have been obtained. Fuel yields are usually 7-10 t/ha, but yields up to 30 t/ha have been recorded.

37 CAJANUS 39 Handling after harvest Entire air-dried pigeon pea plants are threshed, usually by hand or with cattle, and seed is cleaned. Shelled fresh peas are sold on markets as a vegetable. Processing includes dhal-making, either wet, after sprinkling heaps of seed, or dry, by milling. Genetic resources The world pigeon pea germplasm collection covers India and several African countries, and some Caribbean islands. More than 13,000 samples of Cajanus cajan are available in the collection of the International Crops Research Institute for the Semi- Arid Tropics (ICRISAT, Patancheru, India), and various breeders and institutes have parts of this collection. Some 18 wild Cajanus species and at least 39 other species of the subtribe Cajaninae are represented. Related perennial species are regularly rejuvenated in ICRISAT's Botanical Garden. Attempts are continuing to cover all taxa and areas of occurrence. In tropical Africa the National Genebank of Kenya in Kikuyu has a collection of more than 1200 accessions of pigeon pea. Pigeon pea has orthodox seed storage behaviour. Breeding Pigeon pea breeding work started in India in the early 20 th century, and mainly involved the selection of more productive and early-maturing landraces. Concerted international pigeon pea improvement work began in the 1970s at the International Institute of Tropical Agriculture (UTA), where shortstatured cultivars of determinate growth habit were developed. Within the Consultative Group on International Agricultural Research (CGIAR) system, ICRISAT now has the mandate for pigeon pea improvement. So far, national breeding programmes in Africa have mainly relied on ICRISAT lines and selections from local landraces, but some countries (e.g. Kenya, Uganda and Rwanda) have developed their own crossing programmes. Breeding of pigeon pea for high yield, and for consumer and miller preference are prime criteria. Stability of yield may be obtained by selecting for photoperiod insensitivity, disease and pest resistance, and suitability for intercropping and multiple harvests. Improved genotypes are now available for most of these characteristics. Resistance is available in wild relatives and there are promising pestresistant and disease-resistant types. Because out-crossing is frequent, traditional methods for self-pollinated crops, such as pedigree breeding, have not been very effective. Selection is further complicated by large genotype x environment interaction. Genetic male sterility is available in Cajanus cajanifolius (Haines) Maesen and is now used in hybrid breeding programmes. However, the production costs of hybrid seeds are high, and a search is going on for cytoplasmic male sterility. Short-duration Indian cultivars include 'Prabhat', 'T21', 'UPAS- 120'; medium-duration cultivars are 'C 11', 'BDN- 1', 'Pusa Ageti', 'Sharda' and several 'ICP' lines developed by ICRISAT. Hybrid cultivars are also available. Improved cultivars in Kenya include 'NPP 670', 'KAT 60/8' (both developed in Kenya) and 'ICPL 87091'. However, they are more susceptible to insect pests than the local landraces, due to their determinate growth habit and the fact that they start flowering when pest populations are high. Furthermore, the seeds of 'KAT 60/8' and 'ICPL 87091' are relatively small, making them less wanted on the local markets than the larger seeds from landraces. The Fusarium wilt-resistant cultivar TCP 9145', derived from a landrace collected in Kenya by ICRISAT, has been successfully released in Malawi. 'ICPL 87' and 'ICPL 146' lines are recommended as sole-cropping, multiple-harvest cultivars for Tanzania, Malawi and Zimbabwe. The transfer of insect resistance (from Cajanus scarabaeoides (L.) Thouars), high protein content (several species), improved drought resistance (Cajanus acutifolius (Benth.) Maesen), soil salinity tolerance (Cajanus albicans (Wight & Arn.) Maesen) or annual behaviour (Cajanus platycarpus (Benth.) Maesen) has not yet materialized. Insect-tolerant lines have been identified, however. Transgenic pigeon pea plants, expressing a cowpea protease inhibitor gene or a protective antigen of the Rinderpest virus, have been obtained using Agrobacterium-medi&ted gene transfer or bombardment with micro-particles. Prospects As a multi-purpose crop pigeon pea is well known but ought to be promoted especially in more semi-arid regions, for which the crop is well suited due to its tolerance to drought and low soil fertility and its ability to recover after environmental or biotic stress. Its large seed-yield potential offers promise in more favourable environments. Pigeon pea fits well in agro-forestry, in smallholder garden cropping and in hedge cultivation, and is suitable for improved short-duration fallows. It also fits in more intensive systems. Shortduration, photoperiod-insensitive, short-statured cultivars of determinate growth habit with fast growth and elevated harvest index

38 40 CEREALS AND PULSES may be the ideotype to aim for. In the export market (mainly India) African pigeon pea faces strong competition and higher productivity; more efficient marketing arrangements are necessary to remain competitive in this market. Major references Hillocks et al., 2000; lo Monaco, 2003; Nene, Hall & Sheila, 1990; Reddy, Raju & Lenné, 1998; Silim, Mergeai & Kimani (Editors), 2001; Silim, Tuwafe & Singh (Editors), 1994; Singh et al., 2001; van der Maesen, 1985; van der Maesen, 1989a; Whiteman, Byth & Wallis, Other references Akojie & Fung, 1992; Aulakh et al., 1985; Berhaut, 1976; du Puy et al., 2002; Ene-Obong, 1995; Gillett et al, 1971; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Joshi et al., 2001; Kay, 1979; Mackinder et al., 2001; Mergeai et al., 2001; Neuwinger, 2000; Polhill, 1990; Popelka, Terryn & Higgins, 2004; Remanandan & Singh, 1997; Tabo et al., 1995; Thulin, 1989a; USDA, 2004; van der Maesen, 2003; Westphal, Sources of illustration Busson, Authors L.J.G. van der Maesen CENCHRUS BIFLORUS Roxb. Protologue FL ind. 1: 238 (1820). Family Poaceae (Gramineae) Chromosome number n = 15, 16, 17, 18, 24 Vernacular names Cram-cram, Indian sandbur (En). Cram-cram (Fr). Origin and geographic distribution Cenchrus biflorus is found throughout tropical Africa, extending eastwards through Arabia and Iran to Pakistan and India. It has been introduced elsewhere, e.g. in North America and Australia. Uses The grain of Cenchrus biflorus is edible and highly nutritious. People in areas of marginal subsistence regularly collect the seed; elsewhere it is considered a famine food. In the Sahel it is collected as a wild cereal, e.g. by the Tuareg people. The grains are pounded and eaten raw, made into porridge, or mixed and cooked with other foods. The grain is also made into a drink. In Sudan a thin bread ('kisra') is made from the grain and in Mauritania the ground grains are made into cakes. The grain of Cenchrus biflorus is also a famine food in India, where it is eaten raw or used, mixed with pearl millet, to make bread. In normal years it is mixed with sugar and 'ghee', and eaten as a children's food. Cenchrus biflorus is considered a valuable forage grass in the Sahel; it is mainly browsed in the juvenile stage and when the grains have fallen off. It can be cut several times during the rainy season and made into hay or silage. The spiny involucres are sufficiently softened by ensiling to make consumption of the whole plant possible. Cenchrus biflorus persists until the end of the dry season and thus is important as a reliable source of fodder. Also in India the plant is used as a fodder and it is sown against desertification; in northern Australia it is sown as a forage. The leaves are eaten during famine in the Thar desert in India. The root of Cenchrus biflorus is an ingredient of traditional aphrodisiac prescriptions. Properties The composition of hulled grains of Cenchrus biflorus per 100 g is: water 9.8 g, energy 1549 kj (370 kcal), protein 17.8 g, fat 8.5 g, carbohydrate 62.3 g, Ca 144 mg, P 270 mg and Fe 22 mg (Leung, Busson & Jardin, 1968). The essential amino-acid composition per 100 g hulled grain is: lysine 214 mg, methionine 393 mg, phenylalanine 926 mg, threonine 658 mg, valine 1052 mg, leucine 2745 mg and isoleucine 892 mg (FAO, 1970). The protein and fat contents are high compared to other cereals. Cenchrus biflorus plants in the Sahel contain crude protein 10.0%, crude fibre 34.6%, crude fat 1.5%, nitrogen-free extracts 42.8%, P 0.35%, K 4.18%, Ca 0.28%, Mg 0.21% and Na 0.01%. In spite of its usefulness, Cenchrus biflorus is often considered a noxious weed; the spiny inflorescences may injure humans and livestock and cause infection. Botany Loosely tufted, annual grass, with ascending stems (culms) up to 1 m tall. Leaves alternate, simple and entire; ligule a line of hairs; blade linear, flat, 2-25(-35) cm x 2-7(- 10) mm, apex filiform. Inflorescence a spikelike panicle 2-15 cm x 9-12 mm, with 1-3 spikelets enclosed by an involucre of prickly bristles; rachis angular, sinuous; involucre ovoid, 4-11 mm long with numerous spines, inner spines erect, fused at base, retrorsely hairy on the pungent, recurving apex, outer spines shorter, spreading. Spikelet lanceolate mm long, acute, consisting of 2 glumes and usually 2 florets; glumes shorter than spikelet; lower floret male or sterile, its lemma as long as spikelet, membranous, upper floret bisexual, its lemma as long as spikelet, thinly leathery; stamens 3, ovary superior, glabrous, with 2 hairy stigmas. Fruit a dorsally compressed caryopsis (grain), mm x 1.5-2

39 CENCHRUS 41 Cenchrus comprises about 20 species in tropical and warm temperate regions, mainly in Africa and the Americas. It is closely related to Pennisetum, which differs in non-spiny inner involucral bristles free to the base. The spiny spikelets of Cenchrus biflorus adhere to hairs of animals and clothes, making possible wide dispersal. Cenchrus biflorus follows the C4-cycle photosynthetic pathway. Ecology Cenchrus biflorus is mostly found in semi-arid and arid regions with an annual rainfall of mm, up to 1300 m altitude, usually on dry sandy soils and in cultivated, overgrazed or otherwise disturbed areas. It is extremely abundant in the Sahel and southern Sahara, where it may form massive stands. A study in western Niger showed that it had become much more abundant and dominant in the late 1980s than it was in the early 1960s. Management Cenchrus biflorus can be propagated by seed. The optimum temperature for seed germination is 35 C. In tropical Africa the grains are collected from the wild. The spiny spikelets shatter easily at maturity and are often allowed to fall, after which they are swept into piles with a bunch of straw, or they are raked with a big 'comb' with a handle. The plants may be beaten with a stick if not all spikelets have fallen. The spikelets are pounded in a mortar and the grains are separated by winnowing. In the Lake Chad area the inflorescences are cut off with a knife, after which the grains are dried, threshed and winnowed. In Kordofan (Sudan) the grains are hulled by rubbing them between two pieces of leather. Genetic resources and breeding The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, holds 10 accessions of Cenchrus biflorus. In view of its wide distribution and abundance, Cenchrus biflorus is certainly not threatened by genetic erosion. Prospects Cenchrus biflorus yields a highly nutritious grain, with unusually high protein and fat contents. Formerly it was important as a wild cereal, but nowadays it seems to play a role in human nutrition in times of shortage only. As a forage it has remained important, especially because of its persistence throughout the dry season. Cenchrus biflorus is unlikely to become more important in the future, mainly due to its spiny spikelets which adhere to clothes and cause injuries to humans and animals, and result in the plant often being considered a noxious weed. Major references Burkill, 1994; Clayton & Renvoize, 1982; Naegele, 1977; National Research Council, 1996; Phillips, Other references Bartha, 1970; Batello, Marzot & Touré, 2004; Bhandari, 1974; Bouwman, 1979; Clayton, 1989; Cope, 1995; FAO, 1970; Harlan, 1989b; Leung, Busson & Jardin, 1968; Peyre de Fabrègues, Authors M. Brink CENCHRUS PRIEUEII (Kunth) Maire Protologue Bull. Mus. natn. Hist, nat., Paris, sér. 2, 3: 523 (1931). Family Poaceae (Gramineae) Chromosome number 2n - 34 Origin and geographic distribution Cenchrus prieurii is distributed from Mauritania and Senegal through the Sahel zone to Ethiopia; it also occurs in Arabia, Pakistan and northern India. Uses The grain of Cenchrus prieurii is an important food for some desert nomads; it serves as a famine food in Africa and India. The crushed or ground grain is made into porridge. In India the grains are eaten raw and are used, mixed with pearl millet, for making bread. Cenchrus prieurii is valued for grazing; it also makes suitable hay and silage. It persists until the endof the dry season and thus is important as a reliable source of fodder. In northern Nigeria Cenchrus prieurii is planted as a forage. Properties The fodder value of Cenchrus prieurii plants in the Sahel is: crude protein 9.2%, crude fibre 37.1%, crude fat 1.8%, nitrogen-free extractives 42.8%, P 0.15%, K 3.36%, Ca 0.23%, Mg 0.19% and Na 0.02%. Information on the nutrititional characteristics of the grain is not available. Botany Loosely tufted, annual grass, with stems (culms) up to 80 cm tall. Leaves alternate, simple and entire; ligule a line of hairs; blade linear, flat, cm x mm, finely acute. Inflorescence a cylindrical spikelike panicle 5-12 cm x 2-4 cm, with 1-2 spikelets enclosed by an involucre of long bristles; rachis angular, scabrid, sinuous; involucre with many slender scabrid bristles mm long and furnished with spines directed upwards, far exceeding the spikelet, fused at base. Spikelet lanceolate, 4-5 mm long, acute, consisting of 2 glumes and usually 2 florets; glumes shorter than spikelet; lower floret male or sterile, its lemma as long as spikelet, mem-

40 42 CEREALS AND PULSES branous; upper floret bisexual, its lemma as long as spikelet, thinly leathery. Fruit a dorsally compressed caryopsis (grain). Cenchrus comprises about 20 species in tropical and warm temperate regions, mainly in Africa and the Americas. It is closely related to Pennisetum, which differs in non-spiny inner involucral bristles free to the base. Cenchrus prieurii follows the C4-cycle photosynthetic pathway. Ecology Cenchrus prieurii is found in semiarid and arid regions with an average annual rainfall of mm, in open sandy locations up to 1000 m altitude. A study in western Niger showed that Cenchrus prieurii had become much more abundant and dominant in the late 1980s than it was in the early 1960s. Management Cenchrus prieurii is collected from the wild. The 1000-seed weight is 0.2 g. Genetic resources and breeding A few accessions of Cenchrus prieurii are held in Australia (Australian Tropical Crops & Forages Genetic Resources Centre, Biloela, Queensland, 3 accessions) and the United Kingdom (Welsh Plant Breeding Station, Institute of Grassland and Environmental Research, Aberystwyth, Wales, 2 accessions). In view of its wide distribution, Cenchrus prieurii is not threatened by genetic erosion. Prospects Cenchrus prieurii has some value as a source of food in times of scarcity and as a fodder grass, but it is unlikely to increase in importance in the future. Investigations are necessary to find out if the nutritional quality of the grain of Cenchrus prieurii is as high as that of the grain of Cenchrus biflorus Roxb. Major references Bogdan, 1977; Burkill, 1994; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Peyre de Fabrègues, 1992; Phillips, Other references Bartha, 1970; Breman & de Ridder, 1991; Clayton, 1972; Freedman, undated. Authors M. Brink ClCERARIETINUM L. Protologue Sp. pi. 2: 738 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceace) Chromosome number 2n = 16 Vernacular names Chickpea, Bengal gram, gram, garbanzo (En). Pois chiche (Fr). Grâo de bico, gravanço, ervanço (Po). Mdengu (Sw). Origin and geographic distribution Chick- Cicer arietinum -planted pea is not known in a wild state. Its origin is believed to be in south-eastern Turkey and adjoining Syria and Iran. The earliest remains of chickpea seeds date back to around 7000 BC (Syria and Turkey). Chickpea was gradually introduced to the western Mediterranean region, to eastern and southern Asia and East Africa. It reached the Indian subcontinent before 2000 BC. Chickpea cultivation is expanding where it has been recently introduced, e.g. in Australia, New Zealand, the United States and Canada. In tropical Africa it is mainly cultivated in East Africa (Sudan, Eritrea, Ethiopia, Kenya, Tanzania) and in Malawi; it is grown particularly in areas with a marked cool season. Lesotho and South Africa have recently introduced chickpea at experimental level. Chickpea is found semi-naturalized as an escape, e.g. in Tanzania. Uses Chickpea is primarily grown for its mature seeds, which are used as human food. These are consumed alone or together with cereals as a side dish in the form of a sauce or soup. In Ethiopia sauces ('wot') made of ground seeds ('shiro') and split seeds ('kik') are commonly eaten with 'injera' (unleavened, pancake-like bread). Chickpea is also an ingredient of weaning foods. The immature seeds are consumed fresh, or roasted and salted as snacks. In India the whole dried seeds are eaten boiled or made into dhal, prepared by splitting the seed and separating the husk. In Mediterranean countries, chickpea is eaten whole in salads, or in stews, and flour mixed with sesame paste yields the well-known appetizer 'hummus'. Canned chickpea seeds are popular in the United States and in Europe.

41 ClCER 43 In India young chickpea sprouts are eaten as a vegetable. Broken seeds and residues from dhal production are used as feed, the straw serves as fodder and dried stems and roots are used as fuel for cooking. Chickpea starch is suitable for textile sizing, giving a light finish to silk, wool and cotton clothes, and can also be used in the manufacturing of plywood. An indigo-like dye is obtained from chickpea leaves. Production and international trade According to FAO statistics, the annual world production and harvested area of chickpea from 1961 to 2003 has remained relatively stable at around 7 million t and 10 million ha, respectively. The production in amounted to 7.9 million t per year from 10.3 million ha. The main producing countries were India (4.1 million t per year from 6.3 million ha), Turkey (600,000 t from 600,000 ha), Pakistan (500,000 t from 1.1 million ha), Canada (250,000 t from 200,000 ha), Mexico (250,000 t from 150,000 ha) and Australia (200,000 t from 200,000 ha). The annual production in sub-saharan Africa was about 280,000 t from 430,000 ha, the main producers being Ethiopia (168,000 t from 191,000 ha), Malawi (35,000 t from 88,000 ha), Sudan (25,000 t from 13,000 ha), Tanzania (25,000 t from 63,000 ha) and Kenya (20,000 t from 55,000 ha). In tropical Africa the area and production of chickpea have been increasing recently, whereas they are declining in northern Africa. The decline in Ethiopia was arrested and has been reversed due to the release of improved cultivars, liberalized markets and intensive extension activities. In Zambia chickpea is grown by commercial farmers around urban areas. The world trade in chickpea steadily increased from 100, ,000 t per year in the 1970s to about 700,000 t per year in The main exporters in were Australia (192,000 t per year), Mexico (155,000 t), Turkey (114,000 t), Canada (85,000 t) and Iran (75,000 t). Ethiopia exported about 50,000 t in 2002, but insignificant amounts in Tanzania exported about 20,000 t in 2002 and less than 10,000 t per year in The main importers in this period were India (183,000 t per year), Pakistan (98,000 t), Spain (57,000 t), Algeria (43,000 t) and Bangladesh (40,000 t). Imports into sub-saharan Africa were very low. Properties The composition of mature raw chickpea seeds per 100 g edible portion is: water 11.5 g, energy 1525 kj (364 kcal), protein 19.3 g, fat 6.0 g, carbohydrate 60.7 g, dietary fibre 17.4 g, Ca 105 mg, Mg 115 mg, P 366 mg, Fe 6.2 mg, Zn 3.4 mg, vitamin A 67 IU, thiamin 0.48 mg, riboflavin 0.21 mg, niacin 1.5 mg, vitamin Be 0.54 mg, folate 557 (ig and ascorbic acid 4.0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 185 mg, lysine 1291 mg, methionine 253 mg, phenylalanine 1034 mg, threonine 716 mg, valine 809 mg, leucine 1374 mg and isoleucine 828 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 2593 mg, oleic acid 1346 mg, palmitic acid 501 mg, linolenic acid 101 mg and stearic acid 85 mg (USDA, 2004). The protein content of chickpeas is lower than that of most other pulses, but this is compensated for by the higher protein digestibility. Antinutritional factors include trypsin inhibitors, haemagglutinins, tannins and oligosaccharides. Adulterations and substitutes In India chickpea is sometimes adulterated with the cheaper, but potentially toxic, grass pea (Lathyrus sativus L.). Description Spreading to erect, annual herb up to 100 cm tall; stem simple or Cicer arietinum branch; 2, seed. Source: PROSEA 1, flowering and fruiting

42 44 CEREALS AND PULSES branched from the base; taproot reaching 1-2 m depth, secondary roots mostly spreading in the top cm soil layer. Leaves alternate, imparipinnate, with (7 )11 15( 17) leaflets; stipules 2 5-fid, ovate to triangular, 3-5 mm x 2-4 mm; rachis cm long, grooved above; leaflets sessile, ovate to elliptical, 5-20 mm x 2-15 mm, the upper two-thirds of the margins sharply toothed, glandular pubescent on both sides. Inflorescence reduced to a single axillary flower; peduncle 3-20(-37) mm long; bracts 1-3, linear to triangular, up to 3 mm long. Flowers bisexual, papilionaceous; pedicel 3-12 mm long, recurved at fruiting; calyx campanulate, tube 3 4 mm long, teeth lanceolate, 4 5 mm long, with prominent midribs; corolla white, pink, purplish or blue, standard obovate, 8-10 mm x 7 10( 17) mm, with a broad claw, wings obovate, 6-9 mm x c. 4 mm, auriculate, keel6 8 mm x c. 3 mm with a 2 3 mm long claw; stamens 10, 9 united for 4-5 mm and 1 free, anthers basi-dorsifixed; ovary superior, sessile, ovate, 2 3 mm x mm, 1-celled, style incurved, 3-4 mm long, stigma small. Fruit an inflated rhomboid-ellipsoid pod mm x 8-20 mm, densely glandular pubescent, 1 2(-4)- seeded. Seeds globular to angular obovoid, 5 14 mm x 4-10 mm, with a median groove and a conspicuous beak overhanging the hilum, creamy to brown, green or black, surface smooth or wrinkled. Seedling with hypogeal germination; the first two leaves scale-like. Other botanical information Cicer comprises 43 species, 9 annual and 34 perennial. The wild Cicer species most closely related to Cicer arietinum are the annuals Cicer reticulatum Ladiz. and Cicer echinospermum P.H. Davis. Cicer reticulatum, a rare species from Turkey, is sometimes regarded as a subspecies of Cicer arietinum; it is morphologically, biochemically and karyologically very similar and completely cross-compatible. Fertile hybrids have also been produced in crosses of chickpea and Cicer echinospermum, though fertility barriers do exist. Other related species are Cicer bijugum Rech.f., Cicer chorassanicum (Bunge) Popov, Cicer cuneatum Höchst, ex A.Rich., Cicer Judaicum Boiss., Cicer pinnatifidum Jaub. & Spach, Cicer yamashitae Kitam. (all annuals) and Cicer anatolicum Alef. (a perennial), and some of these have been used for crossing with cultivated chickpea. Within cultivated chickpea 2 main groups are commonly discerned: the large-seeded, creamcoloured Kabuli types and the small-seeded, darker-coloured, smooth or wrinkled Desi types. Some intermediate cultivars also exist. Desi-type chickpeas are bushy plants with relatively small leaflets and flowers, purplish anthocyanin pigments in their stems and blueviolet flowers, and are primarily grown in southern Asia and Ethiopia. The Kabuli types have erect growth and white flowers and are grown in the Mediterranean region. Cultivars of the Kabuli type cook faster and have less dietary fibre than those of the Desi type. Seed colour is an important characteristic of chickpea, determining its quality and acceptance in many countries. In East Africa brown Desi chickpeas are most popular. Growth and development Seedlings normally emerge 7 15 days after sowing. Flowering starts after days. Chickpea is selfpollinated, with less than 2% out-crossing. The crop duration is normally 3-6 months, but chickpea is indeterminate by nature and may continue to grow as long as moisture is not limiting. The deep, strong taproot serves as a water-storage organ for the growing plants, extending growth into the dry season. Chickpea is effectively nodulated by Mesorhizobium ciceri and Mesorhizobium mediterraneum. Ecology Chickpea is cultivated in tropical, subtropical and warm temperate zones. Its production is concentrated in the cool, dry season of the semi-arid tropics. It grows from sealevel to over 2500 m altitude, but it is not suitable for the humid and hot lowland tropics, where it often fails to flower. In East Africa it is grown at m altitude, in areas with an annual rainfall of mm and an average temperature of C during the growing period. Under these conditions the crop takes days to mature. It performs well when planted during the rainy season provided that the field is well drained, but humidity favours the development of aseochyta blight. Rain during flowering hampers seed set. The drought tolerance varies from moderate to considerable. Chickpea is generally a quantitative long-day plant. Soils need to be well drained, with ph 5-7 or more. Salinity is hardly tolerated, if at all. Soils vary from sandy to sandy loam and black cotton soils. In Ethiopia and Kenya chickpea is mainly grown towards the end of the rainy season on black cotton soils with declining soil moisture. Propagation and planting Chickpea is propagated by seed. Seed can be stored for 4 5 years at a temperature of 4 C. The 1000-seed weight varies widely, from 20 g for some Desi types, to more than 600 g for the larger Kabuli

43 ClCER 45 types. Seed does not show dormancy. Because of the large variation in seed size, seed rates may range from kg/ha for small-seeded cultivars to kg/ha for large-seeded ones. In East Africa the seeds are broadcast and then ploughed under by animal-drawn ploughs. In southern Asia spacings of cm between rows and cm between plants in a row are common. Chickpea is grown as a sole crop or in intercropping with linseed, sorghum or other crops. It is often sown as a relay crop, e.g. in rice paddies. Management Chickpea is very sensitive to weed competition, especially in the first 4-6 weeks after sowing. Weed control is usually by mechanical methods. The weed population can be high if the crop receives late rains after sowing and in that case immediate weeding is required. The use of P-fertilizer high in S is recommended, but normally no inorganic fertilizers are applied. Some farmers in Sudan apply 100 kg diammonium phosphate (DAP) per ha. In Sudan and in India chickpea is sometimes grown under irrigation. In Ethiopia chickpea is grown in rotation with cereals, mainly tef (Eragrostis te/(zuccagni) Trotter); in India it is also grown in rotation with cereals, including pearl millet, sorghum, wheat, barley and rice. Diseases and pests The most important chickpea disease worldwide is ascochyta blight caused by the seed-borne Ascochyta rabiei, but this disease is of lesser importance in Ethiopia, except when chickpea is sown early in the rainy season. Important diseases in Ethiopia, Sudan and Eritrea are fusarium wilt caused by Fusarium oxysporum f.sp. ciceris, dry root rot caused by Macrophomina phaseolina (Rhizoctonia bataticola), and collar rot caused by Sclerotium rolfsii. Control measures against the seed- and soil-borne fusarium wilt include the use of seed from disease-free plants, seed treatment with fungicides, and the use of resistant cultivars. Crop rotation is not effective, because the fungus survives in the soil for long periods. Control measures for dry root rot and collar rot include the use of disease-free seed, the removal of crop residues and the elimination of weed hosts. Effective control with crop rotation is difficult, because both pathogens have a wide host range. Resistance to Macrophomina phaseolina has been observed, but the disease may affect even resistant cultivars if these are grown in infected soil for a long period. Root-knot nematode (Meloidogyne javanica) is an important parasite of chickpea. Pod borer (Helicouerpa armigera) and cutworm (Agrotis ipsilon) are common insect pests on chickpea in East Africa and India. Insecticides such as endosulfan are recommended for the control of these insects. Integrated Pest Management (IPM) practices, including tolerant cultivars, pest population monitoring, bio-pesticides and natural enemies, have been developed to reduce the reliance on insecticides. Callosobruchus spp. are important storage insects in chickpea. Harvesting Mature seeds are harvested when the pod tips of the uppermost branch of the plant turn yellow. Harvesting is done manually by pulling the plants, after which they are sun-dried in the field. Where chickpea is machine-harvested, a tall and erect plant type is preferred. Yield The average yield of chickpea is less than 1 t/ha in sub-saharan Africa, except under irrigation in Sudan, where average yields up to 1.9 t/ha are obtained. In the Central Highlands of Ethiopia, farmers harvest over 2 t/ha due to a favourable growing environment, while research shows a potential yield up to 5.5 t/ha in this area. The average yield of chickpea in India is also less than 1 t/ha. Handling after harvest When the harvested pods have been sun-dried to a moisture content of 12 13%, they are taken to the threshing ground. In Ethiopia, Eritrea and Sudan, threshing is done by trampling using draught animals. Small harvests are threshed by beating with sticks. Seeds are separated from the chaff by winnowing. The cleaned seeds are kept in stores or taken to the market. Bruchid attack makes storage for more than 6 months difficult. Ethiopian farmers mix chickpea with tef to keep the seeds for a longer period. Seed for planting may be protected with Pyrethrine insecticides. Genetic resources ICRISAT (Patancheru, India) has a collection of about 17,000 chickpea accessions, from which a representative core collection of 1956 accessions has been formed. Other large collections are kept by ICARDA (Aleppo, Syria, about 10,000 accessions) and in Australia (Australian Temperate Field Crops Collection, Horsham, 7700 accessions) and the United States (USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, 4400 accessions). ICRISAT and ICARDA have 58 and 268 accessions of wild Cicer species, respectively. Many species from Central Asia are not yet represented in the collections. In Ethiopia, which is considered a secondary

44 46 CEREALS AND PULSES centre of diversity for chickpea, the Institute of Biodiversity Conservation has the largest collection (of about 1000 accessions) in Africa. Chickpea shows orthodox seed storage behaviour and can be stored for long periods without loss of viability. For long-term storage a temperature of-20 C is used. Breeding Genetic improvement of chickpea aims at higher yield and resistance to diseases, insects and other stresses such as drought, waterlogging and cold. Sources of resistance/tolerance have been identified for diseases (including ascochyta blight, fusarium wilt and dry root rot), insect pests (including pod borer) and abiotic stress factors (including cold and drought). Cultivars have been released with resistance to ascochyta blight, fusarium wilt and cold, but limited success has been attained in the development of cultivars tolerant to insect pests. Conventional breeding techniques for self-pollinated crops are used in chickpea breeding. Mutation breeding has been carried out to create new variability, e.g. for ascochyta blight resistance. Wild Cicer species have been used in interspecific hybridization programmes, but few perennials have been tried for use in chickpea improvement. Chickpea crossing techniques are tedious. Within the CGIAR system ICARDA and ICRISAT are involved in chickpea breeding. The only substantial national chickpea programmes in the sub- Saharan region are those of Ethiopia and Sudan, which have made much progress in developing high-yielding and disease-resistant cultivars for commercial production. In Ethiopia 10 cultivars (5 each from Kabuli and Desi types) were released and more than 7 cultivars were promoted by extension for multiplication. Kenya so far released one cultivar from germplasm received from ICRISAT. Linkage maps of chickpea have been developed, and molecular markers associated with quantitative trait loci for resistance to ascochyta blight, fusarium wilt and various morphological traits have been located on these maps. Transgenic chickpea plants, e.g. showing inhibitory effects on development of Callosobruchus spp. due to an a-amylase inhibitory gene from common bean, or inhibitory effects on the growth on larvae of Helicoverpa armigera due to gene transfer from Bacillus thuringiensis, have been obtained using Agrobacterium-mediated gene transfer or biolistic transformation. Prospects Chickpea is a very suitable crop for the semi-arid regions of Africa, due to its moderate to high drought tolerance. Chickpea production in the North African countries is declining due to its low yield compared to cereals. Therefore, countries elsewhere in Africa, such as Ethiopia, Sudan and Tanzania, may increase their production to take advantage of the markets in North Africa and the Indian subcontinent. Chickpea is one of the main pulses providing affordable protein for the Ethiopian, Eritrean, and Sudanese populations, whereas more promotion is required in Kenya, Tanzania and Malawi. In Zimbabwe, Uganda, South Africa and Lesotho chickpea trials, received from ICARDA and ICRISAT, have recently been started. The development of new food products and recipes will help to increase chickpea consumption in sub-saharan Africa. Major references Bejiga, Eshete & Anbessa, 1996; Haware, 1998; Pope, Polhill & Martins (Editors), 2003; Saxena & Singh (Editors), 1987; Saxena et al. (Editors), 1996; Singh & Saxena, 1999; Singh et al., 1997b; Smithson, Thompson & Summerfield, 1985; Telaye et al. (Editors), 1994; van der Maesen, 1989b. Other references Ahmad, 1999; Anbessa & Bejiga, 2002; Bejiga, 1990; Bejiga & Degago, 2000; Bejiga et al., 1998; Choumane et al, 2000; Flandez-Galvez et al., 2003; Gillett et al., 1971; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Joshi et al., 2001; McPhee & Muehlbauer, 2002; Polhill, 1990; Popelka, Terryn & Higgins, 2004; Singh, 1993; Thulin, 1989a; Upadhyaya, Bramel & Singh, 2002; USDA, 2004; van der Maesen, 1972; Westphal, 1974; Williams et al., Sources of illustration van der Maesen, 1989b. Authors G. Bejiga & L.J.G. van der Maesen CODCLACRYMA-JOBI L. Protologue Sp. pi. 2: 972 (1753). Family Poaceae (Gramineae) Chromosome number 2n = 20 Vernacular names Job's tears, adlay (En). Larmes de Job, larmilles, herbe à chapelets (Fr). Lâgrimas de Job, lâgrimas de Nossa Senhora, erva dos rosârios (Po). Mtasubihu, mtasbihi (Sw). Origin and geographic distribution Job's tears is indigenous to southern and eastern Asia. It has been cultivated since ancient times, years ago in India, 2000 years ago in China, and was very important

45 COIX 47 before maize and rice became widespread staple foods. At present Job's tears is cultivated as a minor cereal crop throughout the tropics and subtropics, especially in Asia. Plants escaped from cultivation occur as weeds. In Africa Job's tears is naturalized in most countries but only very occasionally cultivated (e.g. in Liberia). Uses Types of Job's tears with soft-shelled false fruits can be easily husked and have large grains which are eaten in the same way as rice, alone or mixed with it. They can be substituted for rice in all foodstuffs. The grain can also be roasted before husking and then used in porridge, cakes, soups and other foods or in the preparation of sweets. Dough made from the flour will not rise because of the absence of gluten. A good mixture for bakery purposes is 70% wheat flour and 30% Job's tears flour. The raw grain tastes sweet and is often eaten as a snack. In Africa Job's tears is considered a famine food. Both alcoholic and non-alcoholic drinks are prepared from it. A beer made from the pounded grain is popular among Indian hill tribes and in the Philippines. The whole grain and the bran are fed to poultry and the flour can replace maize flour in poultry feed. Job's tears is often given as a fodder, especially for cattle and horses. It is suitable for silage, and straw and leaves are used for thatching. The grain and flour of Job's tears are easily digestible and given to people in weak condition. They are believed to have medicinal value with diuretic, depurative, anti-inflammatory and antitumour activity. A decoction of the leaves is drunk against headache, rheumatism and diabetes. Sap of the stem is applied against insect bites. A decoction of the roots is used as a vermifuge and to treat dysentery, gonorrhoea and menstrual disorders. Almost everywhere where Job's tears grows, the decorative, hard-shelled false fruits of the wild types are used as beads for necklaces, rosaries, rattles, curtains etc., and in Africa they are often worn at ritual and religious occasions. The whole inflorescence is sometimes used in dried flower arrangements. Properties Whole grain of Job's tears contains per 100 g edible portion: water 8.9 g, energy 1394 kj (333 kcal) protein 10.4 g, fat 5.3 g, carbohydrate 66.5 g and fibre 10.5 g. The hulled grain contains per 100 g edible portion: water 11.6 g, energy 1511 kj (361 kcal), protein 14.8 g, fat 4.9 g, carbohydrate 66.9 g, fibre 0.5 g, Ca 47 mg, P 254 mg, Fe 6.0 mg, ß-carotene 0 mg, thiamin 0.26 mg, riboflavin 0.19 mg and niacin 4.7 mg (Leung, Busson & Jardin, 1968). The content of essential amino acids per 100 g protein (16 g N) is: tryptophan 0.5 g, lysine 1.9 g, methionine 2.6 g, phenylalanine 4.9 g, threonine 3.0 g, valine 5.7 g, leucine 13.6 g and isoleucine 3.9 g (Busson, 1965). The root contains coixol, which is analgesic and sedative. Methanolic extracts of the grains showed an antiproliferative effect on human lung cancer cells in vitro and in vivo and might reduce the risk of tobacco-induced lung tumorigenesis. The grains might also be beneficial for the treatment of allergic disorders. Botany Erect, perennial, strongly tillering grass up to 3 m tall, often cultivated as an annual; stem (culm) filled with pith, glabrous, branched in the upper part. Leaves alternate, simple and entire; leaf sheath short, glabrous or with long hairs at apex; ligule short and membranous; blade linear to ovate-lanceolate, cm x cm, base rounded to almost cordate, apex acute, margins rough, upper surface smooth or scabrid, midrib prominent. Inflorescences in axils of upper leaves, solitary or Coix lacryma-jobi - 1, flowering stem; 2, male inflorescence; 3, male spikelet; 4, female inflorescence with cupule partly removed. Source: PROSEA

46 48 CEREALS AND PULSES 2-7-fascicled and arranged panicle-like, on peduncle 3-6 cm long, consisting of 2 unisexual racemes; female raceme enclosed by a hollow, bony, globular to ovoid-ellipsoid cupule 5 15 mm long, shiny, white, pale brown, grey, bluish or black, with a sessile spikelet accompanied by 2 barren pedicels; male raceme 3-5 cm long, exserted from the mouth of the cupule, with about 10 spikelets borne in pairs or threes, one pedicelled, the other(s) sessile. Female spikelet 2-flowered, with orbicular glumes, lower floret reduced to an orbicular lemma, upper floret with membranous lemma and palea and superior ovary with 2 stigmas exserted from the mouth of the cupule; male spikelet lanceolate to ellipsoid, 7-8 mm long, 1-2-flowered, lower glume winged, upper glume boat-shaped, each floret with membranous lemma and palea and 3 stamens. Fruit a caryopsis (grain) enclosed by the cupule (shell of false fruit), globose, dark red in hard-shelled types, pale brown in softshelled types. Coix comprises about 5 closely related species, all native in Asia, but some have been introduced elsewhere. Mainly based on characteristics of the false fruit, 4 varieties have been distinguished in Coix lacryma-jobi, but only var. lacryma-jobi occurs in Africa; it is characterized by ovoid, hard, smooth false fruits. Most agricultural information (from outside Africa) concerns var. ma-yuen (Rom.Caill.) Stapf, with ovoid to pear-shaped, quite soft, striate false fruits; it is cultivated as a cereal. Job's tears takes about 1-2 weeks to germinate, depending on the moisture content of the soil. Both self-pollination and cross-pollination are possible, with the latter usually being predominant. Total crop duration is 4 6( 8) months. When most of the seeds are ripe, the plant starts to dry. Job's tears follow the C4- cycle photosynthetic pathway. Ecology Job's tears occurs wild in swampy locations and along watercourses. It is a quantitative short-day plant and requires high temperatures, abundant rainfall and reasonably fertile soils. In the tropics it occurs from sealevel up to 2000 m altitude, in Africa often around villages and on abandoned fields. Management Job's tears is usually propagated by seed. The 1000-seed weight is g. Seed is dibbled, 5 cm deep, at the start of the rains, after ploughing or hoeing the field. Row spacing is cm, and seed rate 7-15 kg/ha. When cultivated as an intercrop, it is sown at random or plants are grown along field borders. Propagation by cuttings is possible and recommended for fodder production. Propagation by seed gives deeper rooting, and, consequently, better drought tolerance and higher grain yield. Weeding is necessary up to 60 days after sowing or until Job's tears has reached a plant height of 40 cm. In general, plants are not given much care, but when young they need abundant water. They respond well to application of manure; chemical fertilizers or insecticides are not used. The most serious disease of Job's tears is smut (Ustilago coicis) which destroys the ovaries. Smut can severely damage crops and therefore seed treatment with fungicide or with hot water (60-70 C) for at least 10 minutes before sowing is recommended. Another important disease of Job's tears is leaf blight (Bipolaris coicis); control measures include burning of crop residues, spraying of fungicides and the use of more resistant cultivars. Tar leaf spot (Phyllachora coicis), rust (Puccinia operata) and Ustilago lachrymae-jobi (synonym: Sporisorium lachrymae-job) are some of the other diseases attacking Job's tears. Rats, birds and sometimes grasshoppers and termites may cause considerable losses. Job's tears is normally harvested 4-6 months after sowing, depending on the cultivar and the season. Usually, whole plants are cut at the base when the grain is ripe. The stubble can be left in the field and will then tiller again; the new fresh leaves are an excellent fodder. Normal yield of husked grain varies from 2-4 t/ha. The hulling percentage is 30-50%. If cultivated for fodder, several cuts per year are possible. After threshing and husking, which is done manually or with the same tools as for rice, the grain is sun-dried on mats. Under humid conditions, the storability of the grain is limited, but is better for whole than for husked grain. Genetic resources and breeding The largest germplasm collections of Job's tears are held in China (Institute of Crop Germplasm Resources (CAAS), Beijing, 87 accessions) and the Philippines (Institute of Plant Breeding, University of the Philippines Los Banos (UPLB), College, Laguna, 31 accessions). The greatest variation in wild forms occurs in India and Myanmar, in cultivated Job's tears in South-East Asia. In the course of time, Job's tears has been selected by farmers for easy husking, resulting in var. ma-yuen. However, the crop has a relatively long growing season, shows uneven ripening and variable yields. Nevertheless, the large variability in Job's

47 CORDEAUXIA 49 tears offers opportunities for breeding programmes, e.g. to obtain resistance against smut disease. In Japan selection work focuses on the use as a fodder. In Brazil a high-yielding 'dwarf cultivar, probably introduced from Japan, has been selected and distributed. Prospects Although enjoyed locally by many people, Job's tears is still decreasing in popularity in favour of higher-yielding cereals, mainly maize and rice. However, because it is less susceptible to diseases and pests, it can be grown where other crops are difficult to cultivate, it does not need much care, it is highly nutritious and has promising medicinal properties, Job's tears deserves more research attention. Major references Burkill, 1994; Chang, Huang & Hung, 2003; Clayton & Renvoize, 1982; Mello et al, 1995; van den Bergh & Iamsupasit, Other references Busson, 1965; Chang & Hwang, 2002; Gurib-Fakim, Guého & Bissoondoyal, 1997; Hsu et al., 2003; Leung, Busson & Jardin, 1968; Naku Mbumba, Walangululu & Basiloko, 1984; Neuwinger, 2000; Numata et al., 1989; Purseglove, 1972; Watt & Breyer-Brandwijk, Sources of illustration van den Bergh & Iamsupasit, Authors P.C.M. Jansen Based on PROSEA 10: Cereals. CORDEAUXIA EDULIS Hemsl. Protologue Bull. Misc. Inform. Kew: 361 (1907). Family Caesalpiniaceae (Leguminosae - Caesalpinioideae) Chromosome number 2M = 24 Vernacular names Yeheb nut, yeheb bush (En). Yeheb (Fr). Origin and geographic distribution Cordeauxia edulis is endemic to south-eastern Ethiopia (eastern Ogaden) and central Somalia. It is cultivated on a small scale in Somalia and near Voi in Kenya, where it was introduced in the 1950s. It has been introduced on an experimental scale into Sudan, Tanzania, Yemen, Israel and the United States. Uses In its native region the seeds ('yeheb nuts') of Cordeauxia edulis are an important food for pastoralists, especially as a famine food during drought periods. They are eaten fresh, dried, roasted or boiled. The seeds taste sour when eaten fresh or dried, but have a Cordeauxia edulis - wild sweetish, agreeable, chestnut-like taste after roasting. The water in which the seeds have been boiled is sweet and is sometimes consumed. The seed oil is useful for soap making. The seeds have been mentioned as a coffee substitute. Cordeauxia edulis is said to regulate gastric secretion and to permit treatment of ulcers due to hot food. It is also believed to alleviate anaemia by augmenting the number of red blood cells. The leaves are made into a tea. Cordeauxia edulis is an important dryseason fodder for camels, goats, sheep and cattle, but in the rainy season other plants are preferred. The red pigment in the glands on several plant parts forms vividly coloured, fast and insoluble combinations with many metal mordants, and is locally used for dyeing textiles. The wood is used as firewood. Production and international trade The seeds of Cordeauxia edulis are mostly consumed locally, but are also sold in towns. Demand exceeds supply because of rapidly diminishing plant populations. From Ethiopia the seeds are exported to Somalia and Arab countries, but no quantitative information is available. Cordeauxia edulis seeds have export potential for European markets as 'dessert nuts'. Properties Shelled Cordeauxia edulis seeds contain per 100 g edible portion: water 11.1 g, energy 1666 kj (398 kcal), protein 10.8 g, fat 12.0 g, carbohydrate 63.9 g, fibre 1.4 g, Ca 32 mg, P 185 mg and Fe 6.4 mg (Leung, Busson & Jardin, 1968). The protein content is considerably less than that of most pulses, but the fat content is higher. In various studies the protein was found to resemble that of other pulses in containing considerable and well-balanced

48 50 CEREALSAND PULSES amounts of essential amino acids, especially lysine ( %), and being deficient in methionine. The seed lipids contain palmitic acid (26-31%), stearic acid (12-13%), oleic acid (31-32%), linoleic acid (25-30%) and linolenic acid (traces). The seed oil is yellow. The seeds contain trypsin inhibitors, which can be inactivated by boiling. Cordeauxia edulis leaves from Somalia have a low crude protein content ( %), energy content ( kj per 100 g dry matter) and in vitro dry matter digestibility ( %). Furthermore they have a high tannin content ( %), which reduces their feed quality. The leaves contain N %, P 0.1%, Ca %, Mg % and S %. According to herdsmen the meat of animals fed with Cordeauxia edulis is particularly tasty. Cordeauxia edulis is reputed to cause intestinal disorders in goats when eaten as the sole diet. The red pigment of Cordeauxia edulis is cordeauxione (cordeauxiaquinone), a naphthaquinone which is unknown in other plants. The leaves contain % of this dye. When fresh leaves are handled, they stain the hands red. When animals eat the leaves, their teeth are stained orange-red and the dye is also deposited as a calcium complex in their bones, which become pink. This colouration is considered a sign of good meat quality, e.g. in Somalia and Saudi Arabia. The wood of Cordeauxia edulis has been described as good firewood, inflammable even when wet. Description Densely branched, evergreen shrub or small tree up to 2.5(-4) m tall, with a long taproot up to 3 m deep and lateral roots at cm below the soil surface extending up to 2.5 m; stem with conspicuous red glands. Leaves alternate, paripinnate, without stipules; leaflets (2-)4-8(-12), elliptical-oblong, up to 3(-5) cm x 1.5(-2.5) cm, leathery, olive-green above, paler with many red glands beneath. Inflorescence a terminal few-flowered raceme. Flowers bisexual, almost regular, 5-merous, c. 2.5 cm in diameter; sepals oblong, c. 1 cm long, obtuse, green with red glands; petals almost equal, c. 1.5 cm long, yellow, clawed; stamens 10, free, straight, filaments hairy below the middle; ovary superior, 1-celled, shortly stalked, densely glandular; stigma obtuse. Fruit an ovoid pod, 4-6 cm x 2 cm, shortly stalked, with a curved beak, opening by 2 hard valves, l(-6)- seeded. Seed ovoid, cm long, with thin, easily cracked testa. Seedling with epigeal germination; cotyledons thick. Other botanical information Cordeauxia Cordeauxia edulis - 1, flowering twig; 2, fruit; 3, seed; 4, seed kernel. Redrawn and adapted by Achmad Satiri Nurhaman comprises a single species. It is closely related to Caesalpinia and Stuhlmannia. Cordeauxia edulis is rather variable, and sometimes two types are distinguished: 'suley' ('sulei') and 'moqley'('mogollo'). 'Suley' is pale green, with a large stem diameter and large leaflets. 'Moqley' is dark green, with small stem diameter and small leaflets. Pods of the 'moqley' type contain a large single seed. Pods of the 'suley' type contain several seeds, which are compressed laterally and smaller in size. The seeds of the 'moqley' type are claimed to be sweeter. Mixed stands of the two types exist but are rare. The leaves of Cordeauxia edulis have an extremely thick cuticle and mesophyll consisting of palisade cells with lateral walls capable of folding in a concertina-like way. This may enable the leaves to survive extended periods of drought and store water quickly when available, thus allowing them to remain evergreen. Growth and development Germination of Cordeauxia edulis is rapid. Subsequent growth of the aerial parts is very slow, especially in the seedling stage, whereas the root system grows rapidly. Plants 60 cm tall may already

49 CORDEAUXIA 51 have roots 2 m long. Under natural conditions flowering starts just before the onset of the rains, when the relative humidity rises, or immediately after the first rains, whereas some sources indicate flowering is year-round but more profuse during the rainy season. The floral parts fall soon after pollination, leaving only the fertilized ovary. The fruit ripens days after flowering. Unlike in many other plants, seeds of Cordeauxia edulis mature when the plant moisture content is at its peak. Fruit development stops when the rain ceases and the ovaries remain dormant for 4-5 months, resuming ripening after the rains have returned. Cordeauxia edulis requires 3 4 years to bear fruit. The plants are long-lived, some reaching more than 200 years according to Somali sources, and they coppice well. It is unclear whether Cordeauxia edulis is able to fix atmospheric nitrogen. Ecology In Ethiopia and Somalia Cordeauxia edulis is found in semi-desert regions in Acacia-Commiphora deciduous bushland and shrub vegetation at (100-) (-1000) m altitude, with a minimum distance of 100 km to the Indian Ocean. These regions have an average annual temperature of C, an average annual rainfall of (-400) mm and two rainy seasons. Cordeauxia edulis is resistant to normal drought periods of 4-5 months and occasional drought of up to 15 months. It does not tolerate frost. It grows on deep, permeable, reddish, sandy, slightly alkaline (ph up to 8-8.5), noncalcareous soils with a very low nutrient status. Cordeauxia edulis does not tolerate waterlogging. Propagation and planting Cordeauxia edulis is normally propagated by seed, but vegetative propagation through stem cuttings is also possible. The 100-seed weight is g. The seed is often said to be viable for a few months only, but seed coated in wood ash and stored in a sack is reputed to remain viable for at least a year. Direct sowing in the field seems preferable, as the fast-growing taproot is easily damaged in transplanting, with mortality rates of up to 100%. No information is available on optimum plant densities and spacings. Under natural conditions in Somalia there are up to 320 plants/ha, depending on growing conditions and distance from villages and water points. Management Cordeauxia edulis is usually collected from the wild. Ample water is needed for seedling establishment, but once the plants are established, little care is needed. Diseases and pests Cordeauxia edulis shrubs are essentially free of insect pests, but storage pests, such as weevils and larvae of moths, heavily attack the seeds. Harvesting Cordeauxia edulis fruits are picked from the plant, the fruit wall is peeled off and the seeds are placed in sacks. The seeds are often harvested before maturity, which may be a factor in the low seed viability often encountered. Usually all seeds are removed from the plant at the same time, hampering regeneration of natural stands. Fruits can be harvested twice a year, provided rainfall is adequate during both rainy seasons. Yield The seed yield of Cordeauxia edulis is 5 8 kg per plant per year, but may be zero in drought years. The estimated average forage production is kg/ha (1.4-2 kg/plant). Handling after harvest To prevent Cordeauxia edulis seeds from being attacked by insects, freshly picked seeds are roasted or boiled to kill insects and harden the seed coat. In this form they fetch a higher price on the market, but the practice contributes to the difficulty of obtaining viable seed for planting. Pastoralists keep the seeds for many years in containers made of tanned, dried camel leather. For dyeing, Somalis pulverize about 200 g of dried leaves in water to dye about 10 m 2 cotton cloth. Alkaline extracts develop a more intense violet colour than neutral or slightly acid extracts. Genetic resources The populations of Cordeauxia edulis declined in the 20 th century due to deterioration of the vegetation caused by overgrazing, and overharvesting of the seed. In the IUCN Red List of Threatened Plants (1997) Cordeauxia edulis is classified in the category 'rare', which includes taxa with small world populations that are not at present considered endangered or vulnerable, but are at risk. Regeneration and protection of natural stands and cultivation in afforestation projects, in and outside its native region, are recommended. Germplasm collections are seriously lacking, with one accession kept in Ethiopia at the International Livestock Research Institute (ILRI), Addis Ababa, one in Kenya at the National Genebank of Kenya, Kikuyu and one in the United States at the Southern Regional Plant Introduction Station, Griffin, Georgia. Prospects Cordeauxia edulis is a useful multipurpose plant in dry areas of Ethiopia and Somalia. Natural stands are threatened by over-exploitation, and protection of natural stands as well as expansion of its cultivation

50 52 CEREALS AND PULSES are called for. Cordeauxia edulis could be a promising potential source of food and dryseason fodder for other hot, arid regions. However, the limited availability of viable seed and the shortage of knowledge on the crop, especially its propagation, agronomic practices and potential for selection and breeding, are important constraints. Major references Assefa, Bollini & Kleiner, 1997; Bally, 1966; Booth & Wickens, 1988; Drechsel & Zech, 1988; Miège & Miège, 1978; National Academy of Sciences, 1979; Seegeler, 1983; Thulin, 1989a; Thulin, 1993; Yahya & Durand, Other references Bekele-Tesemma, Birnie & Tengnäs, 1993; Brenan, 1967; Curtis, Lersten & Lewis, 1996; Drechsel, 1988; Drechsel & Assefa, 1991; El-Zeany & Gutale, 1982; Eugster, 1967; Greenway, 1947; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hedberg, 1979; International Centre for Research in Agroforestry (ICRAF), undated; Kebebew, 1988; Lepidi, Nuti & Capretti, 1979; Leung, Busson & Jardin, 1968; Lewis, 1996; Miège, Crapon de Caprona & Lacotte, 1978; Walter & Gillett (Editors), 1998; Wickens, 1998; Zemede Asfaw & Mesfin Tadesse, 2001; Zimsky, Sources of illustration Booth & Wickens, 1988; Thulin, Authors M. Brink CRAIBIA BROWNII Dunn Protologue Journ. Bot. 49: 108 (1911). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Synonyms Craibia elliottii Dunn (1911). Origin and geographic distribution Craibia brownii is found in north-eastern DR Congo, Kenya, Uganda, Tanzania, Zambia and possibly in Rwanda. Uses The seeds of Craibia brownii are edible after long cooking. The wood is used for building poles, tool handles and wooden spoons, and as firewood and to make charcoal. Craibia brownii is also planted as a shade tree. Properties The wood of Craibia brownii is whitish and hard, and has a fine texture. Botany Small to medium-sized tree up to 24 m tall, with a pale grey bark. Leaves alternate, imparipinnate with 3 8 leaflets; stipules oblong, often semi-persistent; petiole cm long, rachis up to 12 cm long; stipels sometimes present; petiolules l-2(-5) mm long, wrinkled; leaflets alternate, elliptical, lanceolate or oblong, 4-15 cm x cm, base cuneate to rounded, apex gradually acuminate, glabrous, shiny. Inflorescence a many-flowered terminal or axillary raceme 4-15 cm long, densely brown-pubescent; bracts oblong, up to 5 mm long, caducous. Flowers bisexual, papilionaceous; pedicel up to 12(-19) mm long; calyx brown-pubescent, tube 4-5 mm long, lobes very broad, c. 2 mm long; corolla bluish, pinkish or white, mm long, standard with a short claw, wings and keel with well-marked auricles; stamens 10, 9 fused and 1 free, sheath mm long, free parts 5 6 mm long; ovary superior, shortly stalked, mm long, densely hairy, style cylindrical, 5-6 mm long. Fruit a shortly stalked, flat pod, cm x cm, asymmetric, shortly beaked, glabrescent, dehiscing with twisted valves, 2-3- seeded. Seeds ellipsoid, c. 17 mm x 15 mm, black. Seedling with hypogeal germination. Craibia comprises 10 species and is confined to tropical Africa. Ecology Craibia brownii is found in dry and moist forest and along rivers, at m altitude, in areas with an annual rainfall of mm. Genetic resources and breeding Craibia brownii is not threatened by genetic erosion as it is widespread and locally common. Prospects Since very little is known about Craibia brownii, its prospects are unclear. Research is needed on the nutritional and chemical properties of the seeds. Major references Beentje, 1994; Gillett et al., 1971; Hauman et al., 1954b; Lovett, Ruffo & Gereau, 2003; Troupin, Other references ILDIS, 2002; USDA, ARS & National Genetic Resources Program, Authors M. Brink CROTALARIA KARAGWENSIS Taub. Protologue Engl., Pflanzenw. Ost-Afrikas C: 204 (1895). Family Papilionaceae (Leguminosae- Papilionoideae, Fabaceae) Synonyms Crotalaria lugardiorum Bullock (1932). Origin and geographic distribution Crotalaria karagwensis is distributed in Central and East Africa, from Cameroon to Ethiopia and southward to DR Congo and Tanzania. Uses The seeds of Crotalaria karagwensis are considered edible in Kenya.

51 CROTALAEIA 53 Properties Various toxic compounds (alkaloids and non-protein amino acids) are present in Crotalaria spp., but toxin levels in Crotalaria karagwensis are not known. Botany Erect, annual herb up to 1 m tall, often with spreading, weakly ascending branches from the base; stem appressed hairy. Leaves alternate, simple; stipules linearsubulate, up to 3.5 mm long; petiole 1-2 mm long; blade linear-lanceolate to elliptical, cm x 2-12 mm, acute to rounded at apex, appressed hairy beneath. Inflorescence a terminal or axillary lax raceme 9-24 cm long, (6-) flowered. Flowers bisexual, papilionaceous; pedicel c. 5 mm long; calyx (4.5-)6-8 mm long, upper lobes narrowly attenuate-triangular, longer than the tube; corolla yellow, standard elliptical, c. 9 mm x 7 mm, with reddish-purple veins, wings c. 7 mm x 2 3 mm, keel angular, 7-11 mm x 4 mm, with a long straight twisted beak; stamens 10, all joined; ovary superior, oblong, c. 3.5 mm long, 1-celled, style c. 7 mm long. Fruit an oblong, clubshaped pod, narrowed basally into a 2 3 mm long stipe, c. 2.5 cm x 3.5 cm x 0.5 cm, seeded. Seeds obliquely heart-shaped, mm in diameter, smooth. Crotalaria comprises about 600 species distributed throughout the tropics and subtropics, with about 500 species in tropical Africa. Crotalaria karagwensis belongs to section Crotalaria, subsection Longirostres. In this subsection levels of toxic compounds are in general relatively low, although most species contain the free amino acid y-glutamyltyrosine. Ecology Crotalaria karagwensis occurs at m altitude in grassland and woodland; it also persists on roadsides and in cultivated land. Genetic resources and breeding No germplasm collections of Crotalaria karagwensis are known to exist. In view of its wide distribution Crotalaria karagwensis is not threatened by genetic erosion. Prospects It is unclear to what extent Crotalaria karagwensis seeds are eaten in tropical Africa. More information is needed on the levels of toxic compounds in the seeds and appropriate processing methods to eliminate these compounds. Major references Burkill, 1995; Gillett et al, 1971; Pilbeam & Bell, 1979; Polhill, 1982; Thulin, 1989a. Other references Hepper, 1958; ILDIS, 2005; Toussaint et al., Authors M. Brink CROTALARIA LACHNOPHORA Höchst, ex A.Rich Protologue Tent. fl. abyss. 1: 151 (1847). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number n = 8 Vernacular names Crotalaire à toison (Fr). Origin and geographic distribution Crotalaria lachnophora is widespread in tropical Africa, from Senegal east to Ethiopia and south to Angola and Zimbabwe. It has recently been introduced into Madagascar from Rwanda. Uses The seeds of Crotalaria lachnophora are considered edible in DR Congo. Crotalaria lachnophora is promoted in Rwanda as a green manure crop in rotation systems, together with pigeon pea (Cajanus cajan (L.) Millsp.) and Tephrosia vogelii Hook.f. In Madagascar it is being used experimentally as a cover crop for fallow land and in contour hedges. In Guatemala it has been recommended as a shade plant for coffee plantations and for soil conservation. Leaf sap is dropped into the ear or drunk to treat otitis. Properties Various alkaloids and nonprotein amino acids (y-glutamyltyrosine, isowillardiine, 2-piperudinecarboxylic acid) have been detected in Crotalaria lachnophora seeds and may cause toxicity. However, amino acids known to be toxic to mammals and birds and present in many Crotalaria species were not detected in Crotalaria lachnophora. Botany Perennial herb or shrub up to 3 m tall, much-branched above; branches densely hairy. Leaves alternate, 3-foliolate; stipules oblong-falcate, cm x 2-8 mm, caudate; petiole (-5) cm long; petiolules mm long; leaflets oblanceolate to obovate, 3-7.5( 10) cm x cm, base cuneate, apex acute to rounded, densely appressed pubescent beneath. Inflorescence a terminal, lax raceme cm long, few-many-flowered. Flowers bisexual, papilionaceous; pedicel 5-11 mm long; calyx 11-15(-18) mm long, spreading hairy, lobes twice as long as the tube; corolla yellow, fading to orange-red, standard circular, c. 20 mm x mm, wings broadly oblong, mm x mm, keel abruptly rounded in lower half, (13-)20-24(-26) mm x 11 mm, with a rather short, blunt, slightly incurved beak; stamens 10, all joined; ovary superior, 1- celled, style mm long. Fruit a broadly cylindrical pod, cm x 1 2 cm, hairy, seeded. Seeds oblong to kidney-shaped, mm long, granulate, orange-yellow.

52 54 CEREALS AND PULSES Crotalaria comprises about 600 species distributed throughout the tropics and subtropics, with about 500 species in tropical Africa. Crotalaria lachnophora belongs to section Chrysocalycinae, subsection Stipulosae. Ecology Crotalaria lachnophora occurs in grassland and woodland, sometimes in thorn scrub; it is also found on roadsides and in disturbed or cultivated locations, at m altitude. In Nigeria it occurs in regions with an average annual rainfall of mm, on acidic, ferruginous soils. Genetic resources and breeding One accession of Crotalaria lachnophora from Kenya is kept in the National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu. Crotalaria lachnophora is widely distributed and not threatened by genetic erosion. Prospects Although the seeds of Crotalaria lachnophora are considered edible, possibly toxic compounds have been detected in the seeds. More information is needed on the toxicity of the seeds and appropriate processing methods to eliminate the toxic compounds. Crotalaria lachnophora has some potential as a green manure. Major references Beentje, 1994; Burkill, 1995; Gillett et al, 1971; Pilbeam & Bell, 1979; Polhill, Other references Berhaut, 1976; du Puy et al., 2002; Hepper, 1958; Husaini & Gill, 1985; ILDIS, 2005; Moller, 1990; Neuwinger, 2000; Thulin, 1989a; Toussaint et al., 1953; Wiedenroth, Authors M. Brink DlGITARIAEXILIS (Kippist) Stapf Protologue Bull. Misc. Inform. Kew 1915: 385 (1915). Family Poaceae (Gramineae) Chromosome number In = 54 Vernacular names Fonio, hungry rice, white fonio (En). Fonio, fonio blanc, petit mil (Fr). Origin and geographic distribution Fonio is only known from cultivation and its exact origin is unknown, but it is of ancient cultivation in West Africa. It may have derived from Digitaria longiflora (Retz.) Pers. in the inland delta region of the Niger. Historical records of the use of fonio as a cereal go back to the 14 th century. Nowadays fonio is grown scattered from Cape Verde and Senegal to Lake Chad, especially on the Fouta Djallon Plateau in Guinea, the Bauchi Plateau in Nigeria and in Digitaria exilis -planted north-western Benin. It is also grown in the Dominican Republic. Uses Fonio is a staple food in various parts of West Africa, where it is also known as 'acha' or 'fundi', but it is also a prestige food ('chiefs food') and a gourmet item. In the Hausa regions of Nigeria, Benin, Togo and Ghana, special couscous types ('wusu-wusu') are prepared with fonio. In southern Togo, the Akposso and Akebou people prepare fonio with beans in a dish for special occasions. In Nigeria fonio flour is made into thick, unfermented porridges ('tuwo acha'), and fermented grains are used for thin porridges ('kunu acha'). Boiled whole grains are eaten with vegetables, fish or meat. In northern Togo, the Lamba people brew beer ('tchapalo') from fonio. It is also popped and can be mixed with other flours to make bread. In the Dominican Republic fonio flour is made into porridges and creams, mixed with other cereal flours to make cookies, and it is used in the preparation of candy and fermented beverages; aside from everyday meals, fonio is also associated with various religious festivities inherited from African ancestors. Fonio grain is a valuable, easily digested feed for farm animals. The straw and chaff are excellent fodder and are often sold in markets for this purpose. Chopped fonio straw is mixed with clay to build walls of houses. The straw is also used as fuel for cooking or to produce ash for potash. Fonio grain is considered to have medicinal properties; it is recommended for lactating women and diabetic people. Production and international trade According to FAO statistics the average world production of fonio (the major share) and black fonio

53 DlGITAEIA 55 (Digitaria iburua Stapf) together in amounted to 257,000 t per year from 360,000 ha, all in West Africa. The main producing countries are Guinea (128,000 t per year in , from 137,000 ha), Nigeria (78,000 t from 142,000 ha), Mali (21,000 t from 33,000 ha), Burkina Faso (13,000 t from 16,000 ha) and Côte d'ivoire (11,000 t from 22,000 ha). The production in the Dominican Republic is not known. FAO statistics show an increase in world production from around 180,000 t per year in the early 1960s to around 260,000 t in the early 2000s, with an increase in acreage from around 280,000 ha to about 360,000 ha. Fonio is hardly traded outside West Africa, except for small quantities sold as luxury product in Europe. Properties The composition of whole fonio grain per 100 g edible portion is: water 11.2 g, energy 1390 kj (332 kcal), protein 7.1 g, fat 3.0 g, carbohydrate 74.4 g, fibre 7.4 g, Ca 41 mg, P 191 mg, Fe 8.5 mg, thiamin 0.24 mg, riboflavin 0.10 mg and niacin 1.9 mg (Leung, Busson & Jardin, 1968). The essential amino-acid content per 100 g grain is: tryptophan 111 mg, lysine 205 mg, methionine 441 mg, phenylalanine 402 mg, threonine 315 mg, valine 457 mg, leucine 772 mg and isoleucine 315 mg (FAO, 1970). The amino acid composition of fonio is comparable with that of other cereals, but it has a relatively high methionine content. The palatability of fonio grain is considered high. Adulterations and substitutes Black fonio and Guinea millet (Brachiaria deflexa (Schumach.) Robyns) are used as substitutes of fonio. Description Ascending, free-tillering annual grass up to 80 cm tall, with delicate kneed stems. Leaves alternate, simple; leaf sheath glabrous, smooth, striate; ligule membranous, broad, c. 2 mm long; blade linear to lanceolate, gradually tapering to an acute apex, 5-15 cm x cm, glabrous. Inflorescence a terminal digitate panicle of 2-5 slender, spike-like primary branches up to 15 cm long. Spikelet up to 1 mm stalked, narrowly ellipsoid, mm long, acute, glabrous, pale green, 2-flowered; lower glume hyaline, minute, upper glume broadly oblong, slightly shorter than spikelet, hyaline between the 3-5 green veins; lower floret sterile, upper floret bisexual; lemma about as long as spikelet, 7-9-veined; palea slightly shorter than lemma; stamens 3; ovary superior, with 2 stigmas. Fruit a caryopsis (grain), oblong to globose-ellipsoid, c. 0.5 mm long, white to pale brown or purplish. Other botanical information Digitaria is Digitaria exilis - 1, plant habit; 2, spikelet; 3, grain- Redrawn and adapted by Achmad Satiri Nurhaman a taxonomically difficult genus comprising about 230 species in tropical, subtropical and warm-temperate regions, particularly in the Old World. Digitaria barbinodis Henr., occurring in Mali and Nigeria, is harvested as a wild cereal during times of scarcity and is occasionally grown in Nigeria. Digitaria ciliaris (Retz.) Koeler is sometimes eaten as a supplementary food (Chad) or as a famine food. Digitaria debilis (Desf.) Willd., Digitaria fuscescens (Presl) Henrard, Digitaria leptorhachis (Pilg.) Stapf, Digitaria longiflora (Retz.) Pers., Digitaria nuda Schumach. and Digitaria ternata (A.Rich) Stapf are also known to be eaten as famine foods in tropical Africa, but are considered more important as forage or auxiliary plant. In India (Assam) and Vietnam Digitaria cruciata (Nees ex Steud.) A.Camus ('raishan') is grown for food and fodder, whereas Digitaria sanguinalis (L.) Scop, ('crabgrass') is or was grown as a cereal in Europe, Asia and America. Diversity within Digitaria exilis is broad, with a large number of locally cultivated landraces, differing in plant habit, plant colour, glume colour, grain size and length of the crop cycle. Based on morphology, 5 varieties have been

54 56 CEREALS AND PULSES distinguished: - var. gracilis Portères: leaf margin curled, inflorescence with 2 primary branches, each with spikelets per 10 cm, spikelets in groups of (2-)3(-4) and in 1-2 rows, stalks rough; early-maturing; Kankan region (Guinea). - var. striata Portères: leaf margin slightly curled, inflorescence with 2 primary branches, each with spikelets per 10 cm, spikelets in groups of (2-)3(-4) and mostly in 1 row, stalks smooth; earlymaturing; Casamance (Senegal), Guinea, Mali and Burkina Faso. - var. rustica Portères: robust plants, inflorescence with (2 )3-4( 5) primary branches, each with spikelets per 10 cm, spikelets in groups of (3 )4 and in 2 3 rows, stalks smooth; late-maturing; Casamance (Senegal), Guinea, Mali and Burkina Faso. - var. mixta Portères: robust plants, vegetative parts reddish pigmented, inflorescence with (2 )3-4(-5) primary branches, each with spikelets per 10 cm, spikelets in groups of (3 )4 and in 2 3 rows, stalks smooth; latematuring; Guinea. - var. densa Portères: tall, strong plants, with a long vegetative cycle, inflorescence with 3 4 primary branches, each with spikelets per 10 cm, spikelets in groups of 2(-3) and in 2 3 rows; late-maturing; Togo. Growth and development Fonio normally germinates 2-4 days after sowing and grows rapidly. Flowering usually occurs 6 8 weeks after emergence. The time from sowing to maturity is normally 2 5(-6) months. Certain landraces mature so quickly that they produce grain already 6-8 weeks after planting, long before all other cereals, and provide food early in the growing season. At maturity the stems bend down due to the weight of the grains. Fonio follows the C4 photosynthetic pathway. Ecology Fonio is grown at sea level in Gambia, Guinea-Bissau and Sierra Leone, but more often it is cultivated at m altitude. The average temperature in the growing season ranges from 20 C at higher altitudes to C near sea level. Fonio is grown in areas with an average annual rainfall of mm, but its cultivation is concentrated in regions with an average annual rainfall of mm. It is not as drought resistant as pearl millet, but fast-maturing landraces are suited to areas with short and unreliable rains. In areas with very low rainfall it is grown in valleys benefiting from run-off water. Fonio can be grown on poor, shallow, sandy or rocky soils unsuitable for other cereals, but does not prosper in saline or heavy soils. On the Fouta Djallon Plateau of Guinea, it grows on acidic soils with very high aluminium contents. Propagation and planting Fonio is propagated by seed. The 1000-seed weight is mg. Fonio is usually sown at the beginning of the rainy season. Soil preparation is minimal: the fallow vegetation is burnt and the ashes spread, and the soil may be loosened by superficial cultivation. Seed, mixed with an equal quantity of sand or ashes, is usually broadcast, and covered with soil by a light hoeing or brushing with tree branches. The seed rate is kg per ha. Fonio is sometimes raised in a nursery and planted out in the field. Fonio is normally grown as a sole crop, but sometimes intercropped with sorghum or pearl millet. Farmers in Guinea commonly sow various fonio types together and later fill in any gaps with Guinea millet. Management Although it has been stated that fonio seldom needs weeding due to its quick establishment and the high seed rates applied, other sources indicate that a weeding at 4-5 weeks after sowing is necessary for good yields. Fonio is usually not fertilized and little is known of its nutrient requirements. In crop rotations fonio often follows rainfed rice, as a short-cycle crop before another crop is sown in the same season. It is also grown at the end of a rotation. Diseases and pests Fonio is susceptible to rust (Puccinia oahuensis). Resistance to the nematodes Meloidogyne incognita and Meloidogyne javanica has been recorded in soils where other plant species were infected. Birds can cause serious losses, so bird scaring is usually necessary. Fonio is attacked by parasitic plants of the genus Striga. Fonio seed is not liable to damage by storage pests and stores well. Harvesting Fonio is usually cut with a knife or sickle, tied into sheaves, dried and stored under cover. Mechanization is difficult because of lodging. When plants are dry, the grain shatters easily, and therefore it is better to harvest before the dry season has fully established and the relative air humidity has considerably declined. Harvesting is often staggered, to suit the immediate needs of the farmer. Yield Grain yields of fonio are normally kg/ha, but yields of over 1000 kg/ha have been recorded. In marginal areas yields

55 DlGITAEIA 57 may be as low as kg/ha. Handling after harvest Fonio is normally threshed at about 8 days after harvesting, traditionally by beating or trampling. The husks remain on the grains, which therefore retain moisture and must be dried further. The grains are sufficiently dry when they run easily through the fingers. The product after threshing ('fonio paddy' or 'raw fonio') is further processed in 2 stages: husking (removal of the husks from the grains) and whitening (removal of the fruitwall and the germ). Husking and whitening are done manually and require 4-5 beatings with pestle and mortar, alternated with winnowing. To obtain a product of good quality, all dirt and sand must be removed by repeated washings. The processing cycle is difficult and time-consuming and efforts are being made to develop equipment that will make processing easier. Small-scale fonio processing enterprises can be found in towns, e.g. in Mali and Burkina Faso, aiming at urban and export markets. Genetic resources Fonio seems not threatened by genetic erosion. RAPD-analysis has shown a relatively high level of genetic diversity in fonio compared to other millets, possibly due to its outbreeding nature. Most germplasm collections made before 1990 and kept in national genebanks have been lost, but duplicates exist at IRD (Institut de Recherche pour le Développement), Montpellier, France, which keeps more than 400 fonio accessions. Fonio accessions are also conserved in Senegal, Guinea, Mali, Burkina Faso, Togo, Benin and Nigeria. In Nigeria, Benin and Togo germplasm characterization work for a better understanding and utilization of the fonio gene pool has started. Breeding So far fonio has been largely neglected in breeding programmes. Breeding efforts are being undertaken in Guinea, but no results are available so far. Improvement of fonio through traditional hybridization does not seem attractive because of insufficient knowledge on its floral biology and the extraordinarily miniature nature of its floral organs. Prospects Fonio is wrongly named 'hungry rice', because it is not grown to relieve hunger but because of its quality and contribution to food security. It is a crop with a short cycle, able to produce on very poor soils. It is appreciated as a food in West Africa, and its nutritional quality is excellent. Interesting research topics include improved plant architecture to prevent lodging, photoperiod-sensitivity, cultivation techniques, grain size, the development of less laborious processing methods and improvement of farmers' seed systems. Study of the genetic diversity of fonio and multilocational screening of germplasm are also highly recommended. Major references Burkill, 1994; Froment & Renard, 2001; Haq & Dania Ogbe, 1995; Hilu et al., 1997; National Research Council, 1996; Ndoye & Nwasike, 1993; Portères, 1976; van der Hoek & Jansen, 1996a; Vodouhè, Zannou & Achigan Dako (Editors), 2003; Vodouhè & Achigan Dako (Editors), Other references Busson, 1965; Chevalier, 1950; Cissé, ; Clayton, 1972; Cruz, 2004; de Wet, 1995c; FAO, 1970; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Harlan, 1993; Jideani, 1990; Jideani, 1999; Konkobo-Yaméogo et al., 2004; Kuta et al., 2003; Kwon-Ndung, Misari & Dachi, 1998; Leung, Busson & Jardin, 1968; Lewicki, 1974; Morales-Payân et al., 2002; Purseglove, 1972; Sarr & Prot, 1985; van der Zon, Sources of illustration Henrard, 1950; Stapf, Authors S.R. Vodouhè & E.G. Achigan Dako DlGITARIAIBURUA Stapf Protologue Bull. Misc. Inform. Kew 1915: 382 (1915). Family Poaceae (Gramineae) Chromosome number In = 54 Vernacular names Black fonio, iburu, black acha (En). Fonio noir, manne noire, ibourou (Fr). Origin and geographic distribution Black fonio is cultivated as a cereal in scattered localities from Côte d'ivoire to northern Nigeria and southern Niger, and in Cameroon. It has also been reported to be grown in Guinea and DR Congo. Black fonio is only known from cultivation. Its origin is uncertain, but it may have been derived from Digitaria ternata (A.Rich.) Stapf. Uses Black fonio is a staple food of the Birom people of the Jos Plateau in northern Nigeria and an important supplementary food to people in the Atakora mountains of Togo and Benin. It is eaten as porridge or mixed with meal of other cereals. The grain is also eaten cooked like rice or in stews. In Benin and Nigeria black fonio is made into couscous. In Togo it is used for brewing beer ('tchapalo').

56 58 CEREALSAND PULSES Properties The composition of whole black fonio grain per 100 g edible portion is: water 10.3 g, energy 1436 kj (343 kcal), protein 8.9 g, fat 3.0 g, carbohydrate 75.6 g, fibre 6.2 g, P 234 mg and Fe 10.0 mg (Leung, Busson & Jardin, 1968). The essential amino-acid content per 100 g grain is: tryptophan 215 mg, lysine 225 mg, methionine 355 mg, phenylalanine 803 mg, threonine 389 mg, valine 614 mg, leucine 1395 mg and isoleucine 508 mg (FAO, 1970). Botany Loosely tufted, erect, annual grass up to 1.4 m tall, with glabrous stems. Leaves alternate, simple; leaf sheath glabrous, smooth, striate; ligule membranous, rounded, broad, 2-3 mm long; blade linear, tapering upwards, up to 30 cm x 1 cm, glabrous except for some long hairs near the base. Inflorescence a terminal digitate panicle of (2-)4 10(-11) sessile raceme-like primary branches cm long. Spikelet up to 2.5 mm stalked, ellipticallanceolate to oblong, up to 2 mm x 1 mm, acute, glabrous, green to dark brown, 2- flowered; lower glume hyaline, minute; upper glume ovate-oblong, mm long, hyaline, 3- veined; lower floret sterile, upper floret bisexual; lemma of lower floret 7-veined, lemma of upper floret brownish to black; palea slightly shorter than lemma; stamens 3; ovary superior, with 2 stigmas. Fruit a caryopsis (grain), ellipsoid, mm x 1 mm. Digitaria iburua mainly differs from its possible ancestor Digitaria ternata by its glabrous spikelets. Digitaria iburua greatly resembles Digitaria exilis (Kippist) Stapf (fonio). It is called black fonio because of its dark spikelets, but its grain is white. Ecology Black fonio is grown at m altitude in areas with an annual rainfall of mm. It is credited with yielding a crop where fonio fails due to drought. Though it reputedly grows well on poor soils, it is planted on more fertile soils in northern Nigeria. Management The 1000-seed weight of black fonio is about 500 g. In northern Nigeria it is usually planted towards the end of June and harvested in November December. It is frequently grown intercropped with fonio, pearl millet or sorghum. Black fonio is difficult to husk and it is mostly eaten imperfectly cleaned. Genetic resources and breeding No germplasm collections or breeding programmes of black fonio seem to exist, but germplasm of 2 landraces ('Tchibam' and 'Tripka'), tentatively identified as Digitaria iburua, has been collected in Togo for the Institut Togolais de Recherche Agronomique (ITRA). Information on the genetic variation within the species and its liability to genetic erosion is not available. Prospects Black fonio is clearly less important than fonio, but is valued as a traditional cereal in some parts of West Africa. Its importance is unlikely to increase, also in view of the difficult husking. Little is known about its ecological requirements, agronomy and potential for genetic improvement, and research in these fields is recommended. Major references Burkill, 1994; Haq & Dania Ogbe, 1995; Hilu et al, 1997; Portères, 1976; van der Zon, Other references Adoukonou-Sagbadja et al., 2004; Busson, 1965; FAO, 1970; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Jideani, 1999; Leung, Busson & Jardin, 1968; National Research Council, 1996; Prasada Rao & de Wet, 1997; Stapf, ; van der Hoek & Jansen, 1996a. Authors M. Brink ECHINOCHLOAOBTUSIFLORA Stapf Protologue Prain, FI. trop. Afr. 9(4): 606 (1920). Family Poaceae (Gramineae) Chromosome number 2n = 18 Origin and geographic distribution Echinochloa obtusiflora is only known from Niger, northern Nigeria, northern Cameroon and Sudan. Uses The grains of Echinochloa obtusiflora are eaten in Sudan (Kordofan) in times of food scarcity; they are collected from the wild. Echinochloa obtusiflora is a good forage plant. Botany Erect, tufted, annual (sometimes perennial) grass up to 1 m tall; stem (culm) erect or ascending. Leaves alternate, simple and entire; leaf sheath glabrous, smooth; ligule ciliate; blade linear, cm x 2-9 mm, hairy at base and margins or glabrous. Inflorescence composed of 2 12 racemes along a central axis 5 17 cm long; racemes erect, 1-4 cm long, with spikelets in 4 rows along the rachis. Spikelet elliptical, mm long, obtuse, somewhat rough towards the tip, 2-flowered with lower floret male and upper bisexual; lower glume obtuse, about one-third as long as the spikelet, upper glume as long as the spikelet; lemma and palea of upper floret with incurved tip; stamens 3; ovary superior, stigmas 2. Fruit a

57 ECHINOCHLOA 59 caryopsis (grain). Echinochloa comprises species. It is a taxonomically difficult genus, because clear-cut boundaries between the species seldom exist and the species are very variable. Introgression between species is common. Examined strains of Echinochloa obtusiflora were partially selfincompatible. Ecology Echinochloa obtusiflora is found in shallow pools, inundation plains and other wet locations. It is a weed of rice. Genetic resources and breeding Although Echinochloa obtusiflora has a limited distribution, it does not seem liable to genetic erosion. Prospects The role of Echinochloa obtusiflora as a cereal is limited to providing some food in times of scarcity, and it is unlikely to become more important in the future. Information is lacking on the nutritional quality of the grain. Major references Burkill, 1994; Clayton, 1972; van der Zon, 1992; Yabuno, 1983; Yabuno, Other references Phillips, 1995; Stapf, Authors M. Brink ECHINOCHLOA STAGNINA (Retz.) P.Beauv. Protologue Ess. Agrostogr.: 53, 161, 171 (1812). Family Poaceae (Gramineae) Chromosome number 2n = 18, 36, 54, 63, 72, 108, 126 Synonyms Echinochloa scabra (Lam.) Roem. & Schult. (1817). Vernacular names Hippo grass, long-awned water grass, burgu grass (En). Bourgou, roseau sucré, roseau à miel du Niger (Fr). Origin and geographic distribution Echinochloa stagnina occurs throughout tropical Africa and is also found in tropical Asia, where it has possibly been introduced. Occasionally, it is naturalized in other tropical regions. Uses In tropical Africa the grains of Echinochloa stagnina are traditionally collected as a cereal, especially in times of food shortage. Echinochloa stagnina is sown as a cereal in India. The sweet stems and rhizomes have been used to produce alcoholic or non-alcoholic beverages and are still used for the extraction of sugar for making confectionery and liqueurs. Children suck the stems for the sugar. Grasslands of Echinochloa stagnina ('bourgoutières') are important dry-season grazing areas for the herds of pastoralists in West Africa. In Chad Echinochloa stagnina is sown to improve pastures; it is also sown as a fodder grass in Egypt. It can be made into hay. The stems are used for thatching and mat-making, and the leaves for caulking boats. The ash of burnt leaves has been used in the manufacture of soap and as a mordant with indigo dye. Properties Echinochloa stagnina plants in mid-bloom in Niger contain crude protein 11.3%, crude fibre 32.5%, crude fat 2.2%, nitrogen-free extracts 44.2%, Ca 0.31%, Mg 0.31% and P 0.25%. The pith of the culms contains 10% saccharose and 7 8% reducing sugars. Because of its high sugar content Echinochloa stagnina is considered an excellent fodder grass. Botany Perennial aquatic grass up to 2.5 m tall, or taller (up to10 m) when floating, with stout, often floating rhizomes; stem (culm) decumbent, with a diameter up to 2.5 cm, often spongy, rooting and branching at the lower nodes. Leaves alternate, simple and entire; leaf sheath cm long, glabrous or rarely hairy, loose at base of plant; ligule a line of hairs, often absent in upper leaves; blade linear, cm x cm, firm, with scabrid margin and filiform tip. Inflorescence composed of racemes along a central axis 6-35 cm long, erect or nodding; racemes up to 15 cm long, closely overlapping or distant, with spikelets in pairs. Spikelets narrowly ovate, mm x1-2 mm, slightly hairy but with prickly hairs on the veins, 2-flowered with lower floret male or sterile and upper bisexual; lower glume c. %of spikelet length, sharply acuminate to mucronate, upper glume as long as spikelet, awnless or with an awn up to 4 mm long; lemma of lower floret with a stout awn up to 25(-50) mm long, lemma of upper floret 3-5 mm long; stamens 3, anthers violet; ovary superior, stigmas 2. Fruit a caryopsis (grain). Echinochloa comprises species. It is a taxonomically difficult genus, because clear-cut boundaries between the species seldom exist and the species are very variable. Introgression between species is common. Echinochloa stagnina is extremely variable. Stem elongation enables Echinochloa stagnina to support a water level increase of 4 cm per day, and it can be found in water depths of up to 4 m. In the central Niger delta the biomass accumulated in the flooding season can be as high as 15-30(-40) t dry matter per ha. Stems trampled by animals and covered by soil form roots at the nodes, which is an important mode

58 60 CEREALS AND PULSES of natural regeneration of Echinochloa stagnina. Echinochloa stagnina is self-pollinating. It follows the Ci-cycle photosynthetic pathway. Ecology In tropical Africa Echinochloa stagnina occurs from sea-level up to 2300 m altitude, in shallow water, swamps and on periodically inundated clay soils. It often forms large floating mats, rooting in the mud. Echinochloa stagnina is frequently the dominant species of the natural flood-plain grasslands in the central Niger delta and the shores of Lake Chad. It may occur in massive, nearly pure stands or together with Echinochloa colona (L.) Link, Echinochloa pyramidalis (Lam.) Hitchc. & Chase and Oryza longistaminata A.Chev. & Roehr. Echinochloa stagnina is an important weed of rice in tropical Africa, the Indian subcontinent and Thailand, sometimes obstructing waterways. Management Echinochloa stagnina is propagated by seed, stem cuttings or plant division. The 1000-seed weight is about 2.4 g. Under natural conditions the seeds are shed in water. In experiments, seeds stored under water in the dark at a temperature of 20 C C showed no dormancy and had a germination percentage of almost 100%, whereas seeds kept under dry conditions had a dormancy period of 6-7 months. The dormancy is broken by removing the glumes, but this results in rapidly reduced viability. Seeds germinate within a week after sowing. In regeneration programmes in Mali seedlings or rooted cuttings are planted out into the field at densities of 10,000-16,000 plants/ha. In the central Niger delta in Mali the grains of Echinochloa stagnina are traditionally harvested using boats and by beating the inflorescences over a net. As the grains shatter easily, they are harvested at an early stage. To obtain sugar, the harvested plants are traditionally dried in the sun, after which the leaves are burnt off. The stems are washed and ground, and sugar is extracted from them by filtrating with warm water. Vegetative material for forage is cut using boats, and is eaten green or as hay. The forage is not only used locally, but also traded commercially, with an important market in Tombouctou. After the water has receded, animals are allowed to graze on the remaining plant material until the end of the dry season. Genetic resources and breeding Around 100 years ago, the 'bourgou' area in the central Niger delta was estimated at about 250,000 ha, but since then much has been replaced by rice fields. Around 1970 the area was estimated at ,000 ha. Since 1970 further reduction has taken place due to rice cultivation, reduced rainfall, reduced water levels in the river, overharvesting and overgrazing, resulting in a disturbance of traditional pastoral systems. The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, holds 9 accessions of Echinochloa stagnina. Prospects Echinochloa stagnina is a useful multipurpose plant in semi-arid regions of West Africa, especially in the central delta of the Niger river. Its area and importance have declined due to various factors, and this trend will be difficult to reverse. In many other regions Echinochloa stagnina is considered a weed, and therefore it does not seem advisable to promote it elsewhere. Information is lacking on the nutritional quality of the grain. Major references Bonis Charancle, 1994; Burkill, 1994; François, Rivas & Compère, 1989; Harlan, 1989b; Phillips, Other references Bartha, 1970; Busson, 1965; Clayton, 1989; François et al, 1991; Gibbs Russell et al., 1990; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; McKenzie et al., 1993; van der Zon, 1992; Yabuno, 1968; Yabuno, Authors M. Brink ELEUSINE CORACANA (L.) Gaertn. Protologue Fruct. sem. pi. 1: 8 (1788). Family Poaceae (Gramineae) Chromosome number 2n = 36 Synonyms Eleusine indica (L.) Gaertn. subsp. coracana (L.) Lye (1999). Vernacular names Finger millet, African millet, koracan (En). Eleusine, coracan, mil rouge (Fr). Luco, capim colonial, nachenim (Po). Mwimbi, ulezi (Sw). Origin and geographic distribution Finger millet was domesticated in the East African highlands. The oldest known archaeological remains were excavated at Axum, Ethiopia and date back an estimated 5000 years. These resemble types of highly evolved finger millet that are still grown in Ethiopia. Cultivation of finger millet spread across the eastern and southern African savanna during the expansion of iron working technology, to eventually reach South Africa some 800 years ago. In tropical Africa it is now grown from Ethiopia and Eritrea south to Mozambique, Zimbabwe

59 ELEUSINE 61 T" o? Eleusine coracana -planted and Namibia. It is also recorded from Madagascar. Finger millet is of little importance in West Africa, but is recorded from a low-rainfall zone from Senegal eastwards, especially in Niger and northern Nigeria. Finger millet reached India years ago. From India it spread across South-East Asia to China and Japan. In the United States it is grown on a small scale for bird-seed. Uses The principal use of finger millet in Africa is to provide malt for making local beer and other alcoholic or non-alcoholic beverages. In Ethiopia a distilled liquor known as 'areki' is produced from finger millet. Finger millet is also widely used as a food cereal, especially during times of scarcity. The most common use of finger millet flour is to prepare porridge, usually served with a side dish of vegetables, meat or fish. Freshly ground, slightly wet flour is made into 'cakes', which are wrapped in maize husks or banana leaves and roasted. Raw 'cakes' can be stored for several days; when needed, water is added to form a refreshing thin gruel. Flour is also pounded with bananas and the mixture is made into flat cakes that are fried in oil or baked in a dry pan. Finger millet straw is used as forage for cattle, sheep and goats. It produces excellent hay, and in India it is cultivated as a fodder grass. In Uganda the by-products of finger millet beer production are fed to chickens, pigs and other animals. Finger millet is used medicinally, e.g. the seed as a prophylaxis for dysentery. In southern Africa the juice of a mixture of finger millet leaves and leaves of Plumbago zeylanica L. are taken as an internal remedy for leprosy. Finger millet straw is used for thatching and plaiting, and in China for papermaking. In Sudan the leaves are made into string. Production and international trade In trade and production statistics, finger millet is usually combined with other millets, such as pearl millet (Pennisetum glaucum (L.) R.Br.), foxtail millet (Setaria italica (L.) P.Beauv.) and proso millet (Panicum miliaceum L.). The estimated world area of finger millet is about 3 million ha yielding about 2.5 million t of grain annually. India is the largest producer. The total area planted annually in Africa is fairly constant, and slightly less than 1 million ha. Major producers in Africa are Ethiopia, Uganda, Malawi and Zimbabwe. In Africa finger millet grain is produced for local consumption. Surpluses are sold in local markets. International trade, even among neighbouring countries in Africa, is negligible. Properties Whole grain of finger millet contains per 100 g edible portion: water 10.9 g, energy 1377 kj (329 kcal), protein 7.4 g, fat 1.3 g, carbohydrate 77.7 g, fibre 4.3 g, Ca 397 mg, P 190 mg, Fe 17.1 mg, ß-carotene traces, thiamin 0.18 mg, riboflavin 0.11 mg and niacin 0.8 mg (Leung, Busson & Jardin, 1968). The essential amino-acid composition per 100 g food is: tryptophan 107 mg, lysine 213 mg, methionine 229 mg, phenylalanine 383 mg, threonine 310 mg, valine 487 mg, leucine 701 mg and isoleucine 324 mg (FAO, 1970). Whole grain is used in grinding, resulting in a high fibre content of the flour, making it hard to digest. For food, white-coloured grain is preferred. The more bitter dark-coloured grain is preferred for beermaking. In malting, finger millet grain has a higher enzyme activity than all other major cereals except barley, making it very suitable for brewing. Finger millet straw has an in-vitro digestibility of 40-60%. Description Robust, free-tillering, tufted annual grass up to 170 cm tall; stem slender, erect or geniculately ascending, glabrous and smooth, sometimes branching, rooting at lower nodes; root system shallow, branched, fibrous. Leaves alternate, distichous, simple and entire; leaf sheath flattened, overlapping, split along the entire length; ligule 1-2 mm long, fimbriate; blade linear to linear-lanceolate, up to 75 cm x 2 cm, usually folded, scabrous above. Inflorescence a terminal digitate panicle, often with one or a few branches ('thumbs') below the main cluster of 4-19 branches ('fingers'); branches slender to robust, linear to oblong, up to 24 cm long, reflexed when slender or straight to incurved at the tip when robust,

60 62 CEREALS AND PULSES Eleusine coracana - 1, stem part with leaves; 2, inflorescence; 3, part of inflorescence branch; 4, spikelet; 5, floret without lemma and palea; 6, grain within lemma and palea; 7, grain. Source: PROSEA sometimes with secondary branches, each branch with spikelets. Spikelets ovoidellipsoid, up to 10 mm x 4 mm, mostly arranged in two rows along one side of the rachis, (3-)6-9(-12)-flowered; lower glume 1-4 mm long, with a 3-veined keel, upper glume 2-5 mm long, with a (3-)5-7-veined keel; florets bisexual, but terminal ones sometimes sterile or male, arranged in 2 opposite rows; lemma narrowly ovate, 2-5 mm long, palea slightly shorter than lemma; stamens 3; ovary superior, with 2 free styles ending in plumose stigmas. Fruit a grain with free, soft fruit wall (utricle), 4-7 per spikelet, more or less globose, up to 2 mm in diameter, white, red, brown or black; pericarp remaining distinct during development and at maturity appearing as a papery structure surrounding the seed. Other botanical information Eleusine comprises about 10 species, distributed in the tropical and subtropical parts of Africa, Asia and South America. The probable wild ancestor of finger millet is Eleusine africana Kenn.- O'Byrne (wild finger millet), commonly considered as a subspecies of Eleusine coracana (subsp. africana (Kenn.-O'Byrne) Hilu & de Wet) because it is also tetraploid (2n = 36) and crosses with finger millet produce fertile hybrids. It is an aggressive colonizer and forms large continuous populations in disturbed habitats, from where it is still harvested as a wild cereal in times of scarcity. It is a noxious weed of agriculture in Africa and invades fields of finger millet where, although predominantly self-fertilized, it occasionally crosses with the cereal to form extensively variable, weedy hybrid swarms. Primitive finger millet cultivars resemble wild finger millet in inflorescence morphology but lack the ability of natural seed dispersal. They are characterized by inflorescences with spreading branches that are straight or slightly incurved at the tip when mature. These cultivars are widespread in Africa and are also grown in southern and eastern India. A second group of highland African and Indian cultivars is also characterized by spreading inflorescence branches. Cultivars from East Africa typically have inflorescence branches that are up to 24 cm long, while others from East Africa and from southern India have cm long inflorescence branches. Cultivars from Africa commonly have more slender inflorescences than those from India, allowing the branches to become reflexed at maturity. Individuals in fields of these cultivars sometimes have their spikelets arranged in clusters along the rachis. A morphologically distinct group of cultivars is widely grown from Ethiopia to Zambia. These cultivars are characterized by spreading inflorescence branches with large, narrowly lanceolate spikelets that are arranged in two even rows along one side of the rachis. Morphologically related finger millets are grown in the mountains of eastern India, but in these cultivars the large spikelets are irregularly arranged and essentially surround the rachis. The most advanced cultivars have highly proliferated inflorescence branches that are clumped together to form a fist-like structure. These cultivars are grown across the range of finger millet cultivation in Africa and the Indian sub-continent. The most commonly grown finger millet cultivars in Africa and India have much smaller inflorescences with more or less spreading branches that may become somewhat incurved or reflexed at maturity. Growth and development Finger millet seeds lack dormancy. However, they will not germinate in soil that lacks sufficient moisture

61 ELEUSINE 63 to support seedling growth. Seedlings are sensitive to drought, but mature plants go dormant during short periods of drought and produce new tillers when conditions become favourable again. Plants tiller strongly and root from lower nodes, and provide excellent protection against soil erosion. Time from planting to flowering is days; the complete crop cycle is 3-6 months. Flowering on individual inflorescences lasts for 8-10 days and proceeds from top to bottom on branches. Finger millet is predominantly self-pollinated, with about 1% out-crossing. Heavy rain at flowering reduces seed set. Finger millet follows the C4 photosynthetic pathway. Ecology Finger millet grows best at an average temperature around 23 C. In eastern and southern Africa finger millet is grown from sea-level up to about 2500 m altitude, most commonly at m. It is mostly grown in areas with mm of rainfall during the growing season. The minimum rainfall for finger millet is mm, but below 750 mm sorghum and pearl millet are more commonly grown because of their superior drought tolerance. Finger millet is a short-day plant with a critical daylength mostly close to 12 hours. Finger millet grows on a range of soils, but prefers fertile, well-drained, sandy to sandyloam soils with reasonable water-holding capacity. It prefers a ph of 5 7, but tolerates very alkaline (ph 11) soils. It does not tolerate waterlogging. Propagation and planting Finger millet is propagated from seed. The weight of 1000 seeds is 2-3 g. Fields are prepared by hoe or animal-drawn plough. To control weeds, fields may be ploughed at the onset of rains, weeds are allowed to germinate and the fields are ploughed a second time or even as many as six times, before the cereal crop is planted. Harrowing before planting also helps to reduce weeds. Seeds are broadcast or planted in rows behind the plough. Seed rates up to 35 kg/ha may be used when the crop is broadcast; in row planting seed rates are only 3 10 kg/ha. In row planting, seeds are sown 2-3 cm deep in rows cm apart. As soon as convenient, seedlings are thinned to 5-12 cm apart within the row. In India seeds are sometimes germinated in nurseries, and the seedlings planted in the field when they are 3-4 weeks old. Although labour intensive, this practice provides fresh cereal grain well before direct-sown finger millet matures. Alternatively, finger millet may be sown or planted 1-2 weeks before the expected onset of rain. Finger millet is often intercropped with other cereals, pulses or vegetables. In Ethiopia sole cropping of finger millet is common. In Africa finger millet is grown most commonly by smallholders. Management Weeds are a major problem in finger millet, the first two weeks after germination being critical. Several rounds of manual weeding are common, requiring much labour. When finger millet is planted in rows, animaldrawn weeders are often used. Finger millet responds well to fertilizer. Recommended rates of application are kg N, kg P and kg K per ha. Smallholders, however, can rarely afford chemical fertilizers. Finger millet also responds well to the addition of organic manure or ash. In parts of Africa finger millet is grown in a shifting-agriculture system, e.g. in the 'chitemene' system in Zambia. In Kenya and Tanzania it is often grown as the first crop after clearing the land, when weed pressure is low and soil fertility relatively high. Finger millet is commonly grown in rotation with other annual crops, preferably pulses. In Uganda it is grown after tobacco or cotton. Diseases and pests Finger millet is relatively free of diseases and pests. The most serious disease is head blast caused by the fungus Magnaporthe grisea (synonym: Pyricularia grisea). It attacks finger millet across its range of cultivation. All aerial parts are affected from seedling to maturity. Serious reduction in yield occurs when inflorescences are infected during grain development. Control methods include crop rotation and the use of tolerant or resistant cultivars. Bipolaris nodulosa (synonym: Helminthosporium nodulosum) causes a dark brown leaf blight and foot and root rot, whereas Helminthosporium leucostylum causes leaf shredding, seedling blight and head blight. Insect pests include shoot fly (Atherigona soccatd), stem borers, caterpillars, grasshoppers and locusts; the phytophagous ladybird (Epilachna similis) sporadically causes serious damage. Quelea birds are pests in some areas. Major weeds of finger millet in tropical Africa include wild finger millet, Eleusine indica (L.) Gaertn. and Brachiaria deflexa (Schumach.) Robyns. These species are difficult to distinguish from finger millet in early stages of development and almost impossible to weed out successfully. The broad-leafed weed Guizotia scabra (Vis.) Chiov. is a problem in Ethiopia, but is commonly weeded out by hand. The root

62 64 CEREALS AND PULSES parasite Striga hermonthica (Delile) Benth. occurs across the range of finger millet cultivation in Africa, but rarely seems to cause serious problems. Stored finger millet is insectresistant due to the grains being too small for weevils to squeeze inside, and can be stored for several years without serious damage. Harvesting In Africa finger millet fields are often harvested in several rounds to prevent loss of grain through shattering because of uneven ripening. Harvesting usually starts when grain of the earliest genotypes contains about 10% moisture. Inflorescences are individually cut and allowed to dry. Yield The average finger millet grain yield under local practices of agriculture in tropical Africa is t/ha. With improved cultivars, optimal weed control and use of fertilizers yields of up to 5 t/ha are obtained under experimental conditions. Straw yields range from t/ha for rainfed crops to 9 t/ha for irrigated crops. Handling after harvest Finger millet grain is stored after threshing or in inflorescences that are threshed as needed. Threshing is usually by beating the inflorescences with a stick. Grain is ground on a grinding stone or in a mill. A little water may be added during the grinding process to keep the grains together and to avois fragmentation of the bran. The coarse bran is winnowed off and may be used in making beer. Straw is commonly grazed by cattle. In East Africa grain to be used in brewing is typically soaked in water and left for 2-3 days to germinate, after which the germinated seeds are ground, mixed with fried fermented maize, sorghum or finger millet flour, and placed in water to further ferment for 2-5 days. Genetic resources Major finger millet germplasm collections are being maintained and evaluated by ICRISAT Asia Center (Patancheru, India), with selected duplicate specimens at ICRISAT Southern and Eastern Africa (Bulawayo, Zimbabwe and Nairobi, Kenya) and SADC (Bulawayo, Zimbabwe). Germplasm collections include about 2800 accessions from Africa and about 2100 from Asia. Major African collections are from Uganda, Zimbabwe, Kenya, Malawi and Zambia, and most Asian collections are from India and Nepal. A large collection (about 2000 accessions, mainly from Kenya) is maintained at the National Genebank of Kenya, Muguga. Another extensive collection, numbering 1300 accessions from Ethiopia, is maintained by the Institute of Biodiversity Conservation (IBC), formerly known as Plant Genetic Resources Center of Ethiopia (PGRC/E), in Addis Ababa, Ethiopia. Germplasm from the rest of tropical Africa and tropical Asia needs to be collected. Breeding Finger millet breeders need to identify resistance to head blast and to incorporate such resistance into cultivars with acceptable yield. Screening for resistance is making progress. Progress is also being made to reduce susceptibility to lodging and shorten the growing cycle, and to increase tolerance to moisture stress and yield under traditional farming systems. Hand emasculation and pollination of finger millet florets are tedious and hamper rapid progress through trait recombination. A male sterile line has been developed in Zimbabwe. Improved cultivars released in Africa include 'Tadesse', 'Padet' and 'Boneya' in Ethiopia, 'P-283', 'P-224', 'P-221' and 'Serere-1' in Kenya, 'Engeny', 'Serere-1', 'Gulu-E' and 'P- 224' in Uganda, 'Steadfast' and 'M-144' in Zambia and 'FMV-1' and 'FMV-2' in Zimbabwe. Finger millet has limited levels of polymorphism for DNA-based markers within the cultivated and wild species. A genetic map based on restriction fragment length polymorphism (RFLP) and amplified fragment length polymorphism (AFLP) markers is being constructed using crosses between finger millet and wild finger millet. Prospects The area under finger millet cultivation varies from year to year in both Africa and Asia. The trend, however, shows stability or increases in most countries where finger millet is a staple cereal. A major constraint in finger millet production is the high labour requirement, especially for weeding, harvesting and milling. However, its excellent storage quality and the fact that in Africa it is preferred over other cereals in the production of local beer assure finger millet a place in agriculture. Major references Anand Kumar & Renard, 2001; Bisht & Mukai, 2002; Burkill, 1994; de Wet, 1995a; de Wet, 2000; de Wet et al., 1984; Hilu & Johnson, 1997; Hilu, de Wet & Harlan, 1979; Jansen & Ong, 1996; Prasada Rao & de Wet, Other references Acland, 1971; Clayton, Phillips & Renvoize, 1974; Cope, 1999; Davie & Gordon-Gray, 1977; Dida, Gale & Devos, 2001; Doggett, 1998; FAO, 1970; Harlan, de Wet & Stemler, 1976; Hilu & de Wet, 1976a; Hilu & de Wet, 1976b; Hussaini, Goodman & Timothy, 1977; Kennedy-O'Byrne, 1957; Leung, Busson

63 ERAGROSTIS 65 & Jardin, 1968; McDonough, Rooney & Serna- Saldivar, 2000; Ministry of Agriculture and Rural Development, 2002; National Research Council, 1996; Phillips, 1972; Phillips, 1995; Riley et al. (Editors), 1993; Weher, Sources of illustration Jansen & Ong, Authors J.M.J, de Wet ERAGROSTIS AETHIOPICA Chiov. Protologue Rob.-Brich., Somalia & Benadir; 726 (1899). Family Poaceae (Gramineae) Chromosome number 2n = 20 Origin and geographic distribution Eragrostis aethiopica is distributed from Eritrea, Ethiopia and Djibouti southwards to South Africa. It is also found in the southern part of the Arabian peninsula. Uses The grain of Eragrostis aethiopica is consumed in Ethiopia. In the Turkana area of Kenya the plant is eaten by cattle, goats, sheep and donkeys, but in Ethiopia it is consideredof little importance for grazing. Botany Annual grass up to 75 cm tall, erect or ascending; stem (culm) slender, solitary or tufted, often with pitted glands below the nodes. Leaves alternate, simple; leaf sheath glabrous; ligule a line of hairs; blade linear, 3-20 cm x 1-3 mm, flat or involute, glabrous. Inflorescence a loose, open, ellipsoid panicle up to 26 cm long, branches and pedicels slender and flexible, lowermost primary branches usually in whorls but sometimes solitary or paired. Spikelet linear to oblong, mm x mm, 4-9(-28)-flowered, with bisexual florets; glumes unequal, hyaline, the lower veinless and up to 0.5 mm long, the upper lanceolate, up to 1 mm long; lemma c. 1 mm long, thinly membranaceous, obtuse; palea with smooth keel; stamens 3, anthers c. 0.2 mm long; ovary superior, with 2 stigmas. Fruit a caryopsis (grain), ellipsoid, c. 0.5 mm long. Eragrostis is a large and taxonomically complex genus comprising more than 350 species mainly in tropical and subtropical regions, of which 14 are said to be endemic to Ethiopia. The diploid Eragrostis aethiopica is very similar to the tetraploid Eragrostis pilosa (L.) P.Beauv., a forage species of which the grain is sometimes eaten by humans. The former can be distinguished from the latter by its more delicate habit, smaller spikelets with blunter lemmas, smaller grain, and absence of long silky hairs in the lower panicle axis. Furthermore, Eragrostis pilosa is never glandular. In southern Africa Eragrostis aethiopica flowers from January to May. Ecology Eragrostis aethiopica is found up to 1600 m altitude in semi-desert and savanna areas on sand, silt or clay, e.g. in floodplain grassland, small vleis, pan edges and banks and beds of rivers, but also in disturbed habitats, such as roadsides and cultivated land. It is sometimes considered a weed, e.g. in Mozambique. Management Eragrostis aethiopica is collected from the wild. Genetic resources and breeding The National Genebank of Kenya, Kikuyu, Kenya, and the USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, United States, each have 1 accession of Eragrostis aethiopica. This species is widespread and in many areas common and thus not liable to genetic erosion. Prospects The role of Eragrostis aethiopica will not extend beyond being a local source of food and forage. Major references Clayton, Phillips & Renvoize, 1974; Cope, 1999; Gibbs Russell et al., 1990; Phillips, 1995; Zemede Asfaw & Mesfin Tadesse, Other references Cope, 1995; Fröman & Persson, 1974; Holm, Pancho & Herberger, 1979; IPGRI, undated; Morgan, 1981; SEPA- SAL, 2003; USDA, ARS & National Genetic Resources Program, Authors M. Brink ERAGROSTIS ANNULATA Rendle ex Scott- Elliot Protologue Journ. Bot. 29: 72 (1891). Family Poaceae (Gramineae) Vernacular names Ringed lovegrass, ring windgrass (En). Eragrostis annelé (Fr). Origin and geographic distribution Eragrostis annulata is found in Angola, Namibia, Botswana and South Africa. Uses The grain of Eragrostis annulata is eaten in Namibia. Properties Eragrostis annulata has an unpleasant smell. Botany Annual, loosely tufted grass up to 40 cm tall; stem (culm) ascending, with a glandular ring below the nodes. Leaves alternate, simple; leaf sheath thinly hairy, the slender hairs mixed with shorter gland-tipped hairs;

64 66 CEREALSAND PULSES ligule a line of hairs; blade linear, 2-12 cm x 1-5 mm, flat, thinly hairy, with scattered cratershaped glands along the margins and a lineof glandular pits along the midvein below. Inflorescence an ovoid panicle 4-20 cm long, fairly dense to open, stiffly branched, primary branches not in whorls, terminating in a fertile spikelet. Spikelet on a pedicel 1-3 mm long with a distinct annular gland, narrowly oblong or sometimes linear, laterally compressed, 3 9(-15) mm x mm, 6-16(-40)-flowered, with bisexual florets; glumes almost equal, narrowly ovate, up to 1 mm long, keeled, apex acute; lemma ovate to broadly ovate, mm long, keeled, papery, glabrous, apex obtuse; palea glabrous on the sides, persistent; stamens 3, anthers mm long; ovary superior, with 2 stigmas. Fruit a more or less square caryopsis (grain) c. 0.5 mm long, with a shallow to deep depression along the back. Eragrostis is a large and taxonomically complex genus comprising more than 350 species mainly in tropical and subtropical regions. Eragrostis annulata resembles the forage species Eragrostis cilianensis (All.) F.T.Hubb., but the latter lacks gland-tipped hairs and has a globose grain. In its native region Eragrostis annulata flowers from February to May. Ecology Eragrostis annulata is found on a range of soil types, especially on sandy, stony or calcareous soils where the groundwater table is high, and in disturbed locations. Management Eragrostis annulata is collected from the wild. Genetic resources and breeding The Division of Plant and Seed Control, Department of Agriculture Technical Service, Pretoria, South Africa, holds 2 accessions of Eragrostis annulata. This species occurs in a diversityof habitats in a fairly large region, and thus is not easily liable to genetic erosion. Prospects The role of Eragrostis annulata as a source of food is very limited and will most probably remain so. Major references Cope, 1999; de Villiers & Kok, 1988; Gibbs Russell et al., 1990; Klaassen 6 Craven, 2003; Launert, Other references IPGRI, undated; Missouri Botanical Garden, undated; USDA, ARS & National Genetic Resources Program, Authors M. Brink ERAGROSTIS NINDENSIS Ficalho & Hiern Protologue Trans. Linn. Soc. London, Bot. 2: 32 (1881). Family Poaceae (Gramineae) Synonyms Eragrostis denudata Hack. (1895). Vernacular names Perennial lovegrass, wether lovegrass (En). Eragrostis vivace (Fr). Origin and geographic distribution Eragrostis nindensis is distributed from DR Congo and Tanzania southwards to South Africa. Uses In Namibia the grain of Eragrostis nindensis is eaten. Eragrostis nindensis is a palatable pasture grass and is well utilized by sheep in particular. The young leaves are sucked to treat colds. Botany Perennial, tufted grass up to 90 cm tall, with a short oblique rhizome; stem (culm) erect, unbranched, glabrous at the nodes. Leaves alternate, simple, mainly forming a basal tuft; leaf sheath glabrous or with straight silky hairs, terete; ligule a line of hairs; blade linear, 5-30 cm x 2-3 mm, involute, rarely flat. Inflorescence a panicle 5-20 cm long, ovoid with stiffly spreading primary branches, or narrowly lanceolate and densely contracted, or linear and interrupted with the spikelets in clusters on stubby side branches, the primary branches not in whorls, terminating in a fertile spikelet. Spikelet almost sessile, ovate to narrowly oblong, strongly laterally compressed, 4 20 mm x mm, 7-30-flowered, dark yellowish green to dull grey, with bisexual florets; glumes almost equal, ovate, 1-2 mm long, keeled, glabrous, apex acute; lemma ovate, mm long, keeled, leathery, apex acute to acuminate; palea oblong-elliptical, glabrouson the sides; stamens 3, anthers mm long; ovary superior, with 2 stigmas. Fruit an ellipsoid caryopsis (grain) mm long. Eragrostis is a large and taxonomically complex genus comprising more than 350 species mainly in tropical and subtropical regions. Eragrostis nindensis is a polymorphic species, varying widely in the shape of the inflorescence and spikelet. In southern Africa Eragrostis nindensis flowers from October to June. It is a so-called 'resurrection plant', able to survive near-complete desiccation of its tissues. It retains mobile water in its leaves even when dried naturally to less than 20% water content. It also disassembles chloroplasts when too dry to maintain photosynthesis to avoid light-induced oxidative stress. Young seedlings, however, are sensitive

65 ERAGROSTIS 67 to drought. Ecology Eragrostis nindensis is found in bare, exposed or disturbed locations at m altitude, often on moist sandy and stony soils and on granite outcrops. Management Eragrostis nindensis is collected from the wild. Genetic resources and breeding The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, holds 3 accessions of Eragrostis nindensis. Prospects The role of Eragrostis nindensis as a food or fodder plant will remain limited, although its ability to survive in dry conditions offers some prospect in semi-arid and arid regions. Major references Clayton, Phillips & Renvoize, 1974; Cope, 1999; Gibbs Russell et al., 1990; Klaassen & Craven, 2003; van Oudtshoorn, Other references Balsamo et al., 2005; IPGRI, undated; Mundree et al., 2002; USDA, ARS & National Genetic Resources Program, 2001; vander Willigen et al., Authors M. Brink ERAGROSTIS PLANA Nées Protologue FL Afr. austr. ill: 390 (1841). Family Poaceae (Gramineae) Chromosome number n = 10 Vernacular names Tough lovegrass, South- African lovegrass (En). Eragrostis d'afrique du Sud (Fr). Capim choräo, capim teff (Po). Origin and geographic distribution In tropical Africa Eragrostis plana occurs in Malawi, Zambia, Zimbabwe and Mozambique. It is also found in South Africa, Lesotho and Swaziland. It has been introduced and has naturalized elsewhere, e.g. in India and Brazil. Uses The grain of Eragrostis plana is eaten as a famine food. Eragrostis plana is considered a poor grazing grass, but is utilized late in the rainy season in more arid regions. In Lesotho it is woven into hats, baskets, necklaces and bangles, and made into ropes and plaited items used in funerals. In South Africa the root is used to treat menorrhagia and impotence. Botany Densely tufted perennial grass up to 1 m tall, without rhizomes or stolons; stem (culm) erect, unbranched. Leaves alternate, simple; leaf sheath glabrous, strongly compressed, keeled; ligule a line of hairs; blade linear, cm x mm, flat or folded, glabrous, sometimes with punctate glands along the midvein. Inflorescence a narrowly oblong to narrowly ovoid panicle cm long, branches ascending or spreading; primary branches not in whorls, but sometimes loosely clustered, terminating in a fertile spikelet. Spikelet on a pedicel mm long, linear to narrowly oblong, mm x mm, flowered, with bisexual florets; glumes unequal, the lower mm long, the upper mm long, keeled; lemma mm long, keeled, membranous with prominent lateral veins, olive green; palea with slender keel, persistent; stamens 3, anthers (1-) mm long; ovary superior, with 2 stigmas. Fruit an oblong to ellipsoid caryopsis (grain) c. 1 mm long. Eragrostis is a large and taxonomically complex genus comprising more than 350 species mainly in tropical and subtropical regions. Eragrostis plana flowers from September to May. It has the C4-cycle photosynthetic pathway. Ecology Eragrostis plana occurs from m altitude in grassland on sandy soils and shallow latérite pans, in dry areas on wet soils around vleis and rivers. Its common occurrence in pastures is considered an indicator of overgrazing or too much burning. Management Eragrostis plana is collected from the wild. Genetic resources and breeding The USDA- ARS Western Regional Plant Introduction Station, Pullman, Washington, United States, holds 3 accessions of Eragrostis plana, the Royal Botanic Gardens, Kew, United Kingdom, 2 accessions. This species is common in disturbed areas and thus not liable to genetic erosion. Prospects Eragrostis plana is eaten only in times of famine and is a poor grazing grass. Therefore it is unlikely that it will become of more than minor importance in the future. Major references Cope, 1999; Gibbs Russell et al., 1990; Jacot Guillarmod, 1971; van Oudtshoorn, 1999; van Wyk & Gericke, Other references Botha, 1992; IPGRI, undated; Neuwinger, 2000; O'Reagain & Grau, 1995; Spies & Jonker, 1987; Steenkamp, 2003; USDA, ARS & National Genetic Resources Program, Authors M. Brink

66 68 CEREALS AND PULSES ERAGROSTIS TEF (Zuccagni) Trotter Protologue Boll. Soc. Bot. Ital. 1918: 62 (1918). Family Poaceae (Gramineae) Chromosome number In = 40 Synonyms Eragrostis abyssinica (Jacq.) Link (1827), Eragrostis pilosa (L.) P.Beauv. subsp. abyssinica (Jacq.) Asch. & Graebn. (1900). Vernacular names Tef, teff, teff grass (En). Tef, teff (Fr). Tef(Po). Origin and geographic distribution Tef originated in northern Ethiopia, where it is widely cultivated. Details of its domestication are unknown, but it may predate the introduction of wheat and barley to the region. Tef is perhaps descended from the closely related wild Eragrostis pilosa (L.) P.Beauv., which is a tetraploid (2n = 40) annual like tef, and which has a cosmopolitan distribution. Grain cultivation of tef has been confined mainly to Ethiopia and to some extent the highlands of Eritrea. It is also grown in northern Kenya. Small-scale commercial tef production takes place in South Africa, the United States, Canada, Australia, Europe (the Netherlands) and Yemen. Tef is grown as a forage grass, for instance in South Africa, Morocco, Australia, India and Pakistan. It has been introduced experimentally into other tropical countries, either for its grain or for hay, e.g. in other parts of East Africa and in southern Africa. It is commonly found as an escape from cultivation. Uses In Ethiopia and Eritrea tef flour is mainly used to prepare 'injera', a thin, flat, pancake-like bread, made from dough fermented for 2-3 days. 'Injera' is prepared in a Eragrostis tef - planted range of sizes and is consumed with various sauces ('wot'), based on meat or pulses. Tef flour produces the best quality 'injera': pliable, soft with glossy appearance, which does not fall apart under handling or stick to the fingers, and has a slightly sour taste. Fenugreek (Trigonella foenum-graecum L.) can be added to tef flour in a small proportion to improve the 'injera' flavour. It also increases the lysine content. Tef flour is also mixed with barley or sorghum flour to make 'injera'. Other traditional preparations from tef flour include 'kitta' (unleavened bread), 'atmit' or 'muk' (gruel), porridge and local alcoholic beverages. Several recipes that fit Western tastes have been developed from tef flour particularly in the United States, where it has found niches in the health food market and as a gourmet food. Tef flour is used as a thickening agent in a range of products, including soups, stews, gravies and puddings. In Ethiopia tef straw is used as forage, especially during the dry season. Mixed with clay it is used as plastering material for local houses and to make bricks, stoves, granaries, beds and pottery. Outside Ethiopia tef is mainly grown for hay (e.g. in South Africa) and as green fodder (e.g. in Morocco and India). In South Africa it is planted for erosion control, often in mixtures with Eragrostis curvula (Schrad.) Nees or other grasses. Production and international trade In tef was annually cultivated on 1.9 million ha in Ethiopia, which is about 30% of the total acreage of cereals in the country. With an average annual production of 1.6 million t of grain, tef constitutes 22% of the annual cereal grain production in Ethiopia. Annually, an average of 4 million t of forage (27%of national production) is produced from tef. In Ethiopia tef is grown by smallholders, mainly for the local market and home consumption. Statistics for 1997/98 and 1998/99 indicate that 1800 t of tef grain was exported each year. Though recent statistics are not available, there is an export market for this crop in the Middle East, North America and Europe, mainly for Ethiopian expatriates. Properties The composition of whole tef grain per 100 g edible portion is: water 11 g, energy 1407 kj (336 kcal), protein 9.6 g, fat 2.0 g, carbohydrate 73 g, fibre 3.0 g, Ca 159 mg, Mg 170 mg, P 378 mg, Fe 5.8 mg, Zn 2 mg, thiamin 0.3 mg, riboflavin 0.2 mg, niacin 2.5 mg and ascorbic acid 88 mg (National Research

67 ERAGROSTIS 69 Council, 1996). The essentia] amino-acid composition per 100 g edible portion is: tryptophan 146 mg, lysine 273 mg, methionine 246 mg, phenylalanine 474 mg, threonine 334 mg, valine 491 mg, leucine 724 mg and isoleucine 378 mg (FAO, 1970). Tef starch grains are conglomerates of many polygonal simple granules 2-6 lm in diameter. Their amylose content is 25-30%. The Kofler hot stage gelatinization temperature range is 68 C (onset) - 74 C (peak) - 80 C (conclusion), which is similar to that of other tropical cereal starches, but narrower than that of maize. The viscosity of the starch is considerably lower than that of maize starch, its water absorption index is higher, and its water solubility index lower. Due to the small size of its grains, tef is almost always made into a whole-grain flour (bran and germ included), resulting in a high nutrient content. The amino acid composition of tef flour is favourable and its protein is easily digestible. It is a good source of minerals, particularly Ca and Fe, and tef has been implicated in the low incidence of anaemia in Ethiopia. Tef does not contain gluten, making it a suitable substitute for wheat in foods for people with coeliac disease. Several species of yeasts and bacteria are involved in the preparation of 'injera', but little is known about their identity and relative importance. In Ethiopia, white-grained types are preferred for food, but consumption of 'injera' from red- or brown-grained types is on the rise, especially for health-conscious urban people. Tef straw is preferred by cattle over straw of other cereals, and its quality is comparable to good natural pasture. Analyses have shown a relatively high digestibility (65%), but a relatively low protein content ( %). Description Annual, tufted grass, up to 150(-200) cm tall, with a shallow, fibrous root system; stem (culm) usually erect, simple or sparsely branched. Leaves 2-6 per culm, alternate, simple; leaf sheath glabrous; ligule mm long, ciliate; blade linear, cm x cm, glabrous. Inflorescence a panicle cm long, with slender primary branches, very loose with central rachis fully exposed to very compact with central rachis completely hidden, with spikelets per panicle. Spikelet long-stalked, narrowly oblong, 4 9 mm x 1-3 mm, 2-12(-20)-flowered; florets bisexual; glumes unequal, lanceolate, acuminate, the lower mm long, the upper mm long; lemma 2-3 mm long, 3-veined, scaberulous on the keel and towards the acuminate tip, Eragrostis tef- 1, upper part of flowering culm; 2, part of inflorescence with spikelets. Redrawn and adapted by Iskak Syamsudin pale green to dark purple; palea similar to lemma, but with 2 veins; stamens 3, anthers up to 0.5 mm long, 2-celled; ovary superior with 2 stigmas. Fruit a caryopsis (grain), ovoid to ellipsoid, mm x mm, yellowishwhite to deep brown. Other botanical information Little is known on the biosystematics of Eragrostis, a large and taxonomically complex genus comprising more than 350 species mainly in tropical and subtropical regions, of which 14 are said to be endemic to Ethiopia. Tef is the only Eragrostis species cultivated for its grain. The grains of several forage species are sometimes eaten by humans, mainly as famine food, particularly Eragrostis cilianensis (All.) F.T.Hubb., Eragrostis ciliaris (L.) R.Br., Eragrostis curvula (Schrad.) Nees, Eragrostis cylindriflora Höchst., Eragrostis gangetica (Roxb.) Steud., Eragrostis pilosa (L.) P.Beauv., Eragrostis tremula Steud. and Eragrostis turgida (Schumach.) De Wild. Crossability relationships among the species are largely unknown. Hybridization of tef is a tedious process which is a disincentive to making large numbers of crossing attempts. Era-

68 70 CEREALSAND PULSES grostis tef is an allotetraploid of which the diploid progenitors are unknown. Tef cultivars have been recognized and described based on the colour of the grains and inflorescences, ramification of the inflorescences and the size of plants. For marketing purposes, tef is classified on the basis of seed colour: 'netch' (white), 'tikur/ka'y' (red-brown) and 'sergegna' (mixed). The molecular variation as determined using DNA markers (RFLP, RAPD and AFLP) is not commensurate with the morphological variation. Growth and development Germination of tef normally takes place in 3 4(-12) days after sowing. In experiments germination was above 90% at temperatures of C; no germination occurred at 10 C. A booting stage is not noticeable in tef: the inflorescences emerge suddenly from the upper leaf sheath without boot formation. The flowers open in the morning (7 9 am) in response to light and temperature. Tef is predominantly self-pollinating, with a very low degree of outcrossing (up to 1%), and pollen is set free in the early morning. In the inflorescence floral maturity starts from the top and progresses downward, whereas in the spikelet it progresses from the base upward. Seeds mature within a month after pollination. The total growth cycle from sowing to maturity is 2 5( 6) months. Tef follows the C4- cycle photosynthetic pathway. Ecology Tef is a very versatile cereal and grows in a wide range of environments, from sea-level up to 2800 m altitude. The highest yields are obtained at altitudes of m, an annual rainfall of mm, a seasonal (July-December) rainfall of mm and an average daily temperature range of C. Yields decline when the seasonal rainfall drops below 250 mm, the mean temperature during pollination exceeds 22 C, and when the growing period drops below 90 days, in which case early-maturing cultivars become necessary. Despite its shallow root system, tef is drought resistant, due to its ability to regenerate quickly after moderate water stress and to produce grain in a relatively short period. Its rapid vegetative growth and short life cycle make tef particularly suitable for areas subject to drought after short rains. Flowering in tef is delayed at long daylengths. In Ethiopia the bulk of tef production takes place during the main rainy season ('meher') between July and November. Tef is mostly grown on Vertisols (dark, heavy clay soils with well-developed horizons) and Andosols (young, shallow soils, weathered from volcanic ash under humid conditions). Vertisol-grown tef gives higher yields provided that prolonged waterlogging does not prevail and sufficient nutrients, particularly N, are available. Farmers usually alleviate the effects of waterlogging by adjusting their planting date or using surface drainage systems (furrows). Micronutrient deficiencies can also be limiting factors on Vertisols. Tef is normally grown on soils of neutral ph, but it has been observed that it tolerates soil acidities below ph 5. Differences exist between cultivars for response to saline conditions. Tef can be found as an escape from cultivation along roadsides and railway lines, and in dry grassland on sandy loam soils. Propagation and planting Tef is propagated by seed. There is no seed dormancy and germination is rapid. The 1000-seed weight is mg. A single inflorescence can produce over 1000 seeds and a single plant over 10,000 seeds. Tef seeds remain viable for several years provided direct contact with moisture and sunshine is avoided. In Ethiopia centuries-old traditional practices are used in tef production. An oxen-drawn plough ('maresha') is used to till the land, with 2-5 passes made before sowing. Studies indicate that tef can be successfully grown under reduced tillage conditions (one ploughing to bring the seeds in contact with the soil) provided non-selective herbicides are used. To enhance germination and seedling establishment on Vertisols, a firm seedbed is made by trampling with farm animals. Normally farmers sow tef by broadcasting on a moist, fine seedbed. A seed rate of kg/ha is sufficient, but farmers often use kg/ha, because it is difficult to distribute the seed evenly, the viability of farmers' own seed is reduced, and it helps to suppress weeds at early stages. The seeds are left uncovered or covered lightly by pulling branches over the field using oxen. Tef can also be drilled in rows using adjusted machinery. Row planting minimizes lodging under good growth conditions. Sole cropping is the usual practice, but occasionally early-maturing tef cultivars are used in intercropping systems, including relay- and alley-cropping. Successful in-vitro somatic embryogenesis and plant regeneration procedures have been developed, using leaf, root or seed material to initiate callus cultures on Murashige and Skoog medium. Management After crop establishment, most farmers control weeds through hand

69 ERAGROSTIS 71 weeding once or twice. Some farmers use herbicides such as 2,4-D to control broadleaf weeds, supplemented with hand weeding to remove grass weeds. On light soils the following applications are recommended: kg N and kg P per ha; on heavy clay soils kg N and kg P per ha. Tef responds to N more than to P, by producing tall plants and large amounts of biomass; as a result, high N-rates promote lodging. To reduce the risk of lodging, farmers reduce the N-application or plant tef after pulses with no additional fertilization, and they delay the planting time so that rains have stopped by heading stage. Rotation of tef with other cereals, pulses and Niger seed (Guizotia abyssinica (L.f.) Cass.) is common practice in Ethiopia. Diseases and pests A number of diseases (mainly caused by fungi) and pests are known to attack tef, but only a few are of economic importance, mostly in specific localities and production years. Among the diseases, leaf rust (Uromyces eragrostidis), head smudge (Helminthosporium miyakei) and damping off (Drechslerei spp. and Epicoccum nigrum) are the most important. Low plant densities and early sowing reduce the damage caused by leaf rust and damping off, respectively. Fungicides that control these two diseases have been identified at experimental level, although there are no known cases of field applications. Breeding for resistance has not been carried out because of limited genetic variation in resistance and the sporadic nature and environmental specificity of the diseases. No viral or bacterial diseases are known. Pests known to attack germinating tef seeds and seedlings include the Wollo bush-cricket (Decticoides brevipennis), the red tef worm (Mentaxya ignicollis), grasshoppers, ants and termites. The black tef beetle (Erlangerius niger) attacks the inflorescence. Among the weeds, annual grasses cause the biggest damage. The parasitic weed Striga hermonthica (Delile) Benth., the recently introduced invasive weed Parthenium hysterophorus L. and the cosmopolitan weed Convolvulus arvensis L. have also become problematic. Hand weeding and crop rotation, particularly with pulses, are the most common methods in dealing with these weeds in tef; the use of herbicides is very limited. Stored tef grains are not attacked by storage insects, but rodents can be a problem. Harvesting Tef is harvested 2-5(-6) months after sowing, when the vegetative parts turn yellow. Yellowing of the stalk of the spikelet is a good indicator of maturity. If harvesting is done after physiological maturity, shattering of seed is inevitable, particularly in windy and rainy conditions. In Ethiopia harvesting starts in November and continues until early January. Harvesting is done by hand using sickles. Farmers cut the plants at ground level, heap them in the field and transport them to a threshing ground. When grown for hay, tef can normally be harvested 9 12 weeks after sowing. Yield The average tef grain yield is less than 1 t/ha, but farmers using improved cultivars and recommended management practices easily get t/ha. Yields over 2.5 t/ha have been recorded from several regions in recent extension programmes in Ethiopia. In experiments, grain yields up to 4.6 t/ha have been obtained. Normal straw yields are about 3 t/ha, but straw yields up to 20 t/ha have been recorded. Handling after harvest Threshing is carried out by trampling by farm animals. Some farmers rent combines used for other cereals for threshing. Tef is stored in any locally available storage facility. Because tef is not attacked by storage insects, no chemical protection is required. Sometimes farmers even mix tef seeds with pulses to protect the latter from weevils. Tef in Ethiopia is traditionally sold in the form of grains, not as flour. The straw is piled up near farmers' houses to be fed to animals during the dry season; a small proportion may be sold. Genetic resources The Institute of Biodiversity Conservation (IBC), formerly known as Plant Genetic Resources Center of Ethiopia (PGRC/E), holds 2541 tef accessions collected from different agro-ecological regions and 1497 accessions acquired through donations and repatriations. IBC currently has no collection of the wild Eragrostis spp. The majority of the tef germplasm collections are conserved ex situ; seeds are dried to a moisture content of 3-7% and stored in laminated aluminium foil bags at 10 C for long-term and at 4 C for short-term storage. In-situ conservation and enhancement programmes are used in some regions of Ethiopia, primarily to help farmers maintain crop diversity and to protect major cultigens from extinction while improving the yield potential. Debre Zeit Agricultural Research Center, part of the Ethiopian Agricultural Research Organization (EARO), has selected 320 core-accessions that represent the phenotypic diversity of tef for genetic studies

70 72 CEREALSAND PULSES and breeding purposes. Outside Ethiopia, smaller tef collections are held in Brazil (Centro de Pesquisa Agropecuaria dos Cerrados (CPAC), Planaltina; 400 accessions), the United States (Western Regional Plant Introduction Station, USDA-ARS, Washington State University, Pullman), Germany (Federal Centre for Breeding Research on Cultivated Plants (BAZ), Braunschweig; 30 accessions) and Japan (National Institute of Crop Science, Tsukuba; 30 accessions). Breeding Major breeding work on tef has been going on at Debre Zeit Agricultural Research Center in Ethiopia since the 1960s. The main objectives have been the development of high-yielding cultivars for the major tef-growing agro-ecological zones and the improvement of resistance to lodging. Conventional breeding has not solved the lodging problem. So far 15 cultivars have been developed through direct selection from the landraces and trait recombination. A crossing technique for the crop was developed in 1974 and since then hybridization of selected parents has resulted in the release of 5 cultivars. The majority of farmers still grow landraces. Among the improved cultivars, 'Magna' (DZ ), 'Enatite' (DZ ), 'Dukem' (DZ ), 'Tseday' (DZ-Cr-37) and 'Ziquala' (DZ-Cr-358) are the most widely grown. Genotype-environment interaction is high in tef production, especially due to environmental effects on the time to flowering and maturity. Interspecific hybridization with wild Eragrostis spp. has been tried, but success was obtained only with Eragrostis pilosa; short-stature and early maturity were the favourable traits transferred to tef. Eragrostis curvula may potentially provide stalk strength and large seed size, but hybrids with tef do not set seed. Attempts are being made to construct a genetic linkage map for tef. Anther/microspore culture and subsequent breeding of double-haploid cultivars is also being attempted. Inter simple sequence repeats are more promising than other DNA-based markers for the quantification of genetic diversity and identification of tef genotypes. Prospects In Ethiopia the expansion of tef to new production areas has continued unabated, despite farmers being encouraged to cultivate other well-known cereals instead of tef. Tef cultivation has expanded to the lowland areas, where sorghum and maize cultivation has frequently failed due to severe moisture stress. Outside Ethiopia, tef cultivation has started to a limited extent in the United States and Europe, targeting immigrant Ethiopian communities and its use as a gluten-free substitute for wheat. There is reasonable optimism that, if investments are made in scientific and developmental research, tef can rise to the status of a specialty crop in developed nations. Proneness to lodging is the biggest drawback of tef; the use of appropriate machinery and agronomic practices may be temporary solutions. In the long run, biotechnological approaches - using cloned dwarfing genes from other cereals - seem necessary to arrive at non-lodging tef genotypes in the field. Increasing the inflorescence:culm ratio could also be a suitable approach, although tef straw is important too. Knowledge of the influence of environmental factors on the nutritional quality of tef andof variation in feed quality is still very limited. Major references Berhe, 1975; Deckers et al., 2001; Ebba, 1975; Ketema, 1997; Lovis, 2003; National Research Council, 1996; Phillips, 1995; Tefera, Belay & Sorrels (Editors), 2001; Tefera, Ayele & Assefa, 1995; van der Hoek & Jansen, 1996a. Other references Assefa, 2003; Assefa, Gaj & Maluszynski, 1998; Ayele et al., 1999; Bai et al, 2000; Bai et al., 1999; Bekele, Klöck & Zimmermann, 1995; Bultosa, Hall & Taylor, 2002; Clayton, Phillips & Renvoize, 1974; Cope, 1999; FAO, 1970; Gibbs Russell et al., 1990; Ingram & Doyle, 2003; Kebebew, Gaj & Maluszynski, 1998; Kedir, Jones & Mengiste, 1993; Lazarides, 1997; Lemordant, 1971a; Lemordant, 1971b; Mamo & Parsons, 1987; Mekbib, Mantell & BuchananWollaston, 1997; Tefera, Assefa & Belay, 2003; Vecchio, Simoni & Casini, 1996; Yizengaw & Verheye, Sources of illustration Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), Authors H. Tefera & G. Belay FAGOPYRUM ESCULENTUM Moench Protologue Methodus: 290 (1794). Family Polygonaceae Chromosome number 2n = 16, 32 Vernacular names Buckwheat, beech wheat (En). Sarrasin, blé noir (Fr). Trigo sarraceno, fagópiro, trigo-mourisco (Po). Origin and geographic distribution Buckwheat is native to central and northern Asia and was domesticated in south-western China

71 FAGOPYRUM 73 (Yunnan, Sichuan provinces) from wild types. For over a thousand years buckwheat has been an important subsistence and cash crop from northern India and southern China to Korea and Japan. In the early Middle Ages it was introduced into Europe and became a leading crop on poor soils and an important staple food. European emigrants introduced buckwheat in the United States and Canada. The increased use of chemical fertilizer in the beginning of the 20 th century led to an enormous decrease of the buckwheat area in Europe and North America and replacement by higher yielding crops such as rye, oats, maize, wheat, and Irish potato. Buckwheat is still important in India, China, Korea, Japan and eastern Europe. In tropical Africa (e.g. DR Congo, Ethiopia, Uganda, Zimbabwe, Réunion) and South Africa it is cultivated sporadically and it also occurs as an introduced weed. Uses The seed of buckwheat is cooked like rice or made into flour for the preparation of noodles, pancakes, porridge, cakes and biscuits. It is an ingredient in breakfast cereals. Groats is the part of the seed left after hulling. Buckwheat seed is often ground or milled coarsely, to produce broken groats. Many consumers like the coarsely milled flour which is brownish because of the high content of hull particles. At present, high fibre content is considered a favourable character, and buckwheat is gaining importance as a health food. Buckwheat has a particular taste, liked by some, rejected by others. When sieved for almost white buckwheat flour, the extraction rate is quite low (60-70%), the waste being used for fodder. Although pure buckwheat flour is sometimes used for baking bread, the absence of gluten prevents the dough from rising. It is popular for use in mixtures with wheat, barley or rye flour to improve the taste and nutritional value of bread and other foodstuffs. Up to 30% of buckwheat flour may be mixed in wheat dough for baking bread. In the Himalaya buckwheat is processed into alcoholic drinks. The seed is also fed to animals, especially pigs and chickens, and buckwheat is sometimes considered a fodder crop rather than a food crop, e.g. in southern Africa. The plants are occasionally used for silage, but must be mixed with other fodders. The tender shoots make a palatable green leaf vegetable. Honeybees in buckwheat fields produce a dark-coloured fragrant honey. The fruit hulls are used as litter in poultry houses, for stuffing pillows, as fuel or for compost. Buckwheat is grown as green manure and cover crop, e.g. in Uganda. Fresh leaves and inflorescences are used for industrial extraction of rutin, which is applied to strengthen the inner lining of blood vessels (however, it is rather the related species Fagopyrum tataricum (L.) Gaertn., which is commonly grown for rutin production). Rutin is also industrially used as a natural pigment, antioxidant, stabilizer, food préservant and absorber of UV light. In East Africa leaves are chewed or its juice is drunk against fever. Production and international trade According to FAO estimates, the average world production of buckwheat seed in amounted to 2.7 million t/year from 2.7 million ha. The main producing countries are China (1.4 million t/year from 980,000 ha), the Russian Federation (600,000 t/year from 930,000 ha) and Ukraine (320,000 t/year from 440,000 ha). Buckwheat is mainly commercialized locally. Average world export of buckwheat was only 160,000 t/year in , with as main exporter China (104,000 t/year). No production or trade statistics are available for tropical Africa. At present, buckwheat is regaining some importance in Western countries because of its excellent nutritional qualities. In Brazil, Canada, the United States and South Africa buckwheat is grown as an export crop on highly mechanized farms. Properties The composition of buckwheat seed per 100 g edible portion is: water 9.8 g, energy 1435 kj (343 kcal), protein 13.3 g, fat 3.4 g, carbohydrate 71.5 g, dietary fibre 10.0 g, Ca 18 mg, Mg 231 mg, P 347 mg, Fe 2.2 mg, Zn 2.4 mg, thiamin 0.10 mg, riboflavin 0.43 mg, niacin 7.0 mg, vitamin B mg, folate 30 ig and ascorbic acid 0 mg. The essential aminoacid composition per 100 g edible portion is: tryptophan 192 mg, lysine 672 mg, methionine 172 mg, phenylalanine 520 mg, threonine 506 mg, valine 678 mg, leucine 832 mg and isoleucine 498 mg. The principal fatty acids are per 100 g edible portion: oleic acid 988 mg, linoleic acid 961 mg and palmitic acid 450 mg (USDA, 2005). Whole buckwheat fruits are rich in fibre, the hull providing most of it. Stored flour may become rancid because of the high fat content. Buckwheat differs from true cereals in the high biological value of the protein, caused by the high content of essential amino acids, in particular lysine. Due to the absence of gluten, buckwheat is suitable for the diet of people with coeliac disease. On the other hand, buckwheat seed is considered to be one of the most important food allergens. It also contains com-

72 74 CEREALSAND PULSES pounds which can cause irritating skin disorders ('fagopyrism') mainly in sheep and pigs and occasionally in humans in case of heavy consumption and exposure to sunlight. Fagopyrism has also been observed in humans after consumption of buckwheat honey. It may also affect cattle when fed pure buckwheat silage. The flavonoid rutin is present in all aboveground plant parts (leaves, stems, inflorescence, fruit). It has antioxidative, anti-inflammatory and antihypertensive activity; it strengthens the inner lining of blood vessels, reduces cholesterol levels, protects the blood vessels from rupturing, and blood from forming clots. Botany Erect annual herb up to 120 cm tall with angular, hollow stem. Leaves alternate, simple and entire; stipules fused into a tubular, short, truncate ocrea; petiole up to 10 cm long in lower leaves, upper leaves almost sessile; blade triangular, hastate or cordate, 2-10 cm x 2-10 cm, acute, 5-7-veined from the base. Inflorescence an axillary or terminal cluster of flowers combined into false racemes. Flowers bisexual, regular, small, rose-red to white, heterostylous; pedicel slender; tepals 5, 3-4 mm long, persistent; stamens 8, alternating at the base with 8 honey glands; ovary superior, 1- Fagopyrum esculentum - 1, flowering branch; 2, flower; 3, unwinged fruit; 4, winged fruit; 5, top view of winged fruit. Source: PROSEA celled, trigonous, with 3 styles ending in headshaped stigmas. Fruit a 3-sided nutlet, mm x 3 mm, sometimes winged, grey-brown, dark brown to almost black, 1-seeded. Seed pale green turning reddish brown, slightly smaller than fruit. Fagopyrum comprises about 15 species most of them from eastern Asia. Harpagocarpus, comprising a single species, Harpagocarpus snowdenii Hutch. & Dandy from Central and East Africa, is closely related and should possibly be included in Fagopyrum. Numerous landraces and cultivars of Fagopyrum esculentum are known, differing in fruit shape, adapted to summer or winter cultivation and comprising special-purpose types for grain, fodder, vegetable or medicine. At soil temperatures above 10 C the seed germinates fast, and seedlings emerge within 7 days. The crop grows fast, reaching the full height of cm in 4-6 weeks. Flower formation starts 20 days after emergence, anthesis starts a week later and continues until complete senescence and death of the whole plant. Buckwheat is self-incompatible. Crosspollination occurs by insects, mostly bees and flies. After the onset of flowering, the vegetative organs (leaves and stems) continue to grow while fruits develop, hence seed ripening is very uneven. From the middle of the flowering period onwards, when the leaf area has reached its maximum, further growth of vegetative organs is slow, and the seed becomes the main sink for assimilates. The seed is ready for harvesting days after emergence, depending on cultivar and ecological conditions. Ecology Buckwheat is a crop of temperate and subtropical areas, but may be grown successfully at higher elevations in the tropics. In Ethiopia it is grown at about 1500 m altitude. Exact data on optimal temperatures for buckwheat cultivation are scarce, but climate descriptions indicate a range of C for day temperatures, and night temperatures 5-10 C lower. Because the leaf mass dries slowly, a dry period is required at maturity and harvest. Buckwheat is very sensitive to frost. Strong winds cause lodging during crop growth and seed shattering at maturity. Buckwheat is rather sensitive to drought because of its poorly developed root system. During flowering, drought combined with high temperatures will cause poor seed set. Much rain during the crop cycle stimulates vegetative growth, but inhibits seed setting, also because it hampers pollination by insects. Buckwheat cultivars are

73 FAGOPYRUM 75 either day-neutral or short-day plants. Buckwheat performs best on nitrogen-poor light sandy soils, from neutral to rather acid (ph 4.5-7). It is suitable for newly cleared infertile land, drained marshland, rough land or acid soils with a high content of decomposing organic matter. Buckwheat has the reputation of producing an acceptable yield on marginal, infertile land. On wet soils or soils rich in nitrogen, luxuriant growth leads to lodging, poor fruit set, considerable losses during harvest, and thus reduced yields. When used for silage or as green manure, a low seed yield is unimportant, and more biomass will be produced on wetter, heavier soils. Management Buckwheat is propagated by seed. The 1000-seed weight is g, averaging about 22 g. Before sowing, the seedbed should be finely crumbed. A firm soil at about 5 cm depth reduces drought injury and lodging. Very crusted land and heavy clay soil will result in poor field emergence. Most growers use farm-saved seed. In mechanized cultivation, seed is drilled in rows about 30 cm apart, at a depth of 2-4 cm, requiring kg of seed per ha. The crop compensates for a thin stand by branching more. Thin stands produce more inflorescences and seeds per plant. In manual cultivation, seed is broadcast, followed by harrowing to cover the seed with topsoil. Broadcasting requires kg seed more per ha than row drilling. Buckwheat is a crop with a short growing season, easily fitting in cropping patterns with cereals, root crops, pulses, and forages. It is sometimes intercropped with vegetables. Buckwheat competes well with most weeds, but some fast-growing weeds can be a problem. Some growers sow more densely on purpose, and then weed mechanically by harrowing about 4 weeks after emergence, killing most weed plants together with a number of buckwheat seedlings. The uptake of minerals per ha for a seed yield of 2 t/ha is about 45 kg N, 10 kg P and 50 kg K. Growers usually apply no organic manure and no or little chemical fertilizer, e.g kg N, 0-15 kg P and kg K. Only P and K fertilizers should be applied if there is a risk of lodging. In crop rotations with buckwheat, any crop is suitable as preceding crop provided that it does not leave much nitrogen or weed infestation. Many fungal diseases have been recorded to affect buckwheat, but they only occasionally cause serious damage. Downy mildew (Peronospora sp.), powdery mildew (Erysiphe polygoni) and Rhizoctonia root rot {Rhizoctonia sp.) are the major ones. Cultivars differ markedly in susceptibility. Several viral diseases have been recorded, but they do not cause much damage. Insect damage is rare, but grasshoppers, bean weevils, cutworms, aphids, grain moths and storage beetles may feed on the crop. The worst problem for buckwheat production is damage by birds at maturity and after harvest, when the crop is left to dry in the field. Rats are also sometimes destructive. When most (at least 75%) seed is mature and most leaves have yellowed and dropped, the crop is harvested by mowing, after which the stems are bundled and put in heaps to dry. Farmers prefer to harvest early in the morning or late in the afternoon, or even at night, when the plants are slightly damp from dew, to reduce grain shattering. The bundles are stacked alternately head-to-tail in the heaps, to reduce bird damage. If the leaves are not dry enough, they may stick together, causing problems for threshing. Combine harvesting is practised in more industrialized countries. Seed yields normally vary from t/ha, but 3 t/ha is occasionally obtained. Research has not succeeded in raising yields of buckwheat; they remain about the same as a century ago. Thorough drying to a moisture content below 16% facilitates the removal of straw fragments and immature seed. Small farmers usually thresh manually. Mechanical threshing requires careful regulation of the threshing cylinder to avoid damaging the seed. Processing starts with hulling and separation of the hulls from the groats, followed by milling. Formerly, processing was done by individual households or in small village workshops. At present, most buckwheat is processed in factories that apply advanced food technology to make specific foodstuffs. Genetic resources and breeding The largest collections of buckwheat germplasm are held in the Russian Federation (N.I. Vavilov All- Russian Scientific Research Institute of Plant Industry, St. Petersburg, 2010 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, 1495 accessions) and Canada (Agriculture Canada Research Station, Morden, Manitoba, 570 accessions). Germplasm is also available in national collections in the United States, South Africa, Japan, Korea, India, Pakistan, Nepal, Slovenia, Poland and Germany. All these countries are part of a net-

74 76 CEREALS AND PULSES work under the International Plant Genetic Resources Institute (IPGRI), responsible for characterization and documentation. There are numerous landraces and many have already been collected for selection, testing and storage in genebanks. Buckwheat is not threatened by genetic erosion. Breeding of buckwheat has been carried out in, for example, the United States, Russia, Japan, India and former Yugoslavia. Uniform, highly self-compatible diploid lines have been isolated. They revealed a severe inbreeding depression, and heterosis in Fi generations. Breeders have selected improved cultivars with higher yields, e.g. by improving the plant habit (shorter stems with reduced liability to lodging). Autotetraploid buckwheat selections show superior characters in many aspects (self-fertile, higher rutin content, increased dry matter production, improved nitrogen uptake, no seed shedding). Improvement is also expected from breeding programmes with close relatives of buckwheat such as Fagopyrum tataricum (L.) Gaertn. (Tatary buckwheat) and Fagopyrum homotropicum Ohnishi, e.g. to increase the rutin content and to increase self-compatibility. Somatic embryogenesis of buckwheat is possible using immature embryos, protoplasts, cotyledons, hypocotyls, leaf segments or stem segments as expiants. Prospects Internationally, the interest in buckwheat as a health food is increasing. With a higher price compensating for the lower yield level compared to cereals, the acreage under buckwheat may increase. It is potentially an interesting crop for marginal land in highland areas in Africa, especially as a low-input subsistence or cash crop in rotation with other crops. An interesting feature is that at the moment buckwheat is hardly affected by diseases and pests. The main disadvantages of the crop are lodging, seed shattering and low yields. Given the existing genetic variability, it is likely that breeding will result in cultivars better adapted to tropical conditions, with less lodging and seed shattering, and improved seed set, hence with higher yield levels. Major references Biacs et al., 2002; Campbell, 1997a; Grubben & Siemonsma, 1996; Ohnishi, 1998; Zeiler & Hsam, Other references Edwardson, 1996; Gumerova et al., 2003; Hedberg, 2000; Joshi & Rana, 1995; Kim et al., 2005; Kokwaro, 1993; Ohnishi & Asano, 1999; Sohn, Lee & Kim, 2003; USDA, 2005; Watt & Breyer-Brandwijk, Sources of illustration Grubben & Siemonsma, Authors P.CM. Jansen Based on PROSEA 10: Cereals. GLYCINE MAX (L.) Merr. Protologue Interpr. Herb, amboin. 274 (1917). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n - 40 Synonyms Glycine hispida (Moench) Maxim. (1873). Vernacular names Soya bean, soybean (En). Soja, soya (Fr). Soja (Po). Soya (Sw). Origin and geographic distribution Soya bean was domesticated in the north-east of China around the 11 th century BC. From there, it spread to Manchuria, Korea, Japan and other parts of Asia. Soya bean was introduced into Korea between 30 BC and 70 AD, and it was mentioned in Japanese literature around 712 AD. It reached Europe before Soya bean was introduced into the United States in 1765 and into Brazil in It is unclear when soya bean first reached tropical Africa. There are reports of its cultivation in Tanzania in 1907 and Malawi in 1909, but it is likely that soya bean was introduced during the 19 th century by Chinese traders who were active along the east coast of Africa. Nowadays, soya bean is widely cultivated in tropical, subtropical and temperate regions throughout the world. The slow distribution outside Asia is explained by the absence of soya bean specific rhizobia in the soils of other regions; the crop Glycine max-planted

75 GLYCINE 77 only developed in the United States at the beginning of the 20 th century, following the discovery of the nodulation process by scientists. Uses In tropical Africa dry soya bean seeds are boiled for use in relishes, or used in the preparation of milk substitutes and flour. A popular use of soya bean milk in Nigeria is to make a tofu-like product that is deep fried and sold as a snack or breakfast food. The flour is used as a component of bread or mixed with maize flour to make a fortified porridge ('ugali', 'sadza'). In West Africa soya bean flour is used to thicken soup and to replace a traditional flour that is made from the seed of egusi melon (Citrullus lanatus (Thunb.) Matsum. & Nakai). 'Okara' is the pulp and bran left over from making soya milk; this cake is used in almost all the same ways as soya bean flour. Soya bean seeds are dry roasted and used directly as a snack or as a coffee substitute. The seed is also milled into flour and mixed with maize meal to serve as a relief food during famine. In Asia soya bean is used in the preparation of a variety of fresh, fermented and dried food products like milk, tofu, tempeh, miso, yuba, soya sauce and bean sprouts (soya bean sprouts are meant here, and not mung bean sprouts, which are more common in Western countries, and which are often called 'germes de soja' in French). Immature soya bean seeds are eaten as a vegetable. Soya bean seed is processed to extract oil for food and for numerous industrial purposes; the crop is currently the world's most important source of vegetable oil. The edible oil enters the market as cooking oil, salad oil, margarine and shortening. Soya bean lecithins are used as emulsifier in the food industry, in pharmacy, and in the industrial production of decorating materials, printing inks and pesticides. Soya bean oil is the main commercial source of oetocopherol (natural vitamin E) and contains stigmasterol, which is used for the commercial synthesis of steroid hormones and other pharmaceutical products. The cake remaining after oil extraction is rich in protein and is an important animal feed. Uses of soya bean proteins in food include defatted flours and grits, concentrates, isolates, textured flours and textured concentrates (commonly used as meat extender). The protein is also used in the production of synthetic fibres, glues and foams. Soya bean is also grown as fodder and as green manure; it is suitable for haymaking and silaging. The leafy stems remaining after pod removal can also be used as fodder. Production and international trade According to FAO estimates, the average world production of soya bean seeds is 173 million t/year from 77 million ha (mean of ). The main producing countries are the United States (73.5 million t/year in , from 29.4 million ha), Brazil (39.0 million t/year from 15.1 million ha), Argentina (26.4 million t/year from 10.2 million ha), China (15.4 million t/year from 9.0 million ha), India (5.9 million t/year from 6.3 million ha), Paraguay (3.4 million t/year from 1.3 million ha) and Canada (2.3 million t/year from 1.0 million ha). South Africa produced 188,000 t/year from 121,000 ha. The soya bean production in tropical Africa in was 790,000 t/year from 895,000 ha, the main producers being Nigeria (439,000 t/year from 601,000 ha), Uganda (139,000 t/year from 124,000 ha) and Zimbabwe (119,000 t/year from 62,000 ha). Average world export of soya bean seeds amounted to 47.4 million t/year in , the main exporters being the United States (25.4 million t/year), Brazil (12.3 million t/year) and Argentina (4.7 million t/year). Export of soya beans from tropical Africa was only 27,000 t/year, with Zimbabwe as main exporter (11,000 t/year). The main importer was China (11.0 million t/year). Soya bean import in tropical Africa was 37,000 t/year. Average world export of soya bean oil in was 8.2 million t/year, with as main exporters Argentina (3.0 million t/year), Brazil (1.5 million t/year) and the United States (0.9 million t/year). The export of soya bean oil from tropical Africa was negligible. The main importers in were China (975,000 t/year), India (837,000 t/year), Iran (701,000 t/year) and Bangladesh (522,000 t/year). Soya bean oil import in tropical Africa in amounted to 338,000 t/year, the main importing countries being Senegal (83,000 t/year), Angola (39,000 t/year), Mauritius (25,000 t/year), Madagascar (22,000 t/year) and Zimbabwe (22,000 t/year). Average soya bean cake export amounted to 40.8 million t/year, with as major exporters Argentina (13.6 million t/year), Brazil (10.8 million t/year) and the United States (6.4 million t/year). Soya bean cake export from tropical Africa was 30,000 t/year, mainly from Zimbabwe (14,000 t year) and Zambia (12,000 t/year). The main importers were countries of the European Union. Tropical Africa imported 72,000 t/year. Soya bean is grown by smallholders in many countries of West, East and southern Africa,

76 78 CEREALS AND PULSES though normally as a minor food crop. Commercial soya bean production on large farms and estates is common in Zambia and Zimbabwe, and also in South Africa. Properties The composition of mature raw soya bean seeds per 100 g edible portion is: water 8.5 g, energy 1742 kj (416 kcal), protein 36.5 g, fat 19.9 g, carbohydrate 30.2 g, dietary fibre 9.3 g, Ca 277 mg, Mg 280 mg, P 704 mg, Fe 15.7 mg, Zn 4.9 mg, vitamin A 0 IU, thiamin 0.87 mg, riboflavin 0.87 mg, niacin 1.6 mg, vitamin BÖ 0.38 mg, folate 375 (ig and ascorbic acid 6.0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 530 mg, lysine 2429 mg, methionine 492 mg, phenylalanine 1905 mg, threonine 1585 mg, valine 1821 mg, leucine 2972 mg and isoleucine 1770 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 9925 mg, oleic acid 4348 mg, palmitic acid 2116 mg, linolenic acid 1330 mg and stearic acid 712 mg (USDA, 2004). Soya bean seeds have a protein content higher than any other pulse. The seeds have a high lysine content; the limiting amino-acid is methionine. Mature soya bean seeds are not easily digested, contain toxic compounds and have an unpleasant taste. Therefore they must be soaked and cooked for a long time before being edible, or be processed by techniques such as roasting, fermentation or sprouting. Heat-labile antinutritional factors of soya bean are trypsin inhibitors, haemagglutinins, goitrogens, antivitamins and phytates, and heatstable ones are saponins, oestrogens, flatulence factors and lysinoalanine. Yield of meal from soya bean seeds is 80% and of oil 18%. The meal contains about 50% protein. The average fatty acid composition of commercial soya bean oil is: linoleic acid 54%, oleic acid 22%, palmitic acid 10%, linolenic acid 10% and stearic acid 4%. Soya bean oil is rich in vitamin E and contains % lecithins. Soya bean seeds are always heat-treated before oil extraction, because of the presence of antinutritional compounds. Soya bean oil tends to become rancid when exposed to air or light, due to the instability of the linolenic acid. The protein and oil concentrations of soya bean are negatively correlated, and efforts to raise both simultaneously have been unsuccessful. The oil content tends to increase with increasing temperature during growth, whereas the protein content tends to decrease. Consumption of soya bean is associated with decreased risk of atherosclerosis and cardiovascular disease, although the exact mechanisms are not clear. There are also indications that soya bean has a positive effect on bone health. The relation between soya bean consumption and reduced risk of cancer is more uncertain. Description Usually erect, bushy annual herb up to 2 m tall, sometimes viny; taproot branched, up to 2 m long, lateral roots spreading horizontally to a distance of up to 2.5 m in the upper 20 cm of the soil; stem brownish or greyish pubescent. Leaves alternate, 3( 7)- foliolate; stipules broadly ovate, 3-7 mm long; petiole 2-20 cm long, especially in lower leaves; leaflets ovate to lanceolate, 3-15 cm x 2-6(-10) cm, base cuneate or rounded, apex acute to obtuse, entire, glabrous to pubescent. Inflorescence an axillary false raceme up to 3.5 cm long, often compact, densely hairy, (2-)5-8(- 35)-flowered. Flowers bisexual, papilionaceous; pedicel up to 3 mm long; calyx tubular, with 2 upper and 3 lower lobes, hairy; corolla 5-7 mm long, white, pink, purple or bluish, standard obovate to rounded, c. 5 mm long, glabrous, wings obovate, keel shorter than the wings; stamens 10, 9 fused and 1 free; ovary superior, style curved with head-shaped stigma. Fruit a slightly curved and usually compressed pod 2.5-8(-15) cm x cm, hairy, dehiscent, (1-) 2-3(-5)-seeded. Seeds globose to ovoid or rhomboid, 6 11 mm x 5 8 mm, yellow, green, brown Glycine max - 1, flowering branch; 2, fruiting branch; 3, seeds. Source: PROSEA

77 GLYCINE 79 or black, or blotched and mottled in combinations of those colours; hilum small, black, brown or yellow. Seedling with epigeal germination; cotyledons thick and fleshy, yellow or green; first leaves simple and opposite. Other botanical information Glycine comprises about 20 species distributed in the tropics and subtropics of Asia and Australia. It is divided into 2 subgenera; Glycine (perennials) and Soja (annuals), with the latter including 2 species: Glycine soja Sieb. & Zucc. (wild types, occurring in eastern Asia) and Glycine max (cultivated types). Glycine soja is considered the wild ancestor of Glycine max. The 2 taxa hybridize easily and may also be considered a single species with 2 subspecies, Glycine max (L.) Merr. subsp. max and subsp. soja (Sieb. & Zucc.) Ohashi. Numerous cultivars are recognized in tropical Asia that vary in time to maturity, size, plant habit, colour, content of oil and protein in the seed, and uses to which they are put. For oil production, yellow seeds are preferred. For immature seeds to be used as a vegetable, types with large yellow or green seeds are preferred. Hay and fodder cultivars usually have brown or black seeds and the plants often twine. In tropical Africa the older cultivars that originated from Asia tend to be tall and indeterminate in growth habit, take comparatively long to mature (about 120 days) and are 'promiscuous' in their ability to nodulate with rhizobia indigenous to African soils. These cultivars can be contrasted with soya bean cultivars that have emerged from breeding programmes and tend to be short-statured, determinate, and relatively fast-maturing (70-90 days). Growth and development Soya bean seedlings emerge within 5 15 days after sowing; a seedbed temperature of C is optimal. Flowering starts from 25 days to more than 150 days after sowing, depending on daylength, temperature and cultivar. Flowering can take 1 15 days. Soya bean is normally selfpollinated and completely self-fertile with less than 1% cross-pollination. Pollen is normally shed in the morning, before the flowers have completely expanded. At higher altitudes with lower temperatures, flowers are usually cleistogamous. The time from flowering to pod maturity is days. The total crop cycle from sowing to maturity is days. Development to maturity is usually shorter with short days than with long days. The number of pods per plant varies from a few to more than Although older literature indicates that soya bean is nodulated exclusively by slow-growing rhizobia (Bradyrhizobium spp.; initially called 'cowpea-type rhizobia') it is now well established that the fast-growing Sinorhizobium fredii can also form effective nodules with the crop. Soya bean genotypes differ enormously in their ability to nodulate with indigenous rhizobia in soils. The ability to nodulate spontaneously and prolifically with indigenous rhizobia is known as the 'promiscuous' character, compared with the 'specific' character of soya bean types that normally require inoculation with a specific type or with a few specific types of rhizobia in order to grow well. However, it has now been established that all soya bean genotypes nodulate to some extent with indigenous rhizobia, but the diversity of strains with which they can nodulate determines the extent of their promiscuity. Rates of N2-fixation in soya bean are greatest in the more luxuriant and late maturing genotypes. Studies conducted in Nigeria have measured a N2-fixation rate of 126 kg of N per ha for an uninoculated late-maturing soya bean line. Ecology Soya bean is grown from the equator to latitudes 55 N or 55 S, at altitudes from close to sea level up to 2000 m. Although the crop grows well under a wide range of temperatures, the optimum temperature for growth and development is in general around 30 C. Both excessively high (>32 C) and low (<20 C) temperatures can reduce floral initiation and pod set. Soya bean requires at least 500 mm water during the growing season for a good crop; water consumption under optimal conditions is 850 mm. Drought stress during flowering reduces pod-set but drought during podfilling reduces yield even more. Soya bean can tolerate brief waterlogging but weathering of seed is a serious problem under humid conditions. Soya bean is considered a quantitative short-day plant, but some cultivars are insensitive to photoperiod. The response to photoperiod interacts strongly with temperature, and given the relatively small variation in daylength in the tropics, temperature is the major factor influencing the rate of phenological development. The photoperiod sensitivity means that types brought directly into tropical Africa from North America will often flower and set seed before they have fully developed, restricting their yields. Soya bean grows well on most soils, except very coarse sands. The optimum ph is , and soya bean is sensitive to soil acidity, in particu-

78 80 CEREALS AND PULSES lar to aluminium toxicity. Where soya bean has not grown previously, or where P is limiting, symbiotic N2-fixation may be inadequate to meet the N requirement of the plants. Propagation and planting Soya bean is propagated by seed. The 1000-seed weight is g. The seed can be sown before the start of the rainy season, or when the soil is moist. Seed rates are kg/ha. Soya bean is sown in rows (20-)40(-75) cm apart. Within the rows, 2-3 seeds are sown in hills spaced at cm intervals, at a depth of 2-5 cm. With intercropping, sowing rates are less than for sole cropping. In traditional agriculture the land is prepared by hand or animal traction before sowing. Soya bean is grown mainly on the flat, but sowing on hills or ridges may be practised where the soil is heavy, the water table high, or rainfall heavy. Small-scale farmers in tropical Africa grow soya bean as a sole crop or in mixed cropping with maize, sorghum or cassava. Management Soya bean is usually weeded 1-3 times during the first 6-8 weeks after planting, after which its canopy should be sufficiently developed to suppress weeds. Irrigation is uncommon except for dry season production. Basal fertilization with kg P per ha is often required for adequate symbiotic N2- fixation and general growth. Soya bean is commonly grown in rotation with cereals, such as maize, rice, sorghum, wheat and finger millet, whereby all fertilizer may be applied to the cereal. Diseases and pests Various fungal diseases affect soya bean. Soya bean rust (Phakopsora pachyrhizi and Phakopsora meibomiae) is a devastating disease that can reduce yields by as much as 90%. It is widespread; in tropical Africa it is recorded from Sierra Leone, Ghana, Nigeria, DR Congo, Uganda, Tanzania and Zambia. Partial resistance has been found in various cultivars; fungicides may reduce damage. Red leaf blotch (Dactuliochaeta glycines, synonym: Pyrenochaeta glycines) is confined to Africa; it is economically important in Zambia and Zimbabwe, where yield losses of up to 50% have been recorded. Seeds are not infected, but the fungus can survive in the soil for many years. Tolerant cultivars have been developed in Zimbabwe. Frogeye leaf spot (Cercospora sojina, synonym: Passalora sojina) occurs worldwide. It is primarily a leaf disease, but it may also affect stems, pods and seeds. It survives on stored seeds and crop residues and is spread by wind. Control measures include seed treatment (e.g. with thiram), deep-ploughing of crop residues, crop rotation and application of fungicides. Resistant cultivars are available. Purple seed stain and leaf blight are caused by Cercospora kikuchii, also occurring worldwide. Recommended control measures are crop rotation, the use of clean seed, ploughing back of crop residues, spraying with fungicides and the use of tolerant cultivars. Among the bacterial diseases of soya bean, bacterial blight (Pseudomonas syringae pv. glycinea, synonym: Pseudomonas savastanoi pv. glycinea) is common wherever soya bean is grown. Control practices of this foliar disease include the use of resistant cultivars, the use of clean seed, crop rotation and burying of crop residues. Bacterial pustule (Xanthomonas campestris pv. glycines, synonym: Xanthomonas axonopodis pv. glycines) is also widespread. It is seedtransmitted and survives on crop debris. Control measures are similar to those of bacterial blight. Virus diseases of soya bean include soya bean mosaic virus (SMV), cowpea mild mottle virus (CPMMV) and bean yellow mosaic virus (BYMV), but these are of little importance in tropical Africa. Soya bean cyst nematode (Heterodera glycines) and root-knot nematodes (Meloidogyne spp.) can cause severe damage, especially on sandy soils. Therefore, soya bean should not be grown continuously or in rotation with other susceptible crops, such as tobacco. Soya bean cultivars resistant to nematodes are available. The most widespread and probably most serious pest of soya bean in tropical Africa is the southern green stink bug or soya bean green stink bug (Nezara viridula), of which the nymphs and adults feed on soya been seeds. Control is by using insecticides. The most important leaf-eating pest is probably the soya bean looper (Xanthodes graellsii). Bean flies (mainly Melanagromyza sojae and Ophiomyia centrosematis) can cause complete yield loss. Soya bean seedlings are occasionally damaged by cutworms (Agrotis spp.). No major storage pests are recorded from Africa, except rodents. Harvesting Mature seeds of early-maturing soya bean cultivars can be harvested 65 days after planting; late maturing cultivars may need more than 150 days. In tropical Africa the plants are generally allowed to dry in the field and the whole plants (above ground) are collected by hand when most leaves have turned yellow and fallen, and when the pods have turned brown. The moisture content of the seeds at harvesting should be 14-15%. Pods of

79 GLYCINE 81 older cultivars have a tendency to shatter in the field when drying and plants need to be harvested on time to prevent major loss of yield. Combine-harvesting is used on large farms and estates. Soya bean seed for vegetable use is harvested when the pods are still green but the seeds fill the pod. Yield Average world soya bean yields are 2.25 t/ha; those in the United States 2.5 t/ha. Under smallholder farming conditions in tropical Africa yields are often as low as 0.5 t/ha due to a combination of poor soil conditions and poor management. However, yields of more than 2 t/ha have been recorded on smallholder farms in Zimbabwe and Nigeria, particularly when farmers are growing soya bean as a cash crop to sell in urban food markets or for processing for oil and feed. The average yield of commercial, large-scale farmers hovers around 2 t/ha. Under optimal growing conditions yields of more than 4.5 t/ha have been recorded in Zimbabwe. In Nigeria and most of West Africa the yield potential of soya bean is about 3 t/ha. Handling after harvest The whole plants are dried in the sun. They are then threshed by beating with sticks. The seeds are winnowed, cleaned and prepared for store or market. For on-farm storage a seed moisture content of10 12% must be maintained. Deterioration of seed in storage is a major problem in the humid tropics and is attributable to poor storage conditions and pests. In the savanna region of West Africa producers have developed appropriate seed handling methods that ensure good seed germination when they save their own seeds. Genetic resources The largest germplasm collections of soya bean are held in China (Institute of Crop Germplasm Resources (CAAS), Beijing, 23,600 accessions; Nanjing Agricultural University, Nanjing, 13,000 accessions), the United States (USDA-ARS Soybean Germplasm Collection, Urbana, Illinois, 18,400 accessions) and Taiwan (Asian Vegetable Research and Development Centre (AVRDC), Shanhua, 12,500 accessions). In tropical Africa substantial germplasm collections are held in Zimbabwe (Crop Breeding Institute, Harare, 2250 accessions), Nigeria (International Institute of Tropical Agriculture (UTA), Ibadan, 1800 accessions), Rwanda (Institut des Sciences Agronomiques du Rwanda (ISAR), Butare, 550 accessions) and Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 130 accessions). Genebank accessions have been successfully used for the improvement of resistance to diseases and pests, plant morphology and seed composition. The genetic variation of soya bean cultivars is rather narrow. For instance, about 80% of the genepool of the soya bean cultivars grown in the United States can be traced to only 7-10 introductions from the same geographical area. It is therefore considered necessary to broaden the genetic base of cultivated soya bean by using wild relatives. Breeding Breeding work on soya bean in tropical Africa aims at the development of improved cultivars with high and stable seed yield, resistance to major diseases and pests, tolerance to aluminium toxicity, resistance to lodging and pod shattering, promiscuous nodulation, improved seed longevity and acceptable seed colour, oil and protein content. A breeding programme at UTA has focused since the early 1980s on combining the yield potential of cultivars bred in North America with the 'promiscuous' or 'naturally-nodulating' ability of landraces from Asia to form nodules and fix nitrogen without inoculation in African soils. This breeding programme has produced a series of excellent multi-purpose cultivars that combine a leafy growth habit with appropriate seed type and high yield potential. These cultivars are liked by smallholder farmers because they provide biomass for forage or to improve soil fertility in addition to having high seed yields. They are being actively promoted in many countries in East and West Africa at present. In southern Africa similar benefits of a largely unimproved cultivar, 'Magoye', were recognized. 'Magoye' is a leafy, indeterminate cultivar, relatively resistant to stresses and mid-season drought, that grows better on poor soils than some of the improved cultivars, nodulating well with indigenous rhizobia. Despite its smaller, yellow seed, and susceptibility to some diseases such as bacterial pustule, this makes it an attractive cultivar for use by smallholder farmers in southern Africa. Research at UTA has identified soya bean breeding lines that favour the germination of Striga hermonthica (Delile) Benth., a parasitic weed that infects maize, sorghum and pearl millet, and one of the major constraints to production of these crops in Africa. The probable cause of this effect of soya bean is the presence of root exudates. The inclusion of these soya bean cultivars in crop rotations stimulates Striga germination and reduces infestation levels in following sorghum, maize or pearl millet crops as a result of the decline of Striga

80 82 CEREALS AND PULSES seed numbers in the soil. After germination the Striga plants are unable to infest the soya bean crop, and die without producing seed. A 3-year trial conducted in Benin showed that 2 seasons of soya bean followed by maize reduced Striga hermonthica emergence by about 80-90% and increased maize yield from 1.5 t/ha to 3 t/ha. Similar results have been obtained in farmers' fields in Nigeria. As soya bean becomes more popular in areas where maize, sorghum and pearl millet are grown, the amount of damage caused by Striga hermonthica should become significantly less. A number of private seed companies are involved in breeding soya bean in southern Africa, with particular emphasis on cultivars suitable for mechanized production. The companies are targeting a number of traits including high seed yield, resistance to lodging, resistance to pod shattering, rapid stem dehydration, seed quality and resistance to diseases (particularly red leaf blotch and frogeye leaf spot). New cultivars are 'Solitaire', 'Soma', 'Soprano' and 'Viking', all of which have some resistance to frogeye leaf spot. These cultivars are all specific in their nodulation ability and require inoculation with the appropriate rhizobia. Inoculants for soya bean are produced, sold and used on a large scale in both Zimbabwe and South Africa. Soya bean is a leading crop in the field of genetic transformation. In 2001 the world area under transgenic herbicide-tolerant soya bean was estimated at 33 million ha; it was grown in the United States, Argentina, Canada, Mexico, Uruguay, Romania and South Africa. Genetic linkage maps have been constructed for soya bean on the basis of various markers (RFLP, SSR, RAPD, AFLP), and several moderate- to high-density genetic maps are now available. In-vitro regeneration of soya bean is possible through organogenesis and somatic embryogenesis. Prospects Soya bean is a relatively new crop in tropical Africa. It has long been thought that soya bean was not a suitable food crop for the region, because of the long cooking time needed and the unacceptable taste. However, the importance of the crop in tropical Africa has grown rapidly during the past decades. Especially Nigeria witnessed a rapid expansion in soya bean production in the smallholder farming sector in the savanna zone during the 1990s. The driving force for this expansion was the use of soya bean in the preparation of many traditional foods and the introduction of soya tofu which rapidly became one of the most popular snacks in markets in the region and is widely used by the food processing industry. In some areas, the low world prices may depress opportunities for local producers to respond to increased local demand for soya bean. Soya bean can play an increasingly important role in diversifying cereal-based farming systems in tropical Africa. Apart from being a source of residual nitrogen for subsequent cereal crops in crop rotations, the new multi-purpose cultivars bred by UTA provide the additional benefit that they help to reduce Striga hermonthica damage on maize, sorghum and millet, thus representing a major opportunity to provide sustainable crop rotations for smallholder farmers. It is therefore very likely that soya bean production will expand in many tropical African countries in the future. Major references Boerma & Specht, 2004; Carsky et al., 2000; Dashiell & Fatokun, 1997; Hymowitz, 1995; Javaheri & Baudoin, 2001; Mpepereki et al., 2000; Sanginga et al., 2003; Shanmugasundaram & Sumarno, 1989; Sinclair, 1998; Singh, Rachie & Dashiell (Editors), Other references Akem & Dashiell, 1996; Aljanabi, 2001; Dashiell & Akem, 1991; FAO, 1998; Giller, 2001; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hume, Shanmugasundaram & Beversdorf, 1985; ILDIS, 2005; James, 2002; Mackinder et al., 2001; Musiyiwa, Mpepereki & Giller, 2005; Rehm & Espig, 1991; Sanginga, Thottappilly & Dashiell, 2000; Sanginga et al., 1997; Sanginga et al., 1999; Shannon & Kalala, 1994; Thulin, 1989a; Tindall, 1983; USDA, 2004; Weiss, Sources of illustration Shanmugasundaram & Sumarno, Authors K.E. Giller & K.E. Dashiell Based on PROSEA 1: Pulses. HORDEUMVULGARE L. Protologue Sp. pi. 1: 84 (1753). Family Poaceae (Gramineae) Chromosome number In = 14 Synonyms Hordeum sativum Jess. (1863). Vernacular names Barley (En). Orge (Fr). Cevada (Po). Shayiri (Sw). Origin and geographic distribution Barley was domesticated in western Asia before 7000 BC. Cultivation spread to northern Africa and, moving upwards along the Nile, into Ethiopia,

81 HORDEUM 83 Hordeum vulgare - planted where it became one of the major cereals. It is not known exactly when barley reached Ethiopia, but it has been grown there for at least 5000 years. Barley reached southern Spain BC and central and northern Europe, as well as India, BC. It reached China BC. Barley was cultivated in oases in the Sahara BC, but seems not to have migrated southwards into West Africa before the 16 th Century AD. Columbus took it to the New World. Nowadays it is grown over a broader environmental range than any other cereal, from 70 N in Norway to 44 S in New Zealand. In Ethiopia, Tibet and the Andes it is cultivated higher on the mountain slopes than other cereals. In tropical Africa it is mainly found in East Africa. In West Africa barley is grown as a cold season crop in the Sahel region and northern Nigeria. In Madagascar it is grown in the dry season. Uses On a worldwide scale barley is used, in order of importance, as animal feed, for malting (especially for beer brewing) and as human food. In the tropics and subtropics it is mainly grown for human food. In Ethiopia and Eritrea most of the grain is used for making the local pancake-like bread ('injera'), but it is also made into porridge, soup and home-made alcoholic and non-alcoholic drinks. In Kenya and Tanzania it is more important for brewing. Grains are roasted or fried, and consumed as snack, particularly during social gatherings. Barley straw is used as animal feed, for animal bedding, and as cover material for huts. Barley can be grazed during tillering or cut before maturity and directly fed to the animals or used for silage. In temperate areas barley grain is also fed to animals. By-products from the brewing process are also used in livestock feed. Production and international trade Annual world production of barley is 136 million t grains (mean of ) from 54 million ha. Major producing countries are the Russian Federation, Germany and Canada with 16.2, 12.1, and 11.4 million t per year, respectively. In tropical Africa the main barley-producing country is Ethiopia, with 950,000 t of grain from 870,000 ha in , followed by Kenya (45,000 t from 20,000 ha) and Eritrea (24,000 t from 44,000 ha). In Ethiopia and Eritrea barley production is mainly for subsistence, and in Ethiopia the share of malting barley is about 2% of the total production. Small areas of barley (less than 4000 ha) are planted in Mauritania, DR Congo, Tanzania, Zambia and Zimbabwe. Most barley is consumed locally, with about 20 million t per year entering international trade in The European Union, Australia and Canada are the largest exporters; Saudi Arabia, China and Japan the largest importers. In the largest importers in tropical Africa were Zimbabwe and Ethiopia, with average annual imports of 8000 t and 3000 t, respectively. Properties The composition of barley per 100 g edible portion is: water 9.4 g, energy 1482 kj (354 kcal), protein 12.5 g, fat 2.3 g, carbohydrate 73.5 g, dietary fibre 17.3 g, Ca 33 mg, Mg 133 mg, P 264 mg, Fe 3.6 mg, Zn 2.8 mg, vitamin A 22 IU, thiamin 0.65 mg, riboflavin 0.29 mg, niacin 4.6 mg, vitamin B mg, folate 19 Xg and ascorbic acid 0 mg. The essential amino acid composition per 100 g edible portion is: tryptophan 208 mg, lysine 465 mg, methionine 240 mg, phenylalanine 700 mg, threonine 424 mg, valine 612 mg, leucine 848 mg and isoleucine 456 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 999 mg, palmitic acid 411 mg, oleic acid 241 mg and linolenic acid 110 mg (USDA, 2004). Barley cannot be used to make leavened bread because of its low gluten content. The relatively high dietary fibre content makes barley interesting from a nutritional point of view, as increased amounts of dietary fibre have been shown to help in controlling diabetes, hyperlipidaemia, obesity, hypertension, coronary heart disease and various gastro-intestinal disorders. Barley is preferred to wheat and rye for malting because of the cemented lemma and palea, which protect the young plumule during germination, produce a firmer grain at the high moisture content needed for steeping

82 84 CEREALS AND PULSES and malting, and facilitate filtering. Description Annual grass up to 120(-150) cm tall, tillering freely; root system consisting of 3 9 primary roots and adventitious roots; stem (culm) usually erect. Leaves 5-10 per culm, alternate, simple; leaf sheath glabrous, with large, overlapping auricles at apex; ligule 1-3 mm long, hyaline, ciliate; blade linear-lanceolate, 5-40 cm x cm. Inflorescence a terminal cylindrical spike 5-10(-30) cm long, with groups of 3 spikelets attached alternately. Spikelets 1-flowered, with bisexual floret; glumes narrow, about half the length of the lemma, with fine bristles at the tip; lemma ovate, 9-11 mm x 3 mm, 5-veined, usually ending in an awn up to 15 cm long; palea as long as lemma, awnless; stamens 3; ovary superior, with 2 stigmas. Fruit a caryopsis (grain), ellipsoid, flattened and grooved on one side, varying in size according to cultivar, hairy at the tip. Other botanical information Hordeum comprises 32 species. Hybrids from crosses of Hordeum vulgare with other Hordeum species are sterile or anomalous. The large variability in barley led to many barley species being distinguished in the past. At present, the accepted view is that in barley evolution only a single species is involved, Hordeum vulgare, forming a crop-weed complex, in which the cultivated Hordeum vulgare spike; 3, spikelets. Source: PROSEA 1, lower part of plant; 2, barley has been developed from original wild populations. Fertile hybrids between wild and cultivated types are easily obtained and occur naturally where the two grow together. Wild barley has been classified as subsp. spontaneum (C.Koch) Thell. (synonym: Hordeum spontaneum C.Koch), distributed in northern Africa, the eastern Mediterranean area and western Asia, and cultivated types as subsp. vulgare. The variation in cultivated barley is overwhelming, with thousands of landraces and hundreds of cultivars. Cultivars can be divided according to the number of rows of grains (2 or 6), lax and compact spikes, or awned and awnless lemmas. All wild types have 2-rowed spikes, i.e. of the 3 spikelets at each node the two lateral ones are sterile, and only the central one develops a grain. Under domestication 6-rowed types appeared in which all 3 spikelets produce grains. Here, 2 genes are involved, both with multiple allelic series, but a single recessive mutation is enough for a 2-rowed barley to become 6-rowed. Cultivars grown in West Africa have 6 rows of grains in the spike, but in Ethiopia, especially in the upper highlands, a type of barley is found with 2 full rows and parts of other rows ('irregular barley'). In 'husked barley' lemma and palea adhere to the grain at threshing, whereas in 'naked barley' the grain threshes free. A single recessive gene controls the latter character. Based on vernalization requirements barley is classified in winter and spring types. Growth and development The seedling emerges from the soil 5-6 days after germination. Tillers are produced on the main shoot until flower initiation. The number of tillers per plant is influenced by plant density, cultivar and environmental factors: a single plant usually develops 1 6 stems, but at low densities it may be several times as high. Time to flower initiation varies among cultivars, but in general barley flowers earlier than wheat. Barley is a quantitative long-day species, flowering earlier under longer photoperiods, but the photoperiod sensitivity differs between cultivars, ranging from very sensitive to almost insensitive. Flowers are predominantly self-pollinated, but cross-pollination can be as high as 10%. The grain ripens in days. Barley can mature in a short season of 3-4 months, which is shorter than the season needed for other major cereals. Ecology Barley grows under a wide range of photoperiod, temperature and rainfall condi-

83 HORDEUM 85 tions, but is best adapted to temperate climates. It withstands high temperatures in dry climates and humidity in cool climates, but it is ill adapted to hot, humid climates, primarily because of its susceptibility to diseases. In Ethiopia, barley is cultivated at m altitude, but mainly between 2000 m and 3000 m. In Kenya it is grown at m altitude. Winter barley types need vernalization by a period of low temperature (3-12 C). Barley is adapted to an annual rainfall ranging from 200 mm to more than 1000 mm. It is more droughtescaping, due to its early maturity, than drought-tolerant. Well-drained fertile loams or light clay soils are best for barley production. Barley is more tolerant of alkaline soils than other cereals, but does not tolerate acid soils; a ph of is generally acceptable. It is very sensitive to waterlogging. Some cultivars withstand up to 1% salt in the soil. Propagation and planting Barley is planted through direct seeding. The 1000-seed weight is g. Before sowing, the land is ploughed to a depth of cm. On smallholdings the land is prepared by animal traction. The seed should preferably be treated with fungicide to protect the crop from seed- and soil-borne diseases. Barley can be planted with drills, but on smallholdings seeding is usually by hand. When sowing with drills, the distance between rows is cm, and the seed rate is kg/ha. The sowing depth is 2 6 cm. In the highlands of Ethiopia, barley is cropped twice a year. The main cropping season ('mener') is from June December (with most of the rain in June-September), while the minor cropping season ('belg') is from February June (most rain in March April). Barley is the most suitable crop for 'belg'-season production. Barley is usually sole-cropped, but in Eritrea and northern Ethiopia barley is often intercropped with wheat (the 'hanfetz' cropping system). In Eritrea farmers traditionally broadcast mixtures of 67% barley and 33% wheat; sometimes 50:50 mixtures are sown. In Ethiopia and Eritrea barley is a smallholder crop, but in Kenya it is grown on large-scale mechanized farms. Management Weeds cause economic losses in barley due to a reduced number of tillers and grains per spike. Resource-poor farmers weed by hand. The most widely used herbicide to control broad-leaved weeds in post-emergence spraying is 2,4-D. Barley requires about kg N to produce 1 t of grain. Nitrogen can be applied before seeding or as topdressing after planting. Under dry conditions high rates of N application can cause yield reductions, whereas under favourable conditions high rates of N increase the risk of lodging and diseases. Excessive rates of N fertilization of malting barley may increase the protein level in the grain above the acceptable level. In Ethiopia farmers usually grow barley in lowinput systems, with minimal seedbed preparation and weeding, and without applying herbicides, fertilizers or insecticides. Low soil fertility and insufficient weed management are major constraints. In experiments at Holetta, application of 57 kg N and 25 kg P per ha led to a grain yield increase of up to 200%, whereas a single hand weeding at 35 days after emergence gave a grain yield increase of up to 20% compared to an unweeded crop. Lodging is also a common problem in Ethiopian barley cultivation. In West Africa barley is grown as a dryseason crop, often under irrigation. Diseases and pests Barley is affected by several viral and fungal diseases. The most important viral diseases are barley yellow dwarf virus (BYDV), transmitted by various aphid species, and barley stripe mosaic virus (BSMV), transmitted through seed or plant contact. Control measures for BYDV include the use of tolerant or resistant cultivars and aphid control, whereas BSMV can be controlled by using virus-free seed and resistant cultivars. Epidemics of African cereal streak, caused by maize streak virus (MSV) and transmitted by leafhoppers (Cicadulina spp.), have occurred in Kenya. Important fungal diseases include powdery mildew (Blumeria graminis f.sp. hordei, synonym: Erysiphe graminis f.sp. hordei), spot blotch (Bipolaris sorokiniana, synonym: Helminthosporium sativum), scald (Rhynchosporium secalis f.sp. hordei), scab (Fusarium spp.), rusts (Puccinia spp.), net blotch (Pyrenophora teres), barley stripe (Pyrenophora graminea) and smuts (Ustilago spp.). In Ethiopia and Eritrea, scald, blotches and rusts are the most important fungal diseases; the use of resistant cultivars is often the most effective control measure. Other control measures include crop rotation, the use of clean seed, seed treatment, fungicides, the destruction of infected plant material and deep ploughing. Several nematodes can parasitize barley: cereal cyst nematodes (Heterodera spp.), root-knot nematodes (Meloidogyne spp.), root-gall nematode (Subanguina radicicola) and root-lesion nematodes (Pratylenchus spp.).

84 86 CEREALS AND PULSES Control measures include crop rotation and fallow. Resistance breeding and the use of fungal pathogens have been successful against cereal cyst nematodes. Barley is susceptible to attack by many kinds of pests, including aphids, shoot flies, grasshoppers, crickets, thrips, army worms, cutworms, and beetles and their larvae. Control may involve adjusting the planting date, and applying insecticides. In general, losses due to pests are relatively limited, with many of the pests causing greater damage as vectors of viruses, notably BYDV. Major storage pests of barley are insects and rodents. Harvesting Barley is ready for harvesting after reaching 35-40% kernel moisture. The crop is harvested by hand using a sickle or by combine. Threshing of malting and 'naked' barley requires special care to avoid too much broken seed. Yield Barley yields vary from 0.3 t/ha in dry years and in marginal environments to 10 t/ha in high input agriculture. In Africa average yields are t/ha. In Asia and South America average yields are t/ha, in North America 2.9 t/ha and in Europe 4 t/ha. Straw yields are equally important in many developing countries, but yield statistics are not available. Handling after harvest A high moisture content of barley grains at harvest favours the development of mycotoxins dangerous to humans and livestock. Before storing, grain has to be dried to 14% moisture or less. When barley is cultivated on small areas, it is common practice to keep selected spikes to provide the seed for the next crop. Genetic resources Current barley germplasm collections at ICARDA (International Center for Agricultural Research in the Dry Areas, Aleppo, Syria) contain more than 25,000 accessions. Since 1989 the 'International Barley Core Collection' has been developed by an international consortium including ICARDA. Many national programmes maintain their own working collections. The Institute of Biodiversity Conservation (IBC, Addis Ababa, Ethiopia) has a collection of more than 12,500 accessions. Smaller collections in sub-saharan Africa are held in South Africa (National Department of Agriculture, Pretoria; Small Grain Institute, Bethlehem), Madagascar (Département de Recherches Agronomiques de la Republique Malgache, Antananarivo) and Kenya (National Genebank of Kenya, KARI, Kikuyu, Muguga). Barley shows orthodox storage behaviour. Breeding In barley breeding methods are used that are typical for self-pollinated crops. Until 1950 the main breeding method was either mass selection or pure line selection within landraces, which are still cultivated today in many countries, e.g. Ethiopia. New variability has been created by crossing, backcrossing and mutation. Recurrent selection is applied to increase recombination by crossing among Frs and by repeating the crosses among a number of F2 plants or by using male-sterility genes. Mutation breeding with radiation or chemicals and double haploids have been widely used in barley breeding. Among the International Centres, ICARDA has the global mandate for assisting barley improvement programmes of National Agricultural Research Systems (NARS) in developing countries. Modern breeding has resulted in barley types with improved amino-acid composition (4.1% of the protein as lysine). The major emphasis is on producing cultivars resistant to diseases and pests and with adaptation to specific agro-ecological environments. Resistance to aphids has been incorporated into some cultivars. Ethiopian barley has been particularly useful in the improvement of nutritional quality and in supplying resistance to fungal and viral diseases (including powdery mildew, smuts, rusts, net blotch, scald, BYDV and BSMV). In Ethiopia, 9 improved barley cultivars were released between 1980 and 2000, but the adoption level is low (11% of the area). The first genome-wide maps of barley were published in 1991, and more than 40 genomewide maps have now been published. Prospects In general large improvements in barley production are possible through breeding of cultivars resistant to lodging and diseases. As most barley breeding has been for favourable environments, the potential of the crop in low-input agriculture is largely underexploited. In the Ethiopian highlands, where barley is the preferred food crop, soil fertility has declined as a result of erosion and continuous cultivation. Under these circumstances it has been difficult to improve the locally adapted farmers' cultivars. The staple Ethiopian cereal tef (Eragrostis tef (Zuccagni) Trotter), is taking over from barley as a result of favourable market prices, and high-yielding 6- rowed barley cultivars are becoming less important. In these areas breeding for earlymaturing cultivars with higher resistance/tolerance to moisture stress than the existing

85 LATHYRUS 87 ones might reverse the trend. Ethiopia has the potential to meet the local demand for malt barley and to produce for the African market. This can be achieved with the breeding and production of high-quality malt barley that meets the breweries' standards, a concomitant increase in the number and capacity of maltprocessing factories, and an efficient market structure. Major references Ceccarelli & Grando, 1996; Gebre & van Leur (Editors), 1996; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Harlan, 1995; Hockett, 2000; Mathre, 1997; Nevo, 1992; Rasmusson (Editor), 1985; Slafer et al, 2002; von Bothmer, Jacobsen & Baden, Other references Asfaw, 1990; Aw-Hassan & Shideed, 2003; Berhane, Yitbarek & Fekadu : 1995; Briggs, 1978; Burkill, 1994; Clayton. 1972; Engels, Hawkes & Worede (Editors) 1991; Launert, 1971; National Research Coun cil, 1996; Phillips, 1995; Purseglove, 1972: Rehm & Espig, 1991; Sharpley, 1988; Tarekegne, Gebre & Francis, 1997; Thomas, 2003 USDA, 2004; von Bothmer et al, 2003; Williams, 2003; Woldeamlak, 2001; Yirga, Alemayehu & Sinebo (Editors), Sources of illustration Ceccarelli & Grando, Authors S. Ceccarelli & S. Grando Based on PROSEA 10: Cereals. LATHYRUS SATIVUS L. Protologue Sp. pi. 2: 730 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 14 Vernacular names Grass pea, chickling pea, chickling vetch, white pea (En). Gesse, gesse blanche, gesse commune, pois carré, lentille d'espagne (Fr). Chicharo, chicharo comun, sincho (Po). Origin and geographic distribution The origin of Lathyrus sativus is unknown. Records exist of wild Lathyrus sativus plants in Iraq, but it is not clear if these are truly wild or escapes from cultivation. Lathyrus sativus is perhaps a derivative from Lathyrus cicera L., which occurs wild in southern Europe, northern Africa and western Asia and is sometimes grown there. Domestication of grass pea probably took place in the Balkan around 6000 BC. Remains of Lathyrus sativus dating back to BC have been recorded from In- Lathyrus sativus -planted dia. Nowadays grass pea is widely cultivated in large parts of Asia (especially Bangladesh, India, Nepal, Pakistan and the Middle East), southern Europe and northern Africa, and to a lesser extent in America, Australia and South Africa. In tropical Africa it is mainly grown in Ethiopia, but also in Sudan, Eritrea, Kenya, Tanzania, Angola and Mauritius. Uses In Ethiopia and Eritrea grass pea seeds are mainly consumed in the form of sauces ('wot'); 'shiro wot' (sauce made of flour) and 'kik wot' (sauce made of hulled split seeds) are eaten together with 'injera' (a pancake-like unleavened bread). Boiled grass pea seeds ('nifro') are also consumed in most areas, whereas 'kitta' (an unleavened bread) made from grass pea seeds is consumed mainly during times of acute food shortage. In India the seeds are sometimes boiled whole, but are most often processed into dhal. The flour, made by grinding either the whole or split seeds, is sold as 'besan'. In Bangladesh 'roti' made out of grass pea flour is a staple for landless labourers. In India grass pea is sometimes used to adulterate more expensive pulses, such as chickpea or pigeon pea. Care should be taken in the consumption of grass pea seeds, as excessive consumption leads to a neurological disorder in people and animals, called lathyrism and characterized by paralysis of the lower limbs. In many countries grass pea seeds are used as animal feed, e.g. as an ingredient in pig starter and grower diets. In Asia immature pods are cooked and eaten as a vegetable, or are boiled, salted and consumed as a snack. Young vegetative parts are cooked as a green vegetable; they are also dried for off-

86 88 CEREALS AND PULSES season use as a vegetable. Young grass pea plants are used as fodder for cattle or for grazing in many countries. The stems and chaff remaining after harvest are often the most important reason for growing the crop in Asia. As fodder, the plants can be eaten green or as hay; they are not suitable for silage. Grass pea is grown as a green manure, e.g. in Australia and Canada. Oil from the seeds is used medicinally as a powerful cathartic. Production and international trade According to estimates India produced about 0.8 million t grass pea seeds per year from 1.5 million ha in the mid 1990s, whereas production was lower in Bangladesh (175,000 t from 240,000 ha) and Pakistan (45,000 t from 130,000 ha). In the late 1990s production in Ethiopia was estimated at 105,000 t from 142,000 ha. As a food grain, grass pea is traditionally traded within the region of production, and it does not enter international trade. Properties The composition of whole grass pea seed per 100 g edible portion is: water 8.4 g, energy 1457 kj (348 kcal), protein 27.4 g, fat 1.1 g, carbohydrate 59.8 g, fibre 7.3 g, Ca 127 mg, P 410 mg and Fe 10.0 mg (Leung, Busson & Jardin, 1968). Grass pea is highly deficient in methionine and tryptophan. Raw whole seeds contain 41% starch on a dry matter basis; the starch granules are oval and on average 25 (im long and 17 (xm wide. The neurological disorder lathyrism is caused by the water-soluble non-protein amino acid ODAP (ß-N-oxalyl-L-a,ß-diaminopropionic acid), also known as BOAA (ß-N-oxalylamino-Lalanine) and OAP (L-3-oxalylamino-2-aminopropionic acid). ODAP is present in all parts of the plant and affects various parts of the central nervous system, disrupting neurotransmission and thus impairing muscular activity. The onset of lathyrism can be slow or sudden, and is often indicated by a feeling of heaviness and pain in the lower limbs. Lathyrism is often irreversible, but not fatal. Lathyrism seems to occur when food ratios containing at least 25% grass pea are consumed continuously over months and may then affect up to 5% of the population. Outbreaks of lathyrism often occur during near-famine conditions that force people to rely too heavily on grass pea. The ODAP content of grass pea seeds typically ranges from (-2.5) g per 100 g seed. ODAP levels are not only genetically determined, but also highly influenced by growing conditions. In general, soaking and boiling reduce ODAP levels in the seeds, and this effect is enhanced if water is changed after soaking and during cooking. When the seeds are ground into flour, which is then used in baking or cooking, ODAP may not be removed. Unfortunately, effective detoxification treatments often also result in decrease of nutritional quality. Other antinutritional factors in grass pea include trypsin inhibitors, tannins, lectins, phytate and oligosaccharides. Grass pea hay contains: water 14.6%, protein 9.9%, fat 1.9%, fibre 36.5%, nitrogen-free extract 31.0% and ash 6.1%. The seeds of cultivars with up to 0.22 g ODAP per 100 g seed could be included in the diets of growing chicks at a rate of 400 g grass pea seeds per kg feed without negative effects on weight gain or fat or protein digestibility. Description Much-branched, erect, straggling or climbing, glabrous annual herb; stem slender, quadrangular, winged, up to 90( 170) cm long; taproot well-developed. Leaves alternate, 2- or 4-foliolate, ending in a simple or branched tendril; stipules prominent, leaf-like, narrowly triangular, with a smaller but similarly shaped basal appendage and often with a small tooth between the lobes; petiole mostly Lathyrus sativus - 1, flowering and fruiting branch; 2, seeds. Source: PROSEA

87 LATHYRUS 89 winged, (l-) (-3.5) cm long; leaflets sessile, narrowly elliptical-oblong, (3-)4-5(-7.5) cm x 3-5(-13) mm, cuneate at base, acute or acuminate at apex. Flowers solitary in leaf axils, bisexual, papilionaceous, pedicel with joint, lower part (l-)3-3.5(-5) cm long, upper part (2 )5 7( 8) mm long; calyx campanulate, tube c. 3 mm long, lobes 5, almost equal, narrowly triangular, 3-6 mm long; corolla blue, reddish-purple, red, pink or white, standard erect and spreading, very broadly obovate, c. 15 mm x 18 mm, clawed, retuse at top, wings broadly obovate, c. 14 mm x 8 mm, clawed, with auricle, keel slightly twisted, boat-shaped, c. 10 mm x 7 mm, clawed, with 2 auricles; stamens 10, 9 united and 1 free; ovary superior, sessile, c. 6 mm long, style abruptly upturned, c. 7 mm long, stigma spoon-shaped. Fruit an oblong, flattened pod (1.5-) (-5.5) cm x cm, upper margin 2-winged, shortly beaked, glabrous, (l-)2-5(-7)-seeded. Seeds wedge-shaped, 4 7 mm in diameter, white, pale green, grey or brown, marbled; hilum elliptical. Seedling with hypogeal germination. Other botanical information Lathyrus comprises about 150 species, mainly in the temperate regions of the northern hemisphere and South America, with a few species in Africa. Lathyrus sativus is placed in section Lathyrus along with about 30 other annual or perennial species. Based on crossability and cytological evidence, Lathyrus amphicarpos Gouan and Lathyrus cicera L. have been placed in the secondary gene pool of grass pea. More recently, successful crosses between Lathyrus sativus and Lathyrus pseudocicera Pamp. have been made. Apart from Lathyrus sativus, other Lathyrus species cultivated in Ethiopia are the ornamental Lathyrus odoratus L. and the forage Lathyrus aphaca L. Infraspecific classification is mainly based on colour of flowers, markings on pods and size and colour of seeds. In general, white seed is most popular for human consumption. The level of infraspecific variation for RAPD markers is low compared to other grain legumes such as lentil and pea. Based on isozyme analysis variation was found to be highest in western Asia and northern Africa. Growth and development Germination of grass pea seeds is most rapid around 20 C. Flowering time is months after sowing. The floral biology of grass pea favours selfpollination (anthers usually dehisce before full opening of the flower), but there are many records of substantial outcrossing (up to 28%). Total crop duration is 3-6 months. Grass pea effectively nodulates with Rhizobium leguminosarum. Ecology Grass pea is grown successfully in regions with an average annual rainfall of mm/year and an average temperature of C. It withstands heavy rains in early growth stages and prolonged drought during grain-filling. It grows well in the subtropics as a winter crop. Grass pea can be grown on a wide range of soil types, including poor soils and heavy clays. It tolerates waterlogging and moderate salinity. In Ethiopia grass pea is often grown in the dry season on residual soil moisture in heavy black clay soils at m altitude. In India grass pea is grown as a cold-season crop up to 1200 m altitude. Propagation and planting Grass pea is propagated by seed. The 1000-seed weight ranges from g. In Ethiopia it does not require a fine seedbed; 1-2 ploughings are enough. The average seed rate is normally kg/ha for a sole crop, and about 35 kg/ha when intercropped. Seeds that may have been soaked in water overnight are broadcast or drilled in furrows. Plant densities of 200, ,000 plants/ha are common for grass pea. In Ethiopia grass pea is usually sown in September-November and harvested in January- April. Grass pea is grown as a sole crop or intercropped, e.g. with barley, linseed or chickpea. In many countries grass pea is produced in rice-based cropping systems before the rice crop or alternately with a rice crop. In India grass pea is often grown as a relay crop: it is broadcast into a standing rice crop about 2 weeks before the rice harvest and left to grow on the residual moisture. Management Grass pea often receives hardly any attention after sowing, although for optimum yields it should be kept reasonably free from weeds. In a well-prepared field, the crop comes up as a thick mass over the entire surface, smothering out weeds. Grass pea is not normally fertilized, but atmospheric nitrogen fixation rates of kg/ha have been recorded. In Ethiopia grass pea is grown in rotation after barley or sometimes after a pulse crop, such as pea or chickpea, which has been sown in April and harvested in July. Diseases and pests The main diseases of grass pea are powdery mildew (Erysiphe pisi) and downy mildew (Peronospora spp.), but the latter not in Ethiopia. Rust (Uromyces fabae) and Fusarium wilt (Fusarium oxysporum) have

88 90 CEREALSAND PULSES been recorded from Ethiopia. Faba bean necrotic yellows virus (FBNYV) has been observed on grass pea in Ethiopia; it is transmitted by the aphids Acyrtosiphon pisum and Aphis cracciuora. In host-range studies grass pea was found to be susceptible to pea seedborne mosaic virus (PSbMV). Insect pests of grass pea include aphids and thrips. The pea aphid (Acyrthosiphon pisum) is the main pest of grass pea in Ethiopia. Harvesting Harvesting of grass pea should be done when leaves turn yellow and pods turn grey, to avoid shattering. The plants are pulled out by hand or cut with a sickle near the base. They are then stacked and allowed to dry for 7-8 days in the field or on the threshing floor. Yield The average seed yield of grass pea is kg/ha; in Ethiopia it is about 700 kg/ha. Yield trials conducted recently in various countries recorded yield levels of kg/ha. Handling after harvest Grass pea pods are threshed by animal trampling or by beating with sticks, after which the seed is winnowed and cleaned. The seeds may be dried for a few days before storage. Genetic resources ICARDA (Aleppo, Syria) holds a Lathyrus collection of about 1880 accessions, of which 1560 belong to Lathyrus sativus. Large grass pea germplasm collections are also kept in France (IBEAS, Laboratoire d'ecologie Moleculaire, Université de Pau; 1810 accessions), Australia (Australian Temperate Field Crops Collection, Horsham, Victoria; 844 accessions), Russia (N.I. Vavilov All- Russian Scientific Research Institute of Plant Industry, St. Petersburg; 688 accessions), Bangladesh (Plant Genetic Resources Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur; 584 accessions) and the United States (USDA/ARS Western Regional Plant Introduction Station, Pullman, Washington; 248 accessions). In tropical Africa germplasm collections are kept in Ethiopia (197 accessions at the Institute of Biodiversity Conservation, Addis Ababa; 13 accessions at the International Livestock Research Institute (ILRI), Addis Ababa) and Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu; 4 accessions). Grass pea seeds show orthodox seed storage behaviour. Breeding The major objective in grass pea breeding is reduction of ODAP levels, which is the most feasible method of producing a safe crop. Secondly, increasing the genetic yield potential is an important goal. Other breeding objectives are the incorporation of disease resistance and increase of seed size, earlier maturity and a higher harvest index. Lines with moderate resistance to powdery mildew have been identified. In Ethiopia a large number of accessions and breeding lines introduced from ICARDA are resistant to powdery mildew. Improvement has been slow in grass pea. Highyielding improved cultivars low in ODAP and with resistance against biotic and abiotic stresses have not been released in Africa. Some attempts to provide improved cultivars with low ODAP content have been made in India. In Chile and Bangladesh some promising lines have also been identified with low ODAP and high yield. Recently, of the 13 lines with low ODAP content identified in Ethiopia, three lines introduced from ICARDA have consistently shown low ODAP and reasonable yield over three years. However, the substantial outcrossing rate in grass pea has limited the progress in identifying stable lines with low ODAP content; seeds of selected lines must be multiplied in isolation and be provided to farmers every year. Indirect somatic embryogenesis (from callus) is possible in grass pea using shoot tips, axillary buds, and stem, leaf and root expiants. Direct somatic embryogenesis has been achieved from immature leaflets and nodal segments. Somaclones with low ODAP combined with high yield have been developed. Other biotechnological approaches applied in breeding for low ODAP grass pea types include incorporation into grass pea of ODAP-degrading genes from microbes, and application of antisense technology to silence the genes involved in the biosynthesis of ODAP. Transgenic grass pea plants have been produced using bombardment of expiants with DNA-coated particles. Genetic linkage maps of the Lathyrus sativus genome have been developed using various molecular markers (RAPD, STMS and STS/CAPS), and quantitative trait loci associated with resistance to ascochyta blight (Mycosphaerella pinodes) have been located for possible future transfer of this trait into the closely related Pisum sativum L. Prospects Grass pea is the least preferred among the common food legumes, but it has a number of features that make it attractive particularly to resource-poor farmers, because of its adaptation to harsh conditions such as drought and waterlogging. Therefore, grass pea is a useful crop for dry and poor soils and a

89 LENS 91 rescue crop when other crops have failed. However, the presence in the seeds of the toxin ODAP is a serious disadvantage, as it poses a real danger to the health of consumers. Cultivation of grass pea is often discouraged or has sometimes even been forbidden, e.g. in certain states of India, but this has not been successful due to the absence of cheap alternatives. The first priority in grass pea breeding therefore is the development of high-yielding cultivars with low ODAP content, which can safely be consumed. Also, more research is needed on effective detoxification methods without reducing the nutritional value of the seeds. Major references Campbell, 1997b; Campbell et al, 1994; Jansen, 1989a; Kay, 1979; Kearney & Smartt, 1995; Kislev, 1989; Knight (Editor), 2000; Muehlbauer & Kaiser (Editors), 1994; Smartt, 1984; Westphal, Other references Akalu et al., 1998; Barna & Mehta, 1995; Chowdhury & Slinkard, 2000; Croft, Pang & Taylor, 1999; Dadi et al, 2003; Getahun, Lambein & Vanhoorne, 2002; Getahun et al., 2002; Hanbury et al., 2000; ILDIS, 2002; Leung, Busson & Jardin, 1968; Mehta, Ali & Barna, 1994; Mehta & Santha, 1996; Mondai et al., 1998; Rotter, Marquardt & Campbell, 1991; Skiba, Ford & Pang, 2004 Spencer, 1994; Tekle Haimanot et al, 1993 Thulin, 1989a; Wuletaw & Endashaw, 2003 Yunus & Jackson, Sources of illustration Jansen, 1989a. Authors S.S. Yadav &G. Bejiga LENS CULINARIS Medik. Protologue Vorles. Churpfälz. Phys.-Okon. Ges. 2: 361 (1787). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceace) Chromosome number In 14 Synonyms Lens esculenta Moench (1794), Vicia lens (L.) Coss. & Germ. (1845). Vernacular names Lentil, common lentil (En). Lentille, lentillon (Fr). Lentilha (Po). Mdengu (Sw). Origin and geographic distribution Lentil is one of the oldest pulse crops and of ancient cultivation in western Asia, Egypt and southern Europe. It probably originated in western Asia, from where it spread into the Mediterranean region, Asia, Africa and Europe. Lentil was a common part of the diet of the ancient Greeks, Jews and Romans and was the mainstay of the poor, especially in Egypt. It was Lens culinaris -planted associated with many legends, tales and customs, and it is the first pulse crop mentioned in the Bible. The oldest archaeological remains of lentil are from Greece, dated 11,000 BC, and Syria, dated BC. However, it is uncertain whether they were from cultivated plants or from wild ones. It is from the 5 th millennium BC that unequivocally domesticated lentil seeds have been found. Lentil has been introduced into the Americas, New Zealand and Australia. It is now widely cultivated in temperate and subtropical regions, and in the tropics at higher elevations and in cool seasons. In tropical Africa it is grown in Sudan, Eritrea, Ethiopia (mainly in the northern, central and eastern Highlands), Kenya, Tanzania, Malawi, Zimbabwe, Madagascar, Réunion and Mauritius. It is also cultivated in Morocco, Tunisia, Algeria, Libya, Egypt and South Africa. Uses Lentil is primarily grown for its mature seeds, which are consumed mainly in sauces and soups. In Ethiopia they are used in 'kik wot' (sauce of split seeds), soup (from whole seeds or flour), 'nufro' (boiled and salted), 'azifa' (cooked and mashed) and 'elbet' (paste from flour). Many other dishes are prepared from lentil in different countries. Some of these are: spicy lentil salad, lentil burgers with coriander-yoghurt sauce, lentil and mushroom cottage pie and lentil potatoes. In India split seeds (dhal) are used in soups and the whole seed is eaten salted and fried. The seeds are ground into flour used for cakes and bread and for the preparation of special foods, e.g. for infants and invalids. Young pods, sprouted seeds and leaves are eaten as vegetable. Lentil seeds are occasionally fed to animals as

90 92 CEREALSAND PULSES a source of protein, particularly to poultry. They are sometimes used as a source of starch for the textile and printing industries. The husks, bran and fresh or dried leafy stems provide fodder for livestock. Lentil is sometimes grown for forage or as green manure, though the dry matter production is low. Lentil straw is used as fuel. The seeds are believed to remedy constipation and other intestinal problems. In India they are applied as a poultice to slow-healing sores. In Ethiopia the seeds are credited with aphrodisiac properties. Production and international trade According to FAO statistics, the annual world lentil production in amounted to 3.1 million t/year from 3.8 million ha. The main producers were India (948,000 t/year from 1.43 million ha), Canada (616,000 t/year from 554,000 ha) and Turkey (473,000 t/year from 490,000 ha). In tropical Africa the main producer is Ethiopia (47,000 t/year from 78,000 ha). About 60% of the lentil production in Africa (including North Africa) comes from Ethiopia, where the area under lentil has decreased since the mid-1980s, but in the late 1990s this trend reversed due to the release of cultivars with resistance to rust and fusarium wilt. In Malawi lentil is grown in the northern part (near Mzimba) to supply the Indian community. World lentil exports in amounted to about 1 million t/year. The main exporters were Canada (430,000 t/year), Turkey (127,000 t/year), Australia (124,000 t/year) and India (120,000 t/year). The main importers were Egypt (90,000 t/year), Sri Lanka (86,000 t/year) and Turkey (81,000 t/year). Properties The composition of mature raw lentil seeds per 100 g edible portion is: water 11.2 g, energy 1413 kj (338 kcal), protein 28.1 g, fat 1.0 g, carbohydrate 57.1 g, dietary fibre 30.5 g, Ca 51 mg, Mg 107 mg, P 454 mg, Fe 9.0 mg, Zn 3.6 mg, vitamin A 39 IU, thiamin 0.48 mg, riboflavin 0.25 mg, niacin 2.6 mg, vitamin B mg, folate 433 (ig and ascorbic acid 6.2 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 251 mg, lysine 1957 mg, methionine 238 mg, phenylalanine 1383 mg, threonine 1006 mg, valine 1392 mg, leucine 2034 mg and isoleucine 1212 mg (USDA, 2004). The main limiting amino acids are methionine and cystine. Antinutritional factors include trypsin inhibitors, haemagglutinins, tannins, phytate and oligosaccharides, but the levels are considerably lower than those in e.g. pea and faba bean, and lentils are considered more easily digested. Lentil hay contains moisture 10.2%, protein 4.4%, fat 1.8%, carbohydrate 50.0%, fibre 21.4% and ash 12.2%. Description Erect, pale green annual herb up to 60(-75) cm tall; stem square, muchbranched; taproot slender. Leaves alternate, pinnately compound, with 5-16 leaflets; rachis (1-) (-5) cm long, usually ending in a tendril or bristle; stipules entire, mm long; leaflets opposite or alternate, sessile, oblong or elliptical, (3-)10-15(-20) mm x (1.5-)2-5(-8) mm, entire. Inflorescence an axillary raceme, l-4(-7)-flowered; peduncle slender, (2-) 3 4(-5.5) cm long. Flowers bisexual, papilionaceous; pedicel short; calyx campanulate, narrowly 5-lobed, tube c. 1.5 mm long, lobes c. 3 mm long; corolla pale blue, white or pink, standard 5-7 mm x 4-5 mm, wings c. 4.5 mm x 1.5 mm, keel c. 4.5 mm x 2 mm; stamens 10, 9 united and 1 free, anthers uniform; ovary superior, 1-celled, style inflexed, inner surface bearded. Fruit a rhomboid, laterally compressed pod, 6-20 mm x mm, shortbeaked, l-2(-3)-seeded. Seeds lens-shaped, 2-9 mm x 2-3 mm, grey, green, brownish green, pale red speckled with black, or black; hilum Lens culinaris - 1, flowering and branch; 2, seeds. Source: PROSEA fruiting

91 LENS 93 minute. Seedling with hypogeal germination. Other botanical information In a recent revision of Lens 4 species are recognized on the basis of morphological characters, crossability relationships and cytogenetic, biochemical and molecular evidence; these are Lens culinaris (containing wild and cultivated types) and 3 wild species: Lens ervoides (Brign.) Grande, Lens nigricans (M.Bieb.) Godr. and Lens lamottei Czefr. Lens ervoides is found in East Africa (Ethiopia and Uganda). Lens culinaris has been divided into 4 subspecies (1 cultivated and 3 wild): - subsp. culinaris: stipules entire, lanceolate, pod indéhiscent, glabrous, seed coat spotted; the cultivated lentil; - subsp. odemensis (Ladiz.) M.E.Ferguson et al. (synonym: Lens odemensis Ladiz.): stipules slightly hastate, at least the lower ones slightly toothed, pod dehiscent, glabrous, seed coat with W-shaped pattern; native to Libya, Israel, Turkey and Greece; - subsp. orientalis (Boiss.) Ponert (synonym: Lens orientalis (Boiss.) Hand.-Mazz.): stipules entire, obliquely lanceolate, pod dehiscent, glabrous, seed coat usually spotted; the wild progenitor of the cultivated lentil, distributed from Greece to Uzbekistan and from the Crimean Peninsula to Jordan; - subsp. tomentosus (Ladiz.) M.E.Ferguson et al. (synonym: Lens tomentosus Ladiz.): stipules entire, obliquely lanceolate, pod dehiscent, tomentose, seed coat spotted; native to Syria and Turkey. Lentil cultivars have been divided into 2 cultivar groups, based mainly on seed size: - Microsperma Group: flowers small (5-7 mm long), violet-blue to white or pink, pods small, convex, seeds small (diameter less than 6 mm, 1000-seed weight less than 45 g), convex, cotyledons red, orange or yellow; - Macrosperma Group: flowers large (7-8 mm long), white, rarely blue, pods large, generally flat, seeds large (diameter more than 6 mm, 1000-seed weight more than 45 g), flattened, cotyledons generally yellow, sometimes orange. Macrosperma Group predominates in North Africa, Europe and America, Microsperma Group in Asia, Egypt and Ethiopia. In western Asia and south-eastern Europe both cultivar groups are grown. Growth and development At optimum temperatures lentil seeds germinate in 5-6 days. Flowering starts 6 7 weeks after sowing. Lentil is usually self-fertilized, but up to 1% cross-pollination by insects may occur. The growth cycle ranges from days for early-maturing cultivars to days for late-maturing ones. Lentil is effectively nodulated by Rhizobium leguminosarum. Ecology Lentil is grown as a summer annual in temperate regions and as a winter annual in subtropical regions. In the tropics it is cultivated at higher elevations ( (- 2700) m in Ethiopia) or as a cool season crop. It grows at mean temperatures of 6-27 C, but lentil is not suited to the hot and humid tropics. Intense or prolonged frost and temperatures much higher than 27 C seriously affect growth. Lentil requires an annual rainfall of about 750 mm, with dry conditions around harvest time, but an annual rainfall of mm is tolerated. It is moderately tolerant to drought, but differences exist between cultivars. Lentil normally requires long daylengths for flowering, but the response varies among genotypes, and some cultivars are daylength insensitive. In Ethiopia lentil is grown in the short rainy season ('belg', February-May) and during the main rainy season ('kiremt', June- December), the latter being predominant. To avoid waterlogging the 'kiremt' crop is sown on Vertisols at the end of the rainy season (September) and grown on residual soil moisture. In India lentil is grown during winter on residual soil moisture. Lentil can be grown on a wide range of soil types, from sandy to fairly heavy clay soils, but does not tolerate flooded or waterlogged soils. A ph near 7.0 is best for lentil production, but it tolerates a ph of Lentil is generally very sensitive to salinity. Propagation and planting Lentil is propagated by seed. The 1000-seed weight ranges from g. Seeds remain viable for more than 5 years under cool and dry storage conditions. A dormancy period of 4 6 weeks is common, and some cultivars have been found to be responsive to vernalization. The minimum temperature for germination is 15 C and the optimum temperature C; temperatures above 27 C are harmful. A firm, smooth seedbed is best for lentil. The seed is broadcast, or planted in rows cm apart with 5-25 cm between plants within the row. Seed rates range from only 10 kg/ha in intercropping systems to 150 kg/ha for sole-cropped large-seeded cultivars. The sowing depth is 1-6 cm depending on seed size and moisture availability. Lentil is mainly grown as a sole crop, but sometimes mixed with other crops, e.g. in India with

92 94 CEREALS AND PULSES barley, mustard or castor. Management Lentil is a poor competitor with weeds, especially when young. It should be sown in a clean field and weeding should generally be done within 3 weeks after sowing. Lentil normally responds well to P fertilizer. Effectively nodulated lentil seldom responds to application of N fertilizer. A lentil crop yielding about 2 t seed per ha takes up about 100 kg N, 12 kg P and 65 kg K per ha. In Sudan lentil is grown under irrigation, but elsewhere in tropical Africa it is a rainfed crop. In Ethiopia it is often grown in rotation with the major smallgrain cereals. In crop rotations planting lentil after other legumes, Brassica crops, sunflower or potato should be avoided because these are susceptible to the same diseases. Diseases and pests The economically most important diseases of lentil are rust (Uromyces viciae-fabae), Ascochyta blight (Ascochyta fabae f.sp. lentis), grey mould (Botrytis cinerea), Stemphylium blight (Stemphylium botryosum), collar rot (Sclerotium rolfsii) and fusarium wilt (Fusarium oxysporum f.sp. lentis). Other fungal diseases include Rhizoctonia root rot (Rhizoctonia solani), powdery mildew (Erysiphe polygoni, Leveillula taurica), anthracnose (Colletotrichum spp.), leaf spot (Alternaria alternata) and Sclerotinia stem and root rot (Sclerotinia sclerotiorum). Rust, fusarium wilt and root rot are the most important diseases in Sudan, Eritrea and Ethiopia. Yield losses of 10% due to rust and 50% due to fusarium wilt and root rot have been recorded on Vertisol-grown lentil in Ethiopia. Symptoms of rust are leaves and stems losing their green colour and turning purple, in case of serious infection leading to death of the plant. The spread of rust is favoured by high humidity and moderate temperatures (17-25 C). Control measures include destruction of diseased plants, treatment of seed with fungicide, and the use of resistant cultivars. Fusarium wilt causes leaf curling, followed by wilting of individual branches or the whole plant. It is favoured by light, dry soils. Suggested control measures are crop rotation, treatment of seed with fungicide, and the use of resistant cultivars. Integrated disease management packages have been developed to control wilt and root rot in Ethiopia and Sudan. Seed treatment compounds should be selected and used with care as they can interfere with the nodulation process. Several virus diseases affect lentil, the most important being cucumber mosaic virus (CMV), faba bean necrotic yellows virus (FBNYV), alfalfa mosaic virus (AMV) and tomato spotted wilt virus (TSWV). Pea seed-borne mosaic virus (PSbMV) is common in Ethiopia. Among the common insect pests of lentil, aphids are important. The pea aphid (Acrythosiphon pisum) is the most important aphid in Ethiopia, causing up to 25% yield loss. Stored seeds are attractive to bruchids (Callosobruchus spp.). Broomrape (Orobanche spp.) is an important parasitic weed on lentil in the Mediterranean region and western Asia; it is difficult to control by management practices or genetic means. Harvesting Lentil is harvested when the pods turn yellow-brown and the lower ones are still firm. Further delay may lead to shattering. In many areas the plant is cut down manually to ground level and left to dry for about 10 days, before being threshed and winnowed. Alternatively, for instance in Ethiopia, lentils are harvested by hand-pulling the plants, after which they are left in the field to dry to a seed moisture content of 12-13%. In the United States lentil is harvested mechanically, preferably at a moisture level of 18-20% to prevent excessive shattering and seed damage. Yield The average lentil seed yield in Ethiopia is about 600 kg/ha, which is below the average world yield of about 800 kg/ha. In the Ethiopian highlands, where the growing period is long, yields of about 4 t/ha have been obtained in experiments, and more than 2 t/ha in farmer's fields when the recommended agronomic package was applied. In Asia average seed yields are kg/ha in mixed crops and kg/ha for sole crops. Leafy stem yields of up to 7 t/ha are possible for late-type lentils in Ethiopia. Handling after harvest Harvested lentil should be dried to a moisture content of11 14%; at a lower moisture content seeds tend to break. In Ethiopia the dried plants are spread on a cemented area, where they are threshed by animals, after which the seeds are separated from the residues by winnowing. The clean seeds are stored as whole seeds or in dehulled form. Because of storage insects, mainly Callosobruchus spp., lentil seeds are not stored for more than half a year, except where pit (underground) storage is used. Mechanically harvested lentil seeds can be dried in heated air dryers, but the temperature should not exceed 43 C to reduce cracking of the seed coat. Genetic resources The largest lentil germplasm collection is that of ICARDA (Interna-

93 LENS 95 tional Centre for Agricultural Research in Dry Areas, Aleppo, Syria), with about 10,000 accessions, including wild Lens. Large collections are also kept at the Australian Temperate Field Crops Collection (Horsham, Victoria, Australia, about 4800 accessions), the USDA- ARS Western Regional Plant Introduction Station (Pullman, Washington, United States, about 2800 accessions), and the N.I. Vavilov Ail-Russian Scientific Research Institute of Plant Industry (St. Petersburg, Russia, about 2400 accessions). The largest lentil germplasm collection in tropical Africa (about 370 accessions) is held by the Institute of Biodiversity Conservation (IBC), Addis Ababa, Ethiopia, a country which is considered as a secondary centre of diversity for lentil. Some accessions of Lens ervoides have been collected by IBC. Cultivated lentil shows a wide range of morphological variation, in vegetative as well as in generative parts. Analyses using biochemical and molecular markers such as RFLPs and RAPDs generally show little genetic variation, but more variation is revealed when ISSR markers are used. Breeding Like in many other self-pollinating crops, the genetic variation in lentil has been structured into true-breeding landraces endemic to restricted areas. Since the 1920s breeding work has focused on the collection and evaluation of landraces, on the basis of yield, seed size and disease resistance. Selection is now complemented by crossing programmes, the main breeding objective being yield, but also with attention to broad adaptation, tolerance to environmental stresses, resistance to diseases and pests, and nutritional quality. Considerable progress has been achieved in breeding for resistance to rust, wilt, Ascochyta blight and Stemphylium blight. ICARDA has the global mandate for research on lentil improvement. National lentil improvement programmes in lentil-producing countries use their own germplasm collections and introductions from other institutes for their breeding programmes. The national programmes of lentil-producing countries have released many cultivars. Ethiopia, for instance, has released 10 cultivars ('EL-142', 'R-186', 'Chalew', 'Chekol', 'Adaa', 'Gudo', 'Alemaya', 'Assano', 'Alem Tena' and 'Teshale') and others are being developed for different agroecological zones. Cultivars derived from hybridization schemes are also being developed. Sudan has released some cultivars for its irrigated agriculture. Wild relatives are considered potentially valuable to improve the tolerance to environmental stresses. Different institutions are studying crossability of these wild relatives among themselves and with cultivated lentil. Crosses between Lens culinaris and Lens ervoides or Lens nigricans usually abort, but Fi hybrids can be rescued and produce viable and largely fertile Fa segregates. Successful tissue culture of lentil has been achieved with shoot apical meristem tips, nodal segments and intact seedlings. Genetic transformation of lentil plants has been achieved by electroporation, particle bombardment and Agrobacterium-mediated methods. Fertile transgenic plants have been obtained using particle bombardment. Genetic linkage maps for lentil have been developed. Prospects Lentil seeds are tasty, relatively easily cooked and have excellent nutritional qualities because of the high protein content and good digestibility. The susceptibility of lentil to diseases, especially rust and wilt, has limited its development, but considerable progress has been achieved in breeding for resistance to major diseases. In North and East Africa the demand for lentil remains high while the area and production remained constant or declined until the late 1990s, but recovered thereafter. Currently, there is also an increasing export demand, which can be met with research and development efforts towards increasing yield, setting up seed supply schemes and improving quality through processing industries. The crop can be grown in various agro-ecological zones and is useful in rotations with cereals. Therefore, its role in crop production systems remains important, especially in Ethiopia. Major references Bayaa & Erskine, 1998; Ferguson et al., 2000; Jansen, 1989b; Kay, 1979; Knight (Editor), 2000; Muehlbauer, Cubero & Summerfield, 1985; Muehlbauer & Kaiser (Editors), 1994; Telaye et al. (Editors), 1994; Webb & Hawtin, 1981; Zohary, Other references Abraham & Makkouk, 2002; Bejiga, Tsegaye & Tullu, 1995; Bejiga et al., 1996; Durân et al, 2004; Erskine, 1997; Gulati, Schryer & McHughen, 2002; Hawtin & Chancellor (Editors), 1979; ICARDA, 2002; Lock, 1989; Polhill, 1990; Popelka, Terryn & Higgins, 2004; Rubeena, Ford & Taylor, 2003; Smartt, 1976; Sonnante & Pignone, 2001; Summerfield (Editor), 1988; Tadesse et al., 1999; Thulin, 1983; USDA, 2004; Westphal, 1974; Williams et al, 1994.

94 96 CEREALSAND PULSES Sources of illustration Jansen, 1989b. Authors G. Bejiga LlMEUM OBOVATUM Vicary Protologue Journ. As. Soc. Beng. 16: 1163 (1847). Family Molluginaceae Chromosome number n = 9 Synonyms Limeum indicum Stocks ex T.Anderson (1861). Origin and geographic distribution Limeum obovatum is distributed in the desert regions of Mauritania, Mali, Niger, Chad, Sudan and Eritrea and through northern Africa and Arabia to Pakistan. Uses In Tibesti (northern Chad) the seeds of Limeum obovatum are collected as food. They are a famine food for the Touareg in the Hoggar Mountains in southern Algeria. In Kordofan (Sudan) the plant in all growth stages is reportedly grazed by livestock, especially sheep. In Chad the plant is used for the treatment of burns. Botany Annual or short-lived perennial, glandular-pubescent herb; stems prostrate, up to 40 cm long, pale brown, strongly branched. Leaves opposite, simple and entire; stipules absent; petiole up to 5 mm long; blade orbicular to obovate or elliptical, up to 12 mm x 10 mm, cuneate at base, rounded at apex. Inflorescence an apparently axillary cyme up to 5 mm across. Flowers bisexual, regular, small, green; sepals 5, ovate, c. 2.5 mm long, acuminate; petals absent; stamens 7, inserted on a disk; ovary superior, 2-celled, styles 2. Fruit splitting into 2 mericarps; mericarp indéhiscent, hemispherical, smooth, pale brown, 1-seeded. Limeum comprises about 20 species and is distributed in the Old World tropics, with the centre of distribution in south-western Africa. Limeum is sometimes included in the family Aizoaceae and occasionally in Phytolaccaceae. Ecology Limeum obovatum occurs on dry sandy soils, often in dry riverbeds. In Eritrea it is found in sandy locations on coastal plains. Genetic resources and breeding It is unlikely that Limeum obovatum is threatened by genetic erosion in the light of its wide occurrence and habitat conditions. Prospects Limeum obovatum seems to be a useful wild source of food and fodder in desert regions. However, research on the nutritional and chemical properties of the seeds is needed. Major references Burkill, 1985; Burkill, 2000; Gast, 2000; Gilbert, 2000; Keay, Other references Ozenda, Authors M. Brink LUPINUSALBUS L. Protologue Sp. pi. 2: 721 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 50 Vernacular names White lupin, Egyptian lupin (En). Lupin blanc, lupin (Fr). Tremoceiro, tremoceiro branco, tremoceiro da Beira, tremoço (Po). Origin and geographic distribution White lupin originates from south-eastern Europe and western Asia where wild types still occur. It is known to have been cultivated since ancient times in Greece, Italy, Egypt and Cyprus. The importance of white lupin has fluctuated often during the history of its cultivation; at present it has almost disappeared in central Europe, while it is becoming more widely grown in the Americas. Today it is a traditional minor pulse crop, grown around the Mediterranean and the Black Sea, and in the Nile valley, extending to Sudan and Ethiopia. It is also occasionally grown elsewhere, e.g. in Kenya, Tanzania, Zimbabwe, South Africa, Mauritius, United States and South America (mainly Brazil and Chile). Uses White lupin is traditionally cultivated for human consumption, green manuring and as forage. Before consumption, seeds are first soaked for 1-3 days in running water to remove the bitter, toxic alkaloids, then cooked and eaten as a pulse or pickled in brine and served as a snack. In Ethiopia a high-quality spirit ('araki') is distilled from fermented seeds. In general, consumption of white lupin seeds is restricted to low-income classes and to times of drought, because of their bitter taste. Modern sweet cultivars have very low alkaloid contents, and their seeds do not require laborious detoxification; they are a promising nutritive pulse and can be used as a rich additive for human food and livestock feed products. White lupin plants are fed to livestock as fresh or dry fodder. In southern Europe it is a traditional green manure crop in vineyards and olive plantations. White lupin is a good honey plant and an attractive annual ornamental. In traditional medicine it is used for various ailments, e.g. as an anthelmintic, carminative, deobstruent, diuretic and pectoral. Lupin meal

95 LUPINUS 97 mixed with honey or vinegar is used as a cure for worms, while infusions or poultices are applied to treat boils and skin complaints. Burning seeds are used as an insect repellant. Production and international trade No specific statistics are available for Lupinus albus. About 2 million ha are cultivated with lupin (all species) worldwide, of which 60% is mainly for seed production and 40% for forage and green manure. The major producer of lupin seed is Australia, with about 1.4 million t/year from 1.2 million ha in the early 1990s, mainly Lupinus angustifolius L. for livestock feed. Properties Mature, raw Lupinus albus seeds contain per 100 g edible portion: water 10.4 g, energy 1552 kj (371 kcal), protein 36.2 g, fat 9.7 g, carbohydrate 40.4 g, Ca 176 mg, Mg 198 mg, P 440 mg, Fe 4.4 mg, Zn 4.8 mg, vitamin A 23 IU, thiamin 0.64 mg, riboflavin 0.22 mg, niacin 2.2 mg, vitamin He 0.36 mg, folate 355 ig and ascorbic acid 4.8 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 289 mg, lysine 1933 mg, methionine 255 mg, phenylalanine 1435 mg, threonine 1331 mg, valine 1510 mg, leucine 2743 mg and isoleucine 1615 mg. The principal fatty acids are per 100 g edible portion: oleic acid 3558 mg, linoleic acid 1995 mg, palmitic acid 742 mg, linolenic acid 446 mg, stearic acid 316 mg and eicosenoic acid 255 mg (USDA, 2005). The seed coat makes up about 15% of the seed weight. The net protein utilization for humans is 77% and the protein fraction is low in lysine and methionine. The levels of antinutritional compounds such as condensed tannins and trypsin inhibitors are lower than in other pulses. Suspensions of ground seed of white lupin have shown hypoglycaemic effects in rats. The major alkaloids of white lupin are lupanine, 13-hydroxylupanine and sparteine. The pharmacological effects of these alkaloids are that they block ganglionic transmission, decrease cardiac contractility and contract uterine smooth muscle. 'Sweet lupin' is defined as having less than 200 mg alkaloids/kg; it can be consumed without special precautions. In bitter cultivars the alkaloids, which are watersoluble, can be soaked out from seeds in running water. Processing techniques such as sprouting and fermentation into tempeh also strongly reduce the alkaloid content. Best control is achieved by chemical extraction, which currently is not economically feasible. When white lupin is fed as dried forage, lupinosis can occur. This disease is caused by the ingestion of toxins, known as phomopsins, produced by the fungus Diaporthe toxica that colonizes lupin plants. It is primarily a disease of sheep but can also occur in other livestock and is characterized by severe liver damage, which results in loss of appetite and condition, lethargy, jaundice and often death. Most of the problem can be solved by using Diaportheresistant cultivars such as 'Kiev' and 'Ultra'; where other cultivars are used, overfeeding must be avoided. Botany Annual, erect, branched, bushy, short-hairy herb up to 120 cm tall, with a strong taproot. Leaves alternate, digitately compound with 5-9 leaflets; stipules linear to narrowly triangular, up to 1 cm adnate to the base of the petiole; petiole 3.5 7( 12) cm long; leaflets obovate, 2-6 cm x cm, cuneate at base, rounded and mucronate at apex, nearly glabrous above, hairy beneath. Inflorescence a terminal false raceme 3 30 cm long, manyflowered, lower flowers alternate, upper ones in whorls; peduncle short or absent. Flowers bisexual, papilionaceous; pedicel 1 2 mm long; calyx 8-14 mm long, densely hairy outside, tube c. 4 mm long, 2-lipped, upper lip entire, lower lip entire or slightly 3-toothed; corolla white to violet-blue, standard obovate, mm x 8-12 mm, margins partly reflexed, wings obovate, mm x 6-10 mm, keel ladleshaped, mm x 4 mm, beaked; stamens 10, all joined into a tube; ovary superior, 1- celled, style c. 7.5 mm long with a ring of small hairs below the stigma. Fruit a narrowly oblong, laterally compressed pod 6-15 cm x 1-2 cm, bulging over the seeds, shortly hairy but glabrescent, yellow, 3-6-seeded. Seeds rectangular or square with rounded corners, laterally compressed, 7-16 mm x 6-12 mm x 2-5 mm, more or less smooth, white variably tinged salmon pink or mottled dark brown. Seedling with epigeal germination. Lupinus comprises about 200 species, mostly American; only 12 species are native to the Old World. In tropical Africa 3 native or naturalized species occur and another 9 species have been introduced. Many Lupinus spp. are ornamental garden plants, and 4 species are cultivated on a larger scale as agricultural crops. Lupinus albus represents a crop-weed complex with wide variability in wild and cultivated types. Both types have been classified as subspecies although for the cultivated types a classification into cultivar groups and cultivars would be more appropriate. The wild type is distinguished as subsp. graecus (Boiss. &

96 98 CEREALS AND PULSES Spruner) Franco & P.Silva (synonym: Lupinus graecus Boiss. & Spruner) and can be found in south-eastern Europe and western Asia. The corolla is dark violet-blue, pods are 6 8 cm x1 1.5 cm and shatter seeds at maturity, and seeds are small, 7-10 mm x 6-8 mm x 2-3 mm, mottled dark brown with impermeable seed coat. The cultivated types are distinguished as subsp. albus (synonym: Lupinus termis Forssk.), with corolla white, pods 9-15 cm x cm with non-shattering seeds at maturity, and seeds mm x 8-12 mm x 3-5 mm, pinkish white or white with permeable seed coat. In Ethiopia 2 types of cultivated plants are found: a large-seeded type as grown in Egypt and Sudan, but also a small-seeded type with small leaves. In northern parts of the distribution area of white lupin, in South Africa and in the Americas mostly sweet (lowalkaloid) modern cultivars are grown, whereas in the Mediterranean region and eastern Africa bitter landraces prevail. White lupin is mainly self-pollinating, but 5 10% outcrossing can occur. White lupin nodulates effectively with Bradyrhizobium bacteria. Atmospheric nitrogen fixation rates up to 400 kg N per ha have been observed in Europe and Australia. Ecology Wild white lupin prefers disturbed sites and poor soils, where there is less competition from other species. White lupin is usually grown at mean monthly temperatures during the growing season of C, the optimum being C C. Higher temperatures and moisture stress hinder flowering and pod setting. White lupin is cold-tolerant, but temperatures of 6 to -8 C are harmful at germination, temperatures of -3 to 5 C at flowering. A rainfall of mm during the growing period is optimal for yield. Lupin species are drought-tolerant due to their deep roots, but are sensitive to moisture deficiency during the reproductive period. White lupin is adapted to well-drained, mildly acid or neutral soils of light to medium texture, with ph Growth is hampered on heavy clay and waterlogged soils, while calcareous or alkaline soils induce chlorosis and reduce growth, frequently precluding cultivation. The accepted maximum soil level of CaC03 is 3-5 g/100 g. Some cultivars of white lupin are more tolerant to soil salinity and heavy soils than most other crops. In Ethiopia white lupin is grown at m altitude, on soils too poor for a good faba bean crop. Management White lupin is propagated by seed. The 1000-seed weight ranges from 70 g in some Kenyan populations to more than 1 kg in modern seed cultivars. Seed can easily be stored for 2 4 years under normal conditions; longer storage is possible at lower temperatures. In areas with mild winters such as the Mediterranean region, seed is sown broadcast or drilled from mid September to late October. The seed rate is kg/ha, the seeding depth cm. In Ethiopia seed is sown in the main rainy season (July-September). White lupin is often grown intercropped with cereals or forage legumes, or in rotation with cereals. Weed control is essential until a closed canopy is formed. White lupin is sensitive to P deficiency, but its roots can make more P available through acidification of the rhizosphere, a property from which also associated crops benefit. Wheat intercropped with white lupin has access to a larger pool of P, Mn and N than sole-cropped wheat. Inoculation of the soil with Bradyrhizobium bacteria is beneficial, giving up to a 5-fold increase in yield and a higher protein content of the seed. A well-known commercially available inoculant strain is the Australian WU425. The major diseases of white lupin are root rot and brown leaf spot caused by Pleiochaeta setosa, anthracnose (Colletotrichum acutatum), resulting in early plant death through stem breakage, and rust (Uromyces lupinicolus). Sources of resistance to anthracnose have been found in Ethiopian landraces, but resistant cultivars are not yet available. Bean Yellow Mosaic Virus (BYMV) is the major virus disease; it is transmitted by aphids and by seed. No sources of resistance have yet been identified. White lupin is immune to Cucumber Mosaic Virus (CMV), a major disease of other Lupinus spp. Major pests are the bean seedling maggot (Delia platura, synonym: Phorbia platura) causing seedlings to wilt and die, beetle and moth larvae (e.g. Agriotes and Agrotis spp. killing seedlings), slugs (attacking leaves), thrips (Frankliniella spp., attacking flower buds and leaves), mirid bugs (attacking young pods) and budworms (e.g. Helicoverpa armigera feeding on pod and seed). In Ethiopia harvesting is in December. Seed yields are kg/ha. Genetic resources and breeding Major germplasm collections of white lupin are available in France (INRA, Station d'amélioration des Plantes Fourragères, Lusignan, 1400 accessions), the United Kingdom (University of

97 MACROTYLOMA 99 Reading, Reading, 1100 accessions), Australia (Western Australian Department of Agriculture, South Perth, 890 accessions) and Spain (Servicio de Investigation y Desarrollo Tecnológico, Guadajira, 690 accessions). In tropical Africa small collections are held in Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 25 accessions) and Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 20 accessions). Major objectives in breeding of white lupin are to produce rapid-growing, alkaloid-free, disease-resistant (particularly against anthracnose), high-yielding, high-ph-tolerant, frosttolerant dwarf cultivars, well adapted to local ecological conditions. It appears that bitter cultivars tolerate cold and disease stress better than sweet ones. The level of cross-pollination may limit the relevance of sweet white lupin cultivars in regions where also bitter weedy or cultivated types are present, because pollen of the latter would reintroduce the bitter character in farm-saved sowing seed. Sweet cultivars, however, are a prerequisite for any further breeding advancement. Commercial cultivars are pure lines bred through pedigree selection. Some well-known cultivars of white lupin are: 'Eldo', 'Kiev', 'Multolupa' and 'Ultra'. From Ethiopia 'Bahar Dar' is known. Prospects White lupin is a promising annual legume crop for human consumption, green manuring and forage. The composition of the seed and especially the high protein content makes white lupin highly suitable for livestock diets as a protein-rich product in intensive farming systems. The low level of antinutritional factors facilitates a direct on-farm use of white lupin in self-sustained systems. Since it often can grow on land unsuitable for other crops (too saline, heavy, acid or poor), the development of cultivars adapted to tropical African conditions is highly recommended. Much can be learned from the excellent results obtained with Lupinus angustifolius in Australia. Major references Cowling, Buirchell & Tapia, 1998; Gladstones, Atkins & Hamblin (Editors), 1998; Huyghe, 1997; van Santen et al. (Editors), 2000; Westphal, Other references al-zaid et al., 1991; Duke, 1981; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Haq, 1993; Hill, 1998; Kay, 1979; López-Bellido & Fuentes, 1997; Thulin, 1989a; UC SAREP, undated; USDA, Authors P.C.M. Jansen MACROTYLOMAGEOCARPUM (Harms) Maréchal & Baudet Protologue Bull. Jard. Bot. Belg. 47(1-2): 50 (1977). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 20, 22 Synonyms Kerstingiella geocarpa Harms (1908). Vernacular names Kersting's groundnut, geocarpa groundnut, ground bean (En). Lentille de terre, fève de Kandale, doï, dohi (Fr). Origin and geographic distribution The origin of Kersting's groundnut is not known, but it may originate from northern Togo or central Benin. Supposedly wild types of Kersting's groundnut are found in Cameroon and the Central African Republic, but these may be considered as representing a separate though related species. Kersting's groundnut is cultivated in the West African savanna zone, from Senegal to Nigeria and Cameroon. It is also grown in Mauritius and Fiji and has been grown in Tanzania. Kersting's groundnut is often said to be grown by elderly people only, e.g. in Ghana, and thus gradually going out of production. Uses Kersting's groundnut is cultivated primarily for its edible seeds. Mature seeds are boiled with salt and eaten with palm oil or groundnut oil, and accompanied with fermented cassava flour, called 'gari', yams or rice. They may also be boiled in soups and served to guests as a sign of honour. Dry seeds are ground into flour used in making cakes and Macrotyloma geocarpum - wild and planted

98 100 CEREALS AND PULSES other dishes. In central Benin, for instance, people eat a fried paste made from the seed alone ('ata') or with fermented maize paste ('akassa'). Sometimes roasted seeds of blackseeded types or fresh unshelled pods are boiled with salt and eaten as snacks. Kersting's groundnut seeds play an important role in traditional customs in West Africa, particularly in Togo, where they are used in funeral ceremonies of the Kabyé and Mauba people. This seems to have contributed largely to the survival of the crop in northern Togo. In many areas consumption is limited to the male members of the family, the headman in particular, and the seeds are a favourite dish of voodoo priests. In the tradition of the Sisala people of northern Ghana boiled seeds are the only food served to surviving children during the funeral of their mothers. The leaves of Kersting's groundnut are sometimes eaten as a vegetable or in soups. In northern Ghana and central Benin the water in which the seeds have been boiled is taken against diarrhoea. Powdered dry seed mixed with water or local beer ('pita') is used as an emetic in case of poisoning. Leaf decoctions act as a vermifuge. The Igbo of Nigeria use the plant in the treatment of dysentery, venereal diseases, fever and diabetes. In arid zones, the vegetative parts serve as fodder after the harvest. Production and international trade Reliable production statistics for Kersting's groundnut are not available because it is of little economic importance and mainly grown for local consumption. Some trade exists between neighbouring countries such as Togo, Benin and Nigeria, but no statistics exist. Because of the low yield and poor storage capability the economic importance of Kersting's groundnut has decreased considerably in recent times. Properties The composition of dried Kersting's groundnut seeds per 100 g edible portion is: water 9.7 g, energy 1457 kj (348 kcal), protein 19.4 g, fat 1.1 g, carbohydrate 66.6 g, fibre 5.5 g, Ca 103 mg, P 392 mg, Fe 15.0 mg, thiamin 0.76 mg, riboflavin 0.19 mg, niacin 2.3 mg and ascorbic acid 0 mg (Leung, Busson & Jardin, 1968). The content of essential amino acids per 100 g food is: tryptophan 155 mg, lysine 1280 mg, methionine 267 mg, phenylalanine 1125 mg, threonine 738 mg, valine 1209 mg, leucine 1485 mg and isoleucine 871 mg (FAO, 1970). Kersting's groundnut seeds contain antinutritional factors, including tannins, haemagglutinins and phytate. Boiling pre-soaked (12 hours at 27 C) seeds for 30 minutes reduces tannin content by 98%, haemagglutinating activity by 100% and phytate level by 70%. Description Annual herb with prostrate rooting stems; stem pubescent or almost glabrous, up to 10 cm long. Leaves alternate, 3- foliolate; stipules triangular-ovate, 2-7 mm long, pubescent; petiole erect, up to 25 cm long; rachis c. 7 mm long; stipels linear-lanceolate, 2-5 mm long; petiolules hirsute, lateral ones 1-2 mm long, terminal one 4-10 mm long; leaflets broadly ovate or obovate, 3-8 cm x cm, glabrous, 3-veined from the base. Flowers in pairs or solitary in leaf axils, bisexual, papilionaceous, almost sessile; bracteoles lanceolate, (1 )3.5 4 mm long; calyx pilose, tube mm long, lobes linearlanceolate, (2-)3.5-4 mm long; corolla white or greenish-white, sometimes tinged with purple, standard 6-10 mm x mm, wings 6-7 mm x 1.5 mm, keel mm x 1 mm; stamens 10, 9 fused and 1 free; ovary superior, shortly stalked but stalk elongating during fruit development, 1-celled, style slender, curved, stigma minute. Fruit an indéhiscent pod cm x cm, on a stalk up to 2 cm long, - " H ' ', Macrotyloma geocarpum - 1, plant habit; 2, fruit; 3, seed. Redrawn and adapted by Iskak Syamsudin

99 MACROTYLOMA 101 (l-)2(-3)-seeded, constricted between the seeds, maturing on or below the soil surface. Seeds oblong or oblong-ovoid, 5-10 mm x 4-7 mm x 3 5 mm, whitish, red, brown or black, sometimes striped, spotted or speckled. Seedling with epigeal germination, with cotyledons falling off about 2-3 days after emergence and 2 3 simple lanceolate primary leaves persisting until maturity. Other botanical information Macrotyloma comprises about 25 species, most of which are restricted to Africa. In Macrotyloma geocarpum 2 varieties have been distinguished: var. geocarpum: internodes short, petiole 8-25 cm long, terminal leaflet up to 7.5 cm x 5 cm, pod (l-)2(-3)-seeded, seed c. 9 mm x 6 mm; only known from cultivation; - var. tisserantii (Pellegr.) Maréchal & Baudet: internodes long, petiole up to 1 cm long, terminal leaflet up to 3.5 cm x 2.5 cm, pod l(-2)-seeded, seed c. 5 mm x 4 mm; found wild in Cameroon and the Central African Republic, and perhaps better considered a separate species (originally described as Kerstingiella tisserantii Pellegr.), which is supported by the results of isozyme analysis and possibly also chromosome number. Genotypes are distinguished on the basis of seed colour. White types are best known and used as food, whereas black types mainly serve as medicine or in cultural ceremonies, although they are also used as food. Growth and development Germination of Kersting's groundnut normally occurs within 3 5 days after sowing. The seedling emerges with simple, opposite primary leaves; the first 3-foliolate leaves appear after 5-10 days. Flowering starts days after sowing and may continue until the plant dies. Self pollination is the rule and 2 days after fertilization a stalk is formed at the base of the ovary, carrying the ovary to the ground. This mechanism is similar to that in groundnut, but different from that in bambara groundnut, where the peduncle grows to the ground. Pods mature either on the soil surface or 1-2 cm under it. They reach maturity days after flower opening. The duration of the crop cycle is days. Kersting's groundnut effectively nodulates with nitrogen-fixating bacteria of the Bradyrhizobium group. Ecology Kersting's groundnut is found at altitudes up to 1600 m. It requires ample sunshine and an average temperature of C. It is grown successfully in semi-arid regions with an annual rainfall of mm in 4-5 months, but it is also found on the fringes of the humid tropics. Kersting's groundnut tolerates poor, sandy soils, but sandy loams are required for optimum yields. It is often found on slightly acid soils (ph 5). Propagation and planting Kersting's groundnut is propagated by seed. Seeds used for planting are retained from the previous harvest though some farmers may buy them locally. The 1000-seed weight is g. In West Africa Kersting's groundnut is sown from the beginning to the middle of the rainy season. It is grown mostly in small fields or backyards, in pure stands or intercropped with yam, cowpea, cassava or other crops on mounds, beds or ridges. When grown as a sole crop, it is often the first crop in a rotation, planted in rows cm apart and 15cm within the row. Management Cultivation of Kersting's groundnut is traditional and management mainly consists of 2 3 manual weedings. The use of inorganic fertilizers is not common. Diseases and pests In semi-arid regions Kersting's groundnut is not subject to serious attacks from diseases or pests. In more humid regions fungal diseases (rust, mould) may occur. Stored seed is very liable to infestation by weevils (Piezotrachelus spp.) and beetles (Bruchidae). Harvesting Kersting's groundnut is harvested when leaves start to turn yellow and wither. As the crop is harvested in the dry season, farmers generally dig up whole plants using a hoe and leave them in the field to dry for a few days, after which the pods are picked by hand, allowing easy separation of the pods. Often some seeds are left in the ground after harvesting and germinate with the return of the rains, thus enabling Kersting's groundnut to persist in a semi-wild state. Yield Dry seed yields of Kersting's groundnut average 500 kg/ha. Handling after harvest After harvest, the pods of Kersting's groundnut are dried in the sun to a moisture content of about 12% and stored in granaries or anywhere in the house. They are shelled using a pestle and mortar or by beating with sticks. Usually the major part of the production is sold. Seeds are mostly kept in sealed containers. They are mixed with sand, pepper, ash or insecticide to ensure longer storage. Genetic resources Work on the genetic resources of Kersting's groundnut is relatively recent, and only a few small collections are available. Twelve accessions collected in West

100 102 CEREALS AND PULSES and Central Africa are kept in the gene bank of the International Institute of Tropical Agriculture, Ibadan, Nigeria. Other collections are present in Guinea (Bureau des Ressources Phytogénétiques, Conakry, 8 accessions), Ghana (Plant Genetic Resources Centre, Bunso, 8 accessions), Togo (Institut de Recherches Agronomiques Tropicales et des Cultures Vivrières, Lomé, 8 accessions) and Benin (Agricultural Research Centre of South Benin, Niaouli, 6 accessions). Little is known of the genetic diversity of Kersting's groundnut. In a recent survey of allozyme variation no diversity was found within and among domesticated accessions and within and among wild accessions, but the difference between domesticated and wild accessions was much larger than that found in other tropical legume species. Breeding No breeding programmes of Kersting's groundnut are known to exist. Prospects Kersting's groundnut is a traditional crop of West Africa, and it has largely been replaced by more productive and profitable crops, such as groundnut and cowpea. The low yields, small size of the seeds, amount of labour required for harvesting, and the liability to storage pests are the main causes for its decline. Kersting's groundnut has not entirely disappeared due to its role in traditional ceremonies, but the fact that at present it is mainly grown by elderly people indicates that the decline will continue and that the prospects for this crop are bleak. Major references Achigan Dako, Vodouhè & Koukè, 2003; Amuti, 1980; Baudoin & Mergeai, 2001a; Burkill, 1995; Kay, 1979; Maréchal & Baudet, 1977; Mergeai, 1993; Pasquet, Mergeai & Baudoin, 2002; Rehm, 1989; Verdcourt, Other references Berhaut, 1976; Busson, 1965; Dakora & Muofhe, 1997; Duke, 1981; FAO, 1970; Gillett et al., 1971; Goli, 1997; Hepper, 1958; Hepper, 1963; ILDIS, 2002; IPGRI, undated; Irvine, 1969; Leakey & Wills, 1977; Leung, Busson & Jardin, 1968; Obasi, 1997; Purseglove, 1968; Rehm & Espig, 1991; Schuster et al., 1998; Smartt, 1976; Tamini, 1995; Verdcourt, Sources of illustration Verdcourt, Authors E.G. Achigan Dako & S.R. Vodouhè MACROTYLOMA UNIFLORUM (Lam.) Verde. Protologue Kew Bull. 24: 322 (1970). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 20, 22, 24 Synonyms Dolichos uniflorus Lam. (1786), Dolichos biflorus auct. non L. Vernacular names Horse gram, horse grain, Madras gram (En). Kulthi, grain de cheval (Fr). Feijoeiro de lagartixa, favalinha, culita (Po). Origin and geographic distribution Horse gram is native to the Old World Tropics. It was probably domesticated in India, where its cultivation is known since prehistoric times. Nowadays horse gram is cultivated as a lowgrade pulse crop in southern Asia, mainly from India to Myanmar. It is also grown as a forage and green manure in many tropical countries, especially in Australia and South-East Asia. In tropical Africa horse gram is recorded to occur wild or naturalized in Central, East and Southern Africa. It has also been cultivated as a food crop and green manure in various tropical African countries, but it is unclear to what extent it is currently grown. Uses Mature whole or ground seeds of horse gram are eaten poached, boiled or fried. Sprouted seeds are widely consumed in India. In Myanmar the seeds are boiled, pounded with salt and fermented into a product similar to soya bean sauce. Horse gram seeds are also fed to horses and cattle, usually after boiling. The stems, leaves and pod walls are used as fodder. Horse gram is sown as a green manure or cover crop. In Indian traditional medicine horse gram seeds are used as a diuretic, astringent and tonic. Properties The composition of whole horse gram seeds per 100 g edible portion is: water 9.7 g, energy 1394 kj (333 kcal), protein 22.5 g, fat 1.0 g, carbohydrate 60.5 g and fibre 4.7 g (Leung, Busson & Jardin, 1968). The seeds contain antinutritional compounds such as lectins, trypsin inhibitors, phytates, tannins and oxalic acid. Horse gram seeds have shown in-vivo antihepatotoxic activity in rats. Lipid from the seeds has shown in-vivo protective and healing activity against peptic ulcers in experiments with rats. Extracts from the seeds have shown in-vitro antilithic activity. Botany Climbing herb with stems up to 60 cm tall, with a perennial fibrous rhizome; stem annual, sparsely to densely covered with spreading or appressed whitish hairs. Leaves

101 MACROTYLOMA 103 Macrotyloma uniflorum - 1, part of branch with inflorescence and young fruit; 2, fruits; 3, seeds. Source: PROSEA alternate, 3-foliolate; stipules lanceolate, 4 10 mm long, striate; petiole 1 7 cm long, rachis mm long; petiolules 1-2 mm long; leaflets ovate-rhombic, obovate or elliptical, 1 7( 8) cm x i_4(_8) Cni ; apex rounded to acute, base rounded, lateral leaflets asymmetric, hairy to glabrescent on both surfaces. Inflorescence an axillary (l-)2-3(-5)-flowered fascicle; bracts up to 3 mm long. Flowers bisexual, papilionaceous; pedicel 1 7 mm long; calyx pubescent, tube 2 mm long, lobes triangularlanceolate, 3 8 mm long, long-acuminate, upper pair entirely fused; corolla with cream, yellow or greenish yellow standard, often with a small purple blotch inside, obovate-oblong,6 12 mm x 4-7 mm, wings and keel greenish yellow, 5-10 mm long; stamens 10, 9 fused and 1 free; ovary superior, stiped, 1-celled. Fruit a linear-oblong pod 3 8 cm x 4-8 mm, upcurved towards apex, acuminate, densely hairy when young, later more sparsely so, margins glabrous, smooth or warty, dehiscent, seeded. Seeds trapezoidal, oblong or roundedreniform, 3 8 mm x 3-5 mm, pale to dark reddish brown, speckled or mottled with black and orange-brown or all black. Macrotyloma comprises about 25 species, most of which are restricted to Africa. Within Macrotyloma uniflorum 4 varieties have been distinguished: - var. uniflorum: pods 6 8 mm wide; wild in southern Asia and Namibia, widely cultivated in the tropics as a cover and forage crop; - var. stenocarpum (Brenan) Verde: pods mm wide, shortly stiped and with more or less smooth margins, leaflets pubescent; occurring in Central, East and southern Africa and in India, up to 1700 m altitude in grassland, bushland and thicket, often on sandy soils and in disturbed locations; cultivated in Australia and California (United States); - var. verrucosum Verde: pods mm wide, distinctly stiped and with obscurely to markedly warted margins, leaflets pubescent; occurring in East and southern Africa up to 550 m altitude in grassland and thicket; - var. benadirianum (Chiov.) Verde: pods mm wide, shortly stiped and with slightly warted margins, leaflets densely velvety; occurring in East Africa (Somalia, Kenya) at sea-level on sand dunes and thin soils on coral rag. Horse gram is self-pollinating. Total crop duration is usually 4-6 months. It effectively nodulates with nitrogen-fixing bacteria of the Bradyrhizobium group. Ecology Horse gram requires an average temperature of C and does not tolerate frost. It is drought-resistant and can be grown with rainfall as low as 380 mm. It is mostly grown in areas with less than 900 mm annual rainfall. In higher rainfall areas it is grown on residual moisture in the dry season, e.g. after a rice crop. Most horse gram cultivars are shortday plants. Horse gram grows on a wide range of soils with ph 5-7.5, including poor soils. It does not tolerate waterlogging. Management Horse gram is propagated by seed. The 1000-seed weight is g. The crop is sown broadcast or in rows cm apart, at a seed rate of kg/ha. The sowing depth is cm. In India horse gram is usually sown as a sole crop, but sometimes it is intercropped, e.g. with finger millet, maize, chickpea, groundnut or castor. The main diseases on horse gram in India are horse gram yellow mosaic virus (HgYMV), anthracnose (Colletotrichum lindemuthianum), leaf spot (Cercospora dolichi, synonym: Mycosphaerella cruenta), rust (Uromyces appendiculatum), root

102 104 CEREALS AND PULSES rot {Pellicularia filamentosa, synonym: Thanatephorus cucumeris) and dry root rot (Macrophomina phaseolina). Recorded pests include the gram caterpillar (Azazia rubricans, synonym: Anticarsia irrorata) and the green podboring caterpillar (Etiella zinckenella). Horse gram grown for the seeds is harvested when the pods begin to shrivel and the leaves begin to dry and fall off. The plants are cut or uprooted, stacked, and dried in the sun for a week, after which they are threshed using sticks, stone rollers or oxen. Seed yields are usually low ( kg/ha in India) but much higher yields have been obtained with improved cultivars (900 kg/ha in India, kg/ha in Australia). In experiments in Nigeria in the 1990s seed yields of kg/ha were obtained. When grown for fodder, horse gram can be harvested about 6 weeks after sowing. Forage yields are 4-15 t dry matter per ha. Genetic resources and breeding Germplasm collections of horse gram are held in Australia (Australian Tropical Crops & Forages Genetic Resources Centre, Biloela, Queensland, 38 accessions) and Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 21 accessions). Cultivated horse gram is usually a mixture of several landraces with different seed colours and periods of maturity. Breeding activities are focused on yield potential, resistance to diseases and insensitivity to daylength. Improved cultivars have been developed and released in India; a popular forage and fodder-grain cultivar with indéhiscent pods in Australia is 'Leichhardt'. In-vitro regeneration has been achieved by direct organogenesis using shoot tip and cotyledonary node expiants, and by somatic embryogenesis through cell suspension culture of callus induced on leaf expiants. Prospects It is unclear to what extent horse gram is presently grown in tropical Africa, and how frequently it is consumed as a pulse or used for other purposes. It seems an interesting crop for dry areas in tropical Africa, but more information is needed on the nutritional characteristics of the seed and on the acceptability of its taste for the African consumer. Major references Gillett et al., 1971; Jansen, 1989c; Kay, 1979; Varisai Mohamed et al., 2004; Verdcourt, Other references Garimella, Jolly & Narayanan, 2001; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; ICRISAT, undated; Jayaraj et al., 2000; Laskar et al., 1998; Leung, Busson & Jardin, 1968; Mackinder et al, 2001; Omokanye, 1996; Purseglove, 1968; Sudha et al, Sources of illustration Jansen, 1989c. Authors M. Brink Based on PROSEA 1: Puises. MUCUNAGIGANTEA (Willd.) DC. Protologue Prodr. 2: 405 (1825). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Synonyms Mucuna quadrialata Baker (1871), Mucuna longipedicellata Hauman (1955). Vernacular names Sea bean, burny bean (En). Liane cadoque, liane caiman, mort aux rats (Fr). Mtera (Sw). Origin and geographic distribution Mucuna gigantea is distributed in tropical Asia, Japan, Australia, Pacific Islands and Africa. In tropical Africa it is found from DR Congo to Kenya, Tanzania and Mozambique, also in Madagascar and other Indian Ocean islands. Uses The seeds of Mucuna gigantea are considered edible in Kenya. In India boiled seeds are sometimes eaten as a pulse, e.g. in the Andaman Islands. Aboriginals in Australia used to heat the seeds on hot stones or sand, remove the peel, and grind them to flour, which was then mixed with water, wrapped in leaves and baked. Root decoctions of Mucuna gigantea are taken to treat gonorrhoea and schistosomiasis. In India the bark is applied externally to treat rheumatic complaints. Powdered seed is used as a purgative in Hawaii. The irritant hairs on the outside of the pods are mentioned as being used in criminal poisoning in Malaysia. In Vietnam they are mixed with food to get rid of rats. Properties Mucuna gigantea seeds contain 1.7-2% L-dopa (levodopa; L-3,4-dihydroxyphenylalanine), an amino acid which stimulates the formation of the neurotransmitter dopamine in the brain. Dopamine lessens tremor experienced in Parkinson's disease. However, opinions differ on the side effects and efficacy in the long run of L-dopa. Because of the presence of toxic compounds in the plant, it seems advisable to eat the seed only after prolonged soaking and boiling. Botany Large liana up to 30(-80) m long; stems initially covered with orange-brown bristle hairs, glabrescent. Leaves alternate, 3-

103 ORYZA 105 foliolate; stipules 3 5 mm x 1 mm, deciduous; petiole 4-15 cm long, rachis cm long; stipels needle-shaped, 2-3 mm long, persistent; petiolules c. 5 mm long; leaflets ovate or elliptical, 4-15 cm x 2-9 cm, the lateral ones oblique, acuminate and markedly apiculate at apex, rounded at base, thinly appressed hairy when young, soon glabrescent. Inflorescence an axillary, pendulous false umbel cm long, with flowers on short lateral branchlets 5-10 mm long; peduncle 4-22(-30) cm long. Flowers bisexual, papilionaceous; pedicel cm long; calyx cup-shaped, mm long, 2-lipped, covered with fine grey hairs and long deciduous orange-brown bristle hairs, tube 7-11 mm long, lobes 2 3 mm long, the upper lip somewhat emarginate; corolla pale creamy-green, white or pale lilac, standard (2-) cm x (1.5-)2-2.5 cm, round, with sparse orange-brown bristle hairs, wings and keel (3-) cm long; stamens 10, 9 united and 1 free; ovary superior, 1-celled, style long, filiform, stigma small and terminal. Fruit a stiped pod, oblong or oblong-elliptical, 7-15 cm x 3-5.5(-6.5) cm x 1-2 cm, each margin with 2 wings, densely covered with orange-brown bristle hairs at first, becoming glabrous at maturity, l-4(-6)-seeded. Seeds cm x 2-3 cm x cm, discoid, dark brown or densely mottled with rust brown or black, smooth, hilum extending around the seed-margin for c. three-quarters of the circumference. Seedling with hypogeal germination; first leaves scale-like or simple. Mucuna belongs to the tribe Phaseoleae and comprises about 100 species distributed pantropically. In tropical Africa about 10 species are present. Several subspecies have been distinguished within Mucuna gigantea, with subsp. quadrialata (Baker) Verde, in Africa. However, Mucuna gigantea is very variable throughout its range and it seems not possible to retain subsp. quadrialata. Initial growth of Mucuna gigantea is rapid: seedlings may attain a height of more than 1 m in 3 weeks. In Madagascar it flowers during the dry season. The flowers are much visited by humming-birds. The seeds are dispersed by sea currents. All green plant parts, including the flowers, become black when bruised or dried. Ecology Mucuna gigantea is essentially a littoral species found around the Indian Ocean, but in tropical Africa it also occurs inland. It is found in coastal scrub, on riverbanks, and near water in woodland and forest edges, up to 1800 m altitude. Management Mucuna gigantea is collected from the wild. The presence of the intensely irritant bristle hairs makes handling difficult. Genetic resources and breeding One accession from Kenya is kept in the National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu. In view of its widespread distribution Mucuna gigantea is not threatened by genetic erosion. Prospects Because of the toxic compounds in the seed necessitating long cooking and the presence of irritant hairs on the pods it is unlikely that Mucuna gigantea will become a more important food crop. Major references Beentje, 1994; Dahal & van Valkenburg, 2003; Dick, 1994; du Puy et al., 2002; Gillett et al., Other references Eilittä et al., 2002; Friedmann, 1994; ILDIS, 2002; Mackinder et al., 2001; Neuwinger, 2000; Polhill, 1990; Rajaram & Janardhanan, 1991; Wilmot-Dear, 1984; Wilmot-Dear, 1991; Wilmot-Dear, Authors M. Brink ORYZA BARTHII A.Chev. Protologue Bull. Mus. natn. Hist, nat., Paris 16: 405 (1911). Family Poaceae (Gramineae) Chromosome number 2n 24 Synonyms Oryza breviligulata A.Chev. & Roehr. (1914), Oryza stapfii Roshev. (1931). Vernacular names Wild rice, self-sown rice, Mandinka rice (En). Riz sauvage annuel, riz de marais, riz sauvage (Fr). Origin and geographic distribution Oryza barthii is distributed in tropical Africa from Mauritania east to Ethiopia and south to Botswana and Zimbabwe. Uses The grains of Oryza barthii are sometimes collected if enough plants are available, and they serve as a famine food. They are sometimes sold in markets. However, Oryza barthii is regarded mostly as a weed. Before flowering the plant provides good grazing for livestock; after flowering the awns may cause injury to the mouth. Properties The grain of Oryza barthii has a good flavour. Botany Annual grass up to 150 cm tall, growing in tufts; stem (culm) erect or geniculately ascending, with roots from the lower nodes, spongy, striate, glabrous. Leaves alternate, simple and entire; leaf sheath striate, smooth; ligule 2 6(-9) mm long, truncate or rounded; blade linear, cm x cm,

104 106 CEREALS AND PULSES with acute apex, intense green, glabrous, smooth on the lower surface, slightly rough on the upper surface. Inflorescence a terminal panicle cm x cm, rather dense, erect or more rarely somewhat nodding, with erect or obliquely ascending branches. Spikelet oblong to narrowly oblong, 7-11 mm long (awn excluded), deciduous, pale green to strawcoloured, 3-flowered but 2 lowest florets reduced to sterile lemmas mm long; glumes reduced to a 2-lobed rim; lemma of fertile floret slightly shorter than spikelet, boatshaped, leathery, hairy, with 2 longitudinal lateral grooves, with pink to purplish stiff awn (4-)8-16(-19) cm long; palea about as long as lemma but much narrower, with the apex drawn out in a short blunt point; lodicules 2; stamens 6; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain). Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sativa L. and Oryza glaberrima Steud. Oryza barthii is classified in ser. Sativae, together with Oryza sativa, Oryza glaberrima and Oryza longistaminata A.Chev. & Roehr. Oryza barthii is predominantly inbreeding, with an outcrossing rate of 5-20%. Ecology Oryza barthii grows in shallow water in ponds and marshes, and as a weed in rice fields, up to 1500 m altitude. It may form pure stands, but is usually found scattered with other aquatic grasses. It may become a noxious weed and may act as a reservoir for important rice diseases and pests. Oryza barthii is a short-day plant. Management Oryza barthii is not normally cultivated, but the grain is collected from the wild. The grain shatters very easily, and the panicles are usually collected before they are mature. If ripe, the panicles are harvested over a basket or calabash to collect falling grain. Genetic resources and breeding Oryza barthii has a relatively narrow genetic variation. It is considered a source of resistance to various diseases affecting Oryza sativa, including bacterial leaf blight (Xanthomonas oryzae pv. oryzae), rice yellow mottle virus (RYMV) and sheath blight (Thanatephorus cucumeris, anamorph: Rhizoctonia solani). Prospects Although Oryza barthii may serve as a famine food during times of shortage, it is probably more often considered a weed of Oryza sativa than a valuable food plant, and there seems to be no reason to justify its promotion. The greatest potential of Oryza barthii is probably as a source of resistance to various diseases affecting Oryza sativa. Major references Burkill, 1994; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Launert, 1971; National Research Council, 1996; Smith & Dilday, Other references Abo, Sy & Alegbejo, 1998 Akromah, 1987; Clayton, 1970; Clayton, 1972 Engels, Hawkes & Worede (Editors), 1991 Gibbs Russell et al., 1990; Kaushal & Ravi, 1998; Lu, 1999; Phillips, 1995; Vaughan & Chang, Authors M. Brink ORYZA GLABERRIMA Steud. Protologue Syn. pi. glumac. 1(1): 3 (1853). Family Poaceae (Gramineae) Chromosome number In - 24 Vernacular names African rice, red rice (En). Riz africain, riz de Casamance (Fr). Origin and geographic distribution Oryza glaberrima was derived from the wild annual Oryza barthii A.Chev. (synonym: Oryza breviligulata A.Chev. & Roehr.). Oryza barthii probably grew abundantly in lakes that existed in what is now the Sahara from BC, and it was harvested as a wild cereal. When the climate became drier, Oryza glaberrima, which had gradually developed from Oryza barthii (probably around 1500 BC or later), was grown as a rainfed homegarden crop in oases. When the population took refuge in the interior delta of the Niger river (around 1500 BC) and became much larger, Oryza glaberrima was transformed into the current floating Oryza glaberrima -planted

105 ORYZA 107 rice crop. African rice is now grown in a zone extending from the delta of the River Senegal in the west to Lake Chad in the east. To the south-east its range is bordered by the river basins of the Benue, Logone and Chari, but it has also been recorded from the islands of Pemba and Zanzibar (Tanzania). The areas of most intensive cultivation of African rice are the floodplains of northern Nigeria, the inland delta of the Niger river in Mali, parts of Sierra Leone and the hills on the Ghana-Togo border. African rice was probably introduced into the New World during the slave trade era, and it is still occasionally cultivated there, e.g. in Brazil, Guyana, El Salvador and Panama. Uses In parts of West Africa the grain of African rice is a staple food, highly appreciated for its taste and culinary qualities. It is also used in traditional and ritual ceremonies, e.g. in the Casamance region of southern Senegal. The finer parts of the bran and broken grains are given as feed to chicken and other livestock. In the Central African Republic the root is eaten raw to treat diarrhoea. Production and international trade In statistics on rice production in West Africa no distinction is made between African rice and Asian rice (Oryza sativa L.). It is estimated that African rice is grown in less than 20% of the total area allocated to rice in West Africa. As a traditional food grain it is not traded internationally, but only within the region of production. Properties The composition of whole African rice grain (hulled) per 100 g edible portion is: water 11.3 g, energy 1524 kj (364 kcal), protein 7.4 g, fat 2.2 g, carbohydrate 77.7 g, fibre 0.4 g, Ca 38 mg, P 294 mg, Fe 2.8 mg, thiamin 0.34 mg and niacin 6.5 mg. Milled African rice contains per 100 g fresh edible portion: water 11.4 g, energy 1532 kj (366 kcal), protein 6.3 g, fat 0.3 g, carbohydrate 81.6 g, fibre 0.2 g, Ca 22 mg, P 98 mg, Fe 1.7 mg, thiamin 0.06 mg, niacin 2.0 mg and tryptophan 110 mg (Leung, Busson & Jardin, 1968). African rice is superior to Asian rice in its content of the important vitamin thiamin and in iron. The degree of gelatinization depends on the amylose content, which ranges from 14-30%, and influences consistency of the rice in cooking and thus consumer choice. Most cultivars of African rice have red-skinned grain and some are strongly scented. Adulterations and substitutes In most regions of West Africa, at least in commercial farming, African rice has been replaced by Asian rice, which is more productive, shatters less easily and has a softer grain that is easier to mill. Small-scale farmers in West Africa, however, often still prefer to grow African rice for its taste and culinary properties, its ability to withstand flooding, and its resistance to several diseases and pests. Description Annual grass up to 120 cm tall (up to 5 m in some floating types), often tufted; dryland types with simple culm often rooting at lower nodes, floating types often branching and rooting at upper nodes too. Leaves alternate, simple; sheath terete, up to 25 cm long, with transverse veinlets; ligule c. 4 mm long, truncate, membranous; blade linear, flat, 20-25(- 30) cm x 6-9 mm, sagittate at base, rugose beneath. Inflorescence a terminal, ellipsoid, stiff and compact panicle up to 25 cm long, with ascendent racemose branches. Spikelets ellipsoid, c. 9 mm x 4 mm, more or less persistent, 3-flowered but 2 lowest florets reduced to sterile lemmas separated from the lemma of the fertile, bisexual upper floret by a stipe; glumes absent or strongly rudimentary; lemma hispidulous, 5-veined, usually without apical awn; palea 3-veined; lodicules 2; stamens 6; ovary superior, with 2 plumose stigmas. Fruit Oryza glaberrima - 1, plant habit; 2, inflorescence; 3, spikelet. Redrawn and adapted by W. Wessel-Brand

106 108 CEREALS AND PULSES a laterally compressed caryopsis (grain) up to 9 mm x 3 mm, often reddish, tightly enveloped by lemma and palea. Other botanical information Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sativa and Oryza glaberrima. Several classifications of Oryza have been made. Most recently the genus has been divided into 3 sections: sect. Pädia, sect. Brachyantha and sect. Oryza. Section Oryza is subdivided into 3 series: ser. Latifoliae, ser. Australiensis and ser. Sativae. Oryza glaberrima, its direct ancestor Oryza barthii A.Chev. and the rhizomatous perennial Oryza longistaminata A.Chev. & Roehr. are classified in ser. Sativae, together with Oryza sativa. Morphologically, Oryza glaberrima can be distinguished from Oryza sativa by its shorter ligule and less-branched panicle. Growth and development African rice seedlings normally emerge in 4 5 days after sowing. The vegetative phase of African rice consists of a juvenile phase of about 3 weeks followed by a tillering phase of 3 4 weeks. Vegetative growth is rapid. Tillering, high leaf area index and high specific leaf area contribute to its high competitiveness against weeds. However, culms tend to be weak and brittle, making African rice prone to lodging. African rice is self-fertilizing. The duration of the crop varies from 3-6 months depending on cultivar and type of culture. Some cultivars selected for rainfed conditions are of very short duration, shorter than cultivars of Oryza sativa. Cultivars for deep water conditions tolerate flooding up to 2.5 m deep and culms may grow up to 5 m long. Some shattering of seed occurs in many cultivars. Ecology African rice grows well above 30 C, but above 35 C spikelet fertility is noticeably reduced. Temperatures below 25 C reduce growth and yield; temperatures below 20 C do so markedly. African rice is grown from sealevel to 1700 m altitude. It is generally a shortday plant, but photosensitivity varies between cultivars from day-neutral to strongly sensitive. African rice is grown on a wide range of soils. Although preferring fertile alluvial soils, it tolerates low soil fertility. Some cultivars can produce higher yields than Asian rice on alkaline and on phosphorus-deficient soils. They are also more tolerant to iron-toxicity. Floating rice is planted on loam or clay soils. Propagation and planting African rice is propagated by seed. The weight of 1000 seeds is g. Seed dormancy disappears a few months after maturity; for experimental purposes, dormancy can be broken by removing the lemma and palea and about one-third of the albumen, allowing germination in 2-3 days. Before sowing the soil may be prepared with a hoe or, as in Senegal, Gambia and Guinea, with a long-handled spade, but soil preparation is rarely practised. Seed is mostly broadcast and transplanting is rarely practised. For floating rice, seed is densely sown in soil that has been recently weeded and that may or may not have been ploughed or hoed. Cultivars are selected according to expected flood duration and generally have a growing period of 4-6 months. In West Africa from Senegal to northern Cameroon, where rainfall generally exceeds 1000 mm/year, African rice is mostly planted as an upland crop, depending solely on rain and surface run-off. In some regions short-duration cultivars are grown that are adapted to annual rainfall amounts as low as 700 mm. In Senegal and Gambia the crop is sown in moist locations, often under palm trees, after simple soil cultivation. This is locally called 'riz de plateau'. 'Riz de montagne' is grown throughout the forest zone covering western Côte d'ivoire, Liberia, the Fouta Djallon and eastern Guinea mountains. It is grown in shifting cultivation, often following logging, even on steep slopes. The undergrowth is cut and at the end of the dry season fields are burned. Sowing is mostly carried out without any soil cultivation. Rice is grown in pure stands or intercropped with other crops, e.g. maize. After 2-3 years, the field is used to grow cash crops such as cacao or coffee, or left fallow. Farmers return after years, or later, depending on the recovery of the vegetation and the soil. In such fields, cultivars of shortest duration are grown and African rice is only rarely replaced by Asian rice, e.g. in the forest zone of Guinea and western Côte d'ivoire. Irrigated rice systems depend more on river water than on rainfall and are found in areas with a much drier climate; the degree of control of irrigation is variable. Floodplain rice on hydromorphic soils is found in Guinea, Côte d'ivoire, Mali, Burkina Faso and Nigeria. Floating rice cultivars are very common in the interior delta of the Niger river in Mali, and is also planted in Senegal, Gambia, Niger and Nigeria. It grows sometimes very rapidly in length as the flood water rises, tolerating sub-

107 ORYZA 109 mersion for several days. Cultivars grown have a crop duration of 4-5 months. Along the rivers in northern Senegal and in Mali, in the northern part of the interior delta of the Niger river south-west of Timbuktu, in a zone stretching from Dire and Goundam to the series of lakes Faguibine, Gouber and Kamango, rice is grown on floodplains after floods have receded. In this cropping system, rice is sown in moist soil and the crop development relies on ground water ('riz de décrue'). Weeds are few. Both Oryza glaberrima and Oryza sativa are grown and have a duration of 4-5 months. Along the Atlantic coast, e.g. in Sierra Leone, African rice is grown in mangrove swamps. Management Weeding of African rice in non-flooded areas is manual and often late. In some regions, such as the Basse Casamance, weed control is combined with land preparation: a first light irrigation favours the germination of weeds, which can subsequently be eradicated. Mechanization and fertilizer application are rarely practised. In floodplain and wet rice cultivation neither crop rotation nor fallow is practised, contrary to the practice for upland rice. Diseases and pests The most important and widespread disease of African rice is rice blast (Pyricularia grisea; synonyms: Magnaporthe grisea, Pyricularia oryzae). Rice yellow mosaic virus (RYMV) and soil parasites (nematodes) often cause large losses. There are few control measures, but some cultivars are resistant to such pathogens. In floodplain and wet rice systems the main problems are rizophagous fish (Distichodus, Tilapia), while birds cause serious damage in all rice cropping systems. Children armed with pebbles and slings offer some protection. Rodents, buffaloes, elephants and hippopotamuses can all cause serious damage. African rice gall midge (Orseolia oryziphora), crickets and grasshoppers are also important pests, as are stem-borers that destroy the apex of the plants and so prevent the formation of inflorescences. Annual wild rice {Oryza barthii) is very common in wet rice fields. It can be recognized by its red awns but it is then too late to remove it. It is characterized by very strong shattering and, as it often ripens before the cultivated rice, it multiplies and spreads throughout the rice field. It is sometimes harvested with the rice crop. If the seed is not cleaned carefully, the field will be infested with wild rice within a few years. Annual wild rice readily crosspollinates with Oryza glaberrima; the resulting red grains shatter more easily and have to be milled more tightly, resulting in more weight loss and higher costs. Under conditions of deep flooding, perennial wild rice (Oryza longistaminata) is cut below the surface of the water in order to kill it. Harvesting The harvesting season for African rice is October-December. Upland rice is harvested first. Panicles are bundled and stacked in elevated granaries under which a smoking fire is maintained to keep away storage insects. After manual or mechanical threshing, grain can also be stored in bulk in bags. Floating rice is harvested in several rounds mostly from canoes, which leads to considerable losses. Yield Yields of African rice obtained under traditional conditions rarely average more than 1 t/ha. In experiments with deep water rice cultivars carried out in Gao and Timbuktu (Mali) from , yields of 1-4 t/ha were obtained. Handling after harvest The produce of African rice, whether stored before or after threshing, should be protected against pests, mainly insects and rodents. The paddy should be dried well to reduce the moisture content to a maximum of 14% to achieve good storage and a high milling yield. The grain of African rice is more brittle than that of Oryza sativa, making it more difficult to mill. Genetic resources IRD (Institut de Recherche pour le Développement, formerly ORSTOM) and CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement) collected cultivated and related wild types of rice (both African and introduced) throughout their area of distribution. Between 1974 and 1983, over 3700 samples were collected in Africa and Madagascar, of which 20% are Oryza glaberrima and 12% related wild species. These collections are kept in cold storage (4 C, 20% humidity) for mediumterm conservation and partly frozen at -20 C for long-term storage at IRD in Montpellier (France). The collection is duplicated at CIRAD in France and at the International Rice Research Institute (IRRI), the Philippines. The International Institute of Tropical Agriculture (UTA), Ibadan, Nigeria keeps almost 2800 accessions, and the Africa Rice Center (WARDA), Bouaké, Côte d'ivoire, almost 1900 accessions. Collections of Oryza glaberrima germplasm are also kept at the Bangladesh Rice Research Institute, Dhaka, Bangladesh (200 accessions)

108 110 CEREALS AND PULSES and the USDA-ARS National Small Grain Collection, Aberdeen, Idaho, United States (174 accessions). African rice shows orthodox seed storage behaviour. Currently no in-situ conservation programmes of rice of African origin exist but they would be desirable. Breeding While the genetic variation in Oryza glaberrima is small in comparison with that of Oryza sativa, types with important characteristics have been identified: resistance to RYMV, rice blast (Pyricularia grisea), African rice hispa (Trichispa sericea), the African rice gall midge (Orseolia oryziphora), and to several stem-borers and nematodes, including Heterodera sacchari, Meloidogyne graminicola and Meloidogyne incognita. African rice shows resistance to salinity, drought and iron toxicity and it competes well with weeds. Various cultivars have shown partial resistance to and tolerance of parasitic plants of the genus Striga. In general, hybrids between Oryza glaberrima and Oryza sativa are highly sterile in the Fi and early generations. However, in a hybridization programme initiated in 1992,WARDA succeeded in crossing the two species into stable and fertile progenies through backcrossing and doubled haploid breeding. Interspecific progenies, which are called 'New Rice for Africa' (NERICA), are now being grown by farmers in Africa. They are more productive than Oryza glaberrima, but retain favourable characteristics such as competitiveness against weeds, resistance to diseases and pests, tolerance to poor soils, and high grain quality. Few genetic improvement programmes of Oryza glaberrima itself have been undertaken. Extensive genetic linkage maps have been made for rice, and IRD andwarda are working together in a programme to systematically integrate the genome of Oryza glaberrrima into that of Oryza sativa. The objective is to follow the introgression of small genome fragments of Oryza glaberrima into the genetic base of Oryza sativa using molecular markers. Prospects For over 30 years it has been predicted that African rice would disappear under the pressure of widespread introduction of improved cultivars of Oryza sativa, but this has not happened, although in Burkina Faso, for example, a strong decline of African rice has been observed. The explanation for the resilience of African rice is that it is highly appreciated by the people of West Africa, who continue to grow African rice for its taste and culinary properties, and that it is highly adapted to particular growing conditions, e.g. as floating rice. Cross-breeding of Oryza glaberrima and Oryza sativa should continue to include programmes aiming at the transfer of genome fragments. Such breeding programmes should be carried out in association with a programme of in-situ conservation of genetic resources of wild and cultivated rice of African origin. For specific objectives certain regions should be identified, e.g. Guinea for its diversity of rice cropping systems, the regions of southern Chad/northern Cameroon and the interior delta of the Niger river in Mali for the contacts between wild and cultivated types, and the valley of the Ferlo in Senegal to study spontaneous populations of the annual Oryza barthii away from all rice cultivation. Improvement of African rice cultivation should aim at decreased lodging, increased yield, less seed scattering and decreased brittleness of the grain. Major references Bezançon, 1994; Brenière, 1983; Jones et al., 1994; Jones et al., 1997; Linares, 2002; Lorieux, Ndjiondjop & Ghesquière, 2000; Lu, 1999; National Research Council, 1996; Séré & Sy, 1997; Sumi & Katayama, Other references Aluko et al., 2004; Bettencourt & Konopka, 1990; Bezançon, 1995; Bouharmont, Olivier & Dumont de Chassart, 1985; Buddenhagen & Persley (Editors), 1978; Burkill, 1994; Catling, 1992; Chang, 1995; Guei, Adam & Traoré, 2002; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Heuer et al, 2003; IPGRI, undated; Johnson et al., 1997; Leung, Busson & Jardin, 1968; Nwilene et al, 2002; Plowright et al, 1999; Purseglove, 1972; Rehm & Espig, 1991; Ukwungwu, Williams & Okhidievbie, 1998; Watanabe et al., Sources of illustration National Research Council, 1996; Roshevitz, Authors G. Bezançon & S. Diallo ORYZA LONGISTAMINATA A.Chev. & Roehr. Protologue Compt. Rend. Acad. Sei., sér. 2, Mec. Phys. Chim. Sei. Univers. Sei. Terre. 159: 561 (1914). Family Poaceae (Gramineae) Chromosome number 2n = 24 Synonyms Oryza barthii auct. non A.Chev. Vernacular names Wild rice, red rice (En). Riz sauvage vivace, riz vivace (Fr). Origin and geographic distribution Oryza longistaminata is distributed throughout tropical Africa (including Madagascar) and is also

109 ORYZA ill found in South Africa. Uses The grains of Oryza longistaminata are sometimes eaten and sold on local markets. They serve as famine food, e.g. in Sudan and Ethiopia. Dense stands provide good grazing for cattle. The straw is used for thatching. Botany Robust perennial grass up to 2.5 m tall, with long, creeping, branched rhizomes; stem (culm) up to 2.5cm or more in diameter, erect or ascending, with aerial roots from the lower nodes, glabrous. Leaves alternate, simple and entire; leaf sheath spongy, pale green to brownish, smooth, glabrous; ligule (l-) cm long, acute, often split down the middle; blade linear, 10-45(-75) cm x (^2.5) cm, acuminate, bright to dark green, glabrous, smooth or slightly rough on the lower surface, slightly rough on the upper surface. Inflorescence a terminal panicle cm x cm, dense, erect or slightly drooping, with obliquely ascending to almost erect branches. Spikelet asymmetrically elliptical-oblong, 7 12(-15) mm long (awn excluded), deciduous, pale green to brownish, 3-flowered but 2 lowest florets reduced to sterile lemmas (2-)2.5-4(-4.5) mm long; glumes reduced to a membranous rim; lemma of fertile floret slightly shorter than spikelet, boat-shaped, leathery, hairy, with pink or purplish, rather slender awn (2.5 )4 7.5( 8) cm long; palea slightly shorter than lemma and much narrower, acute or tapering into a point; lodicules 2; stamens 6; ovary superior, with 2 plumose blackish stigmas. Fruit an oblong caryopsis (grain) mm long, glabrous, pale brown, glossy. Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sauva L. and Oryza glaberrima Steud. Oryza longistaminata is classified in ser. Sativae, together with Oryza sativa, Oryza glaberrima and Oryza barthii A.Chev. Oryza longistaminata can be distinguished from other wild Oryza spp. by its very long, pointed ligule. Oryza longistaminata is partly self-incompatible and allogamous. Often only few seeds are set and natural reproduction is mainly by its rhizomes. Ecology Oryza longistaminata is found in shallow or deep water in pans, pools, swamps, flood plains and riverbanks, up to 1800 m altitude. It often occurs in pure stands. Oryza longistaminata is a noxious weed in wet-rice cultivation; it suppresses cultivated rice and forms hybrids with it. It may also act as a reservoir for important rice diseases and pests, such as bacterial leaf blight (Xanthomonas oryzae pv. oryzae). Management Oryza longistaminata is mostly collected from the wild and only occasionally cultivated. The grains shatter easily, and it is common practice to harvest panicles just before maturity or to shake ripe panicles over a basket or calabash. The long, scabrid awns form a disincentive to touch the panicle. Genetic resources and breeding As seed production of Oryza longistaminata is very poor, in situ conservation is recommended. Oryza longistaminata is considered a sourceof resistance genes to various diseases affecting cultivated Oryza sativa. Resistance to bacterial leaf blight has successfully been transferred. Oryza longistaminata is a host plant of rice yellow mottle virus (RYMV), an important disease of Oryza sativa in Africa, but in general Oryza longistaminata is more tolerant of it, and some accessions are immune. Oryza longistaminata is a potential source of genes for the development of perennial types of Oryza sativa, which would provide a permanent ground cover and reduce erosion. Prospects Oryza longistaminata serves as a famine food during times of shortage, but is also a noxious weed of Oryza sativa. The greatest potential of Oryza longistaminata is probably in Oryza sativa breeding as a source of genes conferring disease resistance and perennial habit. Major references Burkill, 1994; Engels, Hawkes & Worede (Editors), 1991; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Launert, 1971; National Research Council, Other references Abo, Sy & Alegbejo, 1998; Akromah, 1987; Clayton, 1970; Clayton, 1972; Gibbs Russell et al, 1990; Lu, 1999; Phillips, 1995; Sacks, Roxas & Sta Cruz, 2003; Smith & Dilday, 2003; Vaughan & Chang, Authors M. Brink ORYZA PUNCTATA Kotschy ex Steud. Protologue Syn. pi. glumac. 1(1): 3 (1853). Family Poaceae (Gramineae) Chromosome number 2n = 24, 48 Vernacular names Red rice, wadi rice (En). Mchetez (Sw). Origin and geographic distribution Oryza punctata is distributed in tropical Africa from Côte d'ivoire to Sudan and southwards to Angola, Zimbabwe, Mozambique and Madagascar.

110 112 CEREALS AND PULSES It also occurs in South Africa and Thailand. Uses The husked grains of Oryza punctata are sometimes eaten as a famine food in Sudan and Kenya. In Sudan they are consumed after boiling with milk or water. Properties Per 100 g dry matter the grain of Oryza punctata from Sudan contains: crude protein 13.9 g, fat 4.0 g, soluble carbohydrate 74.8 g, crude fibre 2.9 g, Ca 40 mg, Mg 270 mg, P 550 mg, Fe 16.8 mg and Zn 3.9 mg. The essential amino acid composition per 100 g protein (16 g N) is: lysine 3.6 g, methionine 2.2 g, phenylalanine 5.2 g, threonine 3.4 g, valine 5.9 g, leucine 8.6 g and isoleucine 4.1 g (Salih & Nour, 1992). Botany Annual or perennial grass (- 150) cm tall, growing in tufts; stem (culm) erect or geniculately ascending, branched, striate, glabrous. Leaves alternate, simple and entire; leaf sheath often spongy, distinctly striate; ligule 3 10 mm long, rounded, truncate or somewhat acute; blade linear, cm x cm, acuminate, pale green or rarely glaucous, glabrous, usually slightly rough on both surfaces. Inflorescence a terminal panicle cm x 3-17 cm, loose, erect or somewhat drooping, with spreading or ascending branches. Spikelet asymmetrically ellipticaloblong or broadly oblong, (5-) mm long, deciduous, greyish green or glaucous, 3- flowered but 2 lowest florets reduced to sterile lemmas mm long; glumes reduced to a membranous, whitish narrow rim; lemma of fertile floret slightly shorter than spikelet, boat-shaped, leathery, hairy or rarely glabrous, with pale yellow slender flexuous awn (1 )2 7.5 cm long; palea slightly shorter than lemma and much narrower, acute or tapering into a short point; lodicules 2; stamens 6; ovary superior, with 2 plumose blackish stigmas. Fruit an oblong caryopsis (grain) 4-5 mm long, glabrous, pale brown. Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sativa L. and Oryza glaberrima Steud. Oryza punctata is classified in ser. Latifoliae. Within Oryza punctata diploid (2re = 24) and tetraploid (2n = 48) plants are known. Oryza punctata can be crossed with Oryza sativa using embryo rescue techniques. Ecology Oryza punctata is found in swampy locations, on stream banks, in pond margins and pools, up to 1200 m altitude. It is a noxious weed in rice cultivation and a potential seed contaminant of rice cultivars. Management Oryza punctata is collected from the wild. The 1000-seed weight is about 25 g. Husking requires vigorous pounding, resulting in the grain being seldom whole when eaten. Genetic resources and breeding Oryza punctata is considered a source of resistance to various diseases and pests affecting Oryza sativa, including bacterial leaf blight (Xanthomonas oryzae pv. oryzae) and brown planthopper (Nilaparvata lugens). Prospects Although the grains of Oryza punctata have a good nutritional quality, they seem to be used as a famine food only, and the plant is considered a noxious weed in rice cultivation. Oryza punctata may be useful in Oryza sativa breeding, although it is genetically more distant than Oryza barthii A.Chev. and Oryza longistaminata A.Chev. & Roehr. Major references Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Kaushal & Ravi, 1998; Launert, 1971; National Research Council, 1996; Salih & Nour, Other references Burkill, 1994; Clayton, 1970; Clayton, 1972; Gibbs Russell et al., 1990; Lu, 1999; Mahmoud et al., 1995; Smith & Dilday, 2003; Vaughan & Chang, Authors M. Brink ORYZA SATIVA L. Protologue Sp. pi. 1: 333 (1753). Family Poaceae (Gramineae) Chromosome number 2n = 12, 24, 36 Vernacular names Rice, paddy, Asian rice, Asiatic rice (En). Riz, riz asiatique (Fr). Arroz (Po). Mpunga (Sw). Origin and geographic distribution Oryza sativa evolved in Asia, but the exact time and place of its domestication are not known for certain. Remains of rice in China have been dated to 6500 BC; the earliest archaeological evidence from India goes back to 2500 BC. Oryza sativa was brought from Asia into tropical Africa along different routes. Seamenfarmers began sailing from Indonesia to Madagascar probably a few centuries BC and started cultivating Oryza sativa there. Another important contact between Africa and Asia at the dawn of the Christian era was the trade route from Sri Lanka and India via Oman to Somalia and the islands Zanzibar and Kilwa off the coast of Tanzania. Most probably Oryza sativa migrated from Egypt, where it was introduced

111 ORYZA 113 Oryza sativa -planted about AD, to West Africa. The final penetration of Oryza sativa into Africa was along the slave trading routes from the East African coast and Zanzibar to DR Congo from about 1500 AD onwards. At the same time Oryza sativa was introduced into Senegal, Guinea Bissau and Sierra Leone by the Portuguese on their return from expeditions to India. Nowadays it is cultivated throughout the humid tropics and in many subtropical and temperate areas with a frost-free period longer than 130 days. Uses The rice grain is cooked by boiling or steaming, and eaten mostly with pulses, vegetables, fish or meat. Flour from rice is used for breakfast foods, baby foods, bread and cake mixes and cosmetics. Starch made from broken rice is used as laundry starch and in foods, cosmetics and textile manufacture. Beers, wines and spirits are made from rice. The husk or hull is used as fuel, bedding, absorbent, packing material and as carrier for vitamins and drugs; it is also made into building board. The charred hull is used for filtration of impurities in water, a medium for hydroponics and manufacture of charcoal briquettes. Rice bran or meal obtained in pearling and polishing is a valuable livestock and poultry feed. Oil is extracted from the bran. Crude rice bran oil is processed into solidified oil, stearic and oleic acids, glycerine and soap. Processed bran oil is used for cooking, antirust and anticorrosive agents, textile and leather finishers, and in medicine. Rice straw is used for animal feed and bedding, for the manufacture of straw boards and pulp for paper, for the production of compost and mushroom growing medium, for mulching vegetable crops, for making ropes, sacks, mats and hats, for roof thatching, and to make plastering material (mixed with clay mud) for the construction of houses, and for incorporation into the soil or burning on the field as a way to maintain/improve soil fertility. Several traditional medicinal applications of rice have been reported from tropical Africa: leaf dressings are applied to ulcers and grain decoctions are drunk to treat diarrhoea, as a diuretic and as an emollient. Rice powder is applied against itch in Senegal. In DR Congo a decoction of the roots, leaves and husks is taken against madness and beriberi. Production and international trade According to FAO estimates the average annual world production during was 593 million t paddy (unhusked grain) from 153 million ha. Asia accounts for 90% of the world production and area. During tropical Africa produced on average 11.9 million t paddy (2% of world production) annually on 7.7 million ha (5% of world area); these data include African rice (Oryza glaberrima Steud.), which occupies less than 20% of the rice area in West Africa. The main producers are Nigeria (3.5 million t from 2.9 million ha), Madagascar (2.6 million t from 1.2 million ha) and Côte d'ivoire (1.1 million t from 0.5 million ha). The annual world paddy production increased steadily from 241 million t/year in to 593 million t/year in , and the harvested area from 121 to 153 million ha. In the same period the annual paddy production in tropical Africa increased from 3.6 to 11.9 million t/year, and the harvested area from 2.8 to 7.7 million ha. Only 5% of the world's rice production enters into international trade. Thailand is the world's largest exporter of milled rice (26% of world trade during ) followed by Vietnam, India, the United States, China and Pakistan. All countries in tropical Africa are net importers of milled rice and during an average of 4.8 million t milled rice was imported annually. This means that more than one third of the rice consumption in tropical Africa is satisfied through imports. Main rice importers are Nigeria, Senegal and Côte d'ivoire. Per capita annual milled rice consumption in tropical Africa varies tremendously between 0.15 kg and 95 kg with an average of about 18 kg for the period In Madagascar, Sierra Leone and Guinea Bissau it is the main source of energy.

112 114 CEREALS AND PULSES Properties Raw brown rice contains per 100 g edible portion: water 13.9 g, energy 1518 kj (363 kcal), protein 6.7 g, fat 2.8 g, carbohydrate 81.3 g, dietary fibre 3.8 g, Ca 10 mg, Mg 110 mg, P 310 mg, Fe 1.4 mg, Zn 1.8 mg, thiamin 0.59 mg, riboflavin 0.07 mg, niacin 5.3 mg, vitamin B mg, folate 49 ug, ascorbic acid 0 mg. Raw polished rice contains per 100 g edible portion: water 11.7 g, energy 1536 kj (367 kcal), protein 6.5 g, fat 1.0 g, carbohydrate 86.8 g, dietary fibre 2.2 g, Ca 4 mg, Mg 13 mg, P 100 mg, Fe 0.5 mg, Zn 1.3 mg, thiamin 0.08 mg, riboflavin 0.02 mg, niacin 1.5 mg, vitamin B mg, folate 20 (ig, ascorbic acid 0 mg (Holland, Unwin & Buss, 1988). The essential amino acid composition of raw polished rice per 100 g edible portion is: tryptophan 87 mg, lysine 250 mg, methionine 140 mg, phenylalanine 330 mg, threonine 230 mg, valine 390 mg, leucine 560 mg and isoleucine 260 mg (Paul, Southgate & Russell, 1980). Milling and polishing result in a loss of protein, fat, minerals (phosphorus and potassium) and vitamins (thiamin, riboflavin and niacin). However, these operations improve the storability and reduce the cooking time. Rice grain endosperm may be waxy (glutinous) or non-waxy (non-glutinous) depending on the content of amylose and amylopectin. The higher the amylopectin content, the more glutinous the product is. The endosperm also contains sugar, fat, crude fibre, vitamins and inorganic matter. The flavour of rice is variable and aromatic rice cultivars are highly appreciated throughout the world. A major component of the flavour is 2-acetyl-l-pyrroline. Rice bran contains: water 9.9%, gross energy 1940 kj (463 kcal) per 100 g, crude protein 13.8%, crude fibre 7.8%, ether extract 16.4%. After oil extraction, rice bran contains: water 9.8%, gross energy 1590 kj (380 kcal) per 100 g, crude protein 14.4%, crude fibre 9.3%, ether extract 3.1%. The husk forms about 20% of the unhusked grain weight, and is very rich in silica. Rice straw contains approximately: water 7.0%, protein 3.4%, fat 0.9%, carbohydrate 47.8%, fibre 33.4% and ash 7.5%. It is nutritionally inferior to other cereal straws unless ensiled. Rice straw is not particularly suitable for papermaking due to the high silica content (12 18%) and is used for this purpose mainly in countries where wood is scarce, e.g. in India and China. The ultimate fibre cells are (0.4-) 1.4(-3.4) mm long and (4-)9(-16) (im wide. Description Annual grass up to 1.8 m tall Oryza sativa - 1, plant base with roots; 2, ligule and auricles; 3, panicle with leaf; 4, flowering spikelet; 5, ovary with stigmas; 6, spikelet with mature grain. Source: PROSEA (up to 5 m long in some floating types), forming small tufts; roots fibrous, arising from the base of the shoots; stem (culm) erect or ascending from a geniculate base, terete, smooth, glabrous. Leaves alternate, simple; sheath coarsely striate, tight when young, later somewhat loose, often somewhat spongy, green or sometimes tinged with brown or purple, smooth, glabrous; ligule cm long, triangular, acute, entire or split, membranous, usually glabrous; auricles often present, falcate, 1-5 mm long, hairy; blade linear, tapering to an acute point, cm x cm, bright green to glaucous, glabrous or puberulous, smooth on the lower surface, slightly rough on the upper surface, midrib usually distinct. Inflorescence a terminal panicle up to 50 cm long, erect, curved or drooping, with spikelets; branches solitary or clustered, nearly erect to spreading. Spikelet solitary, asymmetrically oblong to elliptical-oblong, 7-11 mm x mm, with pedicel up to 4 mm long, 3-flowered but 2 lowest florets reduced to sterile lemmas 2-3 mm long; glumes small; lemma of fertile floret 6-10 mm long, boat-shaped, sometimes awned; palea

113 ORYZA 115 about as long as lemma; lodicules 2; stamens 6; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain), ovoid, ellipsoid or cylindrical, mm x mm, often whitish yellow or brown to brownish grey. Other botanical information Oryza comprises about 20 wild species distributed throughout the tropics and subtropics, and 2 cultivated species, Oryza sativa and Oryza glaberrima. In the most recent classification Oryza has been divided into 3 sections: sect. Pädia, sect. Brachyantha and sect. Oryza. Section Oryza is subdivided into 3 series: ser. Latifoliae, ser. Australiensis and ser. Sativae. Oryza sativa is classified in ser. Sativae, together with, among others, Oryza glaberrima, Oryza barthii A.Chev., and Oryza longistaminata A.Chev. & Roehr. Oryza glaberrima cultivars are grown only in Africa. Introgression of characters from Oryza glaberrima, Oryza barthii and Oryza longistaminata may have added new dimensions to the variability of Oryza sativa. Cultivated rice Oryza sativa is supposed to have evolved from perennial types (Oryza rufipogon Griff.) to annual types (Oryza nivara S.D.Sharma & Shastri, sometimes included in Oryza rufipogon). There is a natural gene flow between these 3 species, and they form a large species complex together with weedy forms of rice (popularly called 'red rice' because of their red endosperm). There are 2 major eco-geographical cultivar groups of Oryza sativa: Indica Group, which mainly includes cultivars from the tropics, and Japonica Group, which includes cultivars from temperate/subtropical areas. Traditional cultivars from Indica Group are tall, leafy, strongly tillering, and prone to lodging; they respond poorly to fertilization, particularly to nitrogen, and are sensitive to photoperiod; they are hardy, resistant to disease and tolerate unfavourable growing conditions; they will produce fair yields under conditions of low management. Modern Japonica Group cultivars are small, and are less tillering, less leafy, resistant to lodging, insensitive to photoperiod and are early maturing. The characteristics of the two cultivar groups have become less distinct because of the interbreeding programmes in recent years. Rice may also be classified according to the conditions under which it is grown, according to the size, shape and texture of the grain, or according to the period needed to mature. Growth and development Rice seed germinates in hours. The optimum temperature for germination is C. Most cultivars have a short dormancy or none at all, but in some it may last up to 4 months. Ten days after germination the plant becomes independent as the seed reserve is exhausted. Tillering begins thereafter, although it may be a week later in transplanted seedlings. In modern cultivars with an average maturation period, maximum tillering stage is attained around 45 days after transplanting and coincides with panicle initiation. The duration of the vegetative stage ranges from 7 to more than 120 days. The reproductive stage starts at panicle initiation, and the period from panicle initiation to flowering is around 35 days. Rice is almost 100% self-pollinating, but small amounts of cross pollination by wind do occur. It takes around 7 days to complete the anthesis of all spikelets in a panicle, starting from the top and progressing downwards. The period from flowering to full ripeness of all the grains in a panicle is usually about 30 days. Low temperature can delay maturity and high temperature accelerates it. Floating rice has a long maturation period of 7 months or more. Rice roots can grow under low oxygen concentrations. The roots are not typically aquatic as they are much branched and have a profusion of root hairs; later, spongy tissue (aerenchyma) develops in the cortex. Ecology Rice is grown as far north as 53 N in Moho, northern China and as far south as 35 S in New South Wales, Australia. It grows on dry or flooded soil and at elevations ranging from sea level to at least 2400 m. The average temperature during the growing season varies from C. Night temperatures below 15 C can cause spikelet sterility. Temperatures above 21 C at flowering are needed for anthesis and pollination. Upland rice requires an assured rainfall of at least 750 mm over a period of 3-4 months and does not tolerate desiccation. Lowland rice tends to be concentrated in flat lowlands, river basins and deltas. The average water requirement for irrigated rice is 1200 mm per crop or 200 mm of rainfall per month or an equivalent amount from irrigation. Relative humidity within the crop canopy is high, since there is standing water in most rice crops. A low relative humidity above the canopy during the dry season aggravated by strong winds can cause spikelet sterility. Traditional cultivars are generally photoperiod sensitive, and flower when daylengths are short (critical daylength of hours). Many modern cultivars are photoperiod insen-

114 116 CEREALS AND PULSES sitive. The soils on which rice grows vary greatly: texture ranges from sand to clay, organic matter content from 1-50%, ph from 3-10, salt content up to 1%, and nutrient availability from acute deficiencies to surplus. Rice does best in fertile heavy soils. The optimum ph for flooded soil is The often sandy texture of soils in tropical Africa is a constraint to productivity due to drought stress, low inherent soil fertility and leaching. Groundwater salinity problems occur in the dry Sahel zone where rice is grown under irrigation. In lowland coastal West Africa rice productivity is affected by saline water intrusion. The majority of mangrove swamp soils along the West African coast are furthermore potential or actual acid sulphate soils. In West Africa iron toxicity in valley bottoms is most severe in areas where the adjacent uplands are strongly leached Ultisols. Lowland rice and deep-water rice may be subjected to both drought or complete submergence. In submerged soil the ph tends to be neutral, i.e. the ph of acid soils increases whereas the ph of calcareous and sodic soils decreases. Ions of Fe, N and S are reduced, the supply and availability of the elements N, P, Si and Mo improve, whereas the concentration of water-soluble Zn and Cu decreases. Toxic reduction products such as methane, organic acids and hydrogen sulphide are formed. The flooding of rice soils also creates a favourable environment for anaerobic microbes and the accompanying biochemical changes. As a result, the decomposition rate of organic matter decreases. However, a thin surface layer generally remains oxidized and sustains aerobic microbes. Propagation and planting Rice is propagated by seed. The 1000-seed weight is g. The seed may either be broadcast or drilled directly in the field, or seedlings may be grown in nurseries and transplanted. Direct seeding is done in dry or puddled soil. In puddled soil the (pre-germinated) seeds are broadcast. After sowing the water level is kept at 0 5 cm under tropical conditions. In dry soil the seeds are sown just before or after land preparation. In the latter case the seeds are then covered lightly with soil. The seeds are sown just before the rains begin and germination occurs after heavy continuous rains. This method makes it possible to have initial crop growth from early rains. In tropical Africa various rice-growing systems are distinguished: - Upland rice, which may be subdivided into dryland rice, whereby moisture supply is entirely dependent on rainfall, and hydromorphic rice where the rooting zone is periodically saturated by a fluctuating water table, in addition to rainfall; - Lowland rice, including mangrove swamp rice along the coastal regions with tidal intrusion, inland swamp rice on flat or V- shaped valley bottoms with varying degrees of flooding, and rice on bunded fields under rainfed or irrigated conditions; - Deepwater rice, in which the rapid growth of the internodes keeps pace with the rising water up to 5 m or more, starting from 50 cm of standing water. In upland rice cultivation the fields are normally cleared through the slash-and-burn practice. Soil preparation is normally minimal. The rice is broadcast or dibbled when the rains start. It is often grown as the first crop in rotation or intercropped with other crops such as cassava, maize, sorghum, cowpea, groundnut and other pulse crops. In lowland rainfed-rice areas the land is mostly prepared while it is wet and only in rare occasions when it is dry. The wetland tillage method consists of soaking the land until the soil is saturated, ploughing to a depth of cm using a plough drawn by oxen/small machines or by using a hand hoe, preferably when there is a little water on the land, and harrowing, during which big clods of soil are broken and puddled with water. The important benefits of puddling include the apparent reduction of moisture loss by percolation, better weed control, and easy transplanting. In lowland rice cultivation seedlings are mostly raised on wet nursery beds and sometimes on dry nursery beds. Wet nursery beds are made in the puddled or wet field. Normally farmers use kg of rice seeds to plant one ha. Seeds are pregerminated and spread on the bed which is kept constantly wet. Dry nursery beds are prepared near the water source before land preparation. The seeds are sown and then covered with a thin layer of soil and watered until saturation for uniform germination. Further watering is applied as needed. In both cases the seedlings are ready for transplanting days after sowing. At transplanting heavy tillering cultivars in fertile valley bottoms are wider spaced (30 cm x 30 cm) than slightly tillering cultivars in upper, sandy fields (20 cm x 20 cm). The spacing in irrigated rice is normally 20 cm x 20 cm with 2 4 plants per hill

115 ORYZA 117 (500,000-1,000,000 plants/ha). Rice is generally a sole crop under lowland conditions. Near harvest, relay planting is rarely practised. In many parts of the tropics 2 or even 3 crops of rice can be grown per year. There is a lack of accurate data on the extent of different rice systems in tropical Africa. The upland rice ecosystem, including hydromorphic rice, accounts for an estimated 50% of the total rice area in tropical Africa; lowland rice cultivation, including mangrove swamp rice, inland swamp rice and irrigated rice, accounts for 45% of the total rice area; deep-water rice cultivation occupies the remaining 5%. Most rice is grown on smallholdings of ha. Management The agronomy of rice is diverse due to the differences in cultivation systems. Growing of upland rice is usually relatively labour-extensive, but transplanting rice by hand in puddled soil is a labour-intensive operation. Weeding is generally not necessary in the first 2 weeks. Manual weeding is common practice, although chemical weed control is also becoming popular in tropical Africa, especially in irrigated rice areas. Three timely weedings are normally necessary in broadcast rice. In the cultivation of lowland rice, the land is inundated from the time of planting until the approach of harvest. The water is supplied either by flooding during the rainy season, by growing the crop in naturally swampy land or by controlled irrigation. The water level is kept at a height of 5-15 cm to suppress weed growth and to ensure water availability. Continuous flooding at a static cm depth is best. The fields may be drained temporarily to facilitate weeding and fertilizing. At flowering the water level is gradually reduced until the field is almost dry at harvest. Generally m of water (rainfall plus irrigation) are required to produce a good crop. The period in which rice is most sensitive to water shortage is from 20 days before to 10 days after the beginning of flowering. Fertilizer application is limited in rice cultivation in tropical Africa. Only in irrigated rice with controlled water supply and modern cultivars do farmers generally use significant amounts of mineral fertilizers. The amount of fertilizer used is usually kg N, kg P and 0-30 kg K per ha. Higher nitrogen rates are used during the dry season when solar radiation is higher and increase in grain yield is larger. Generally, nitrogen fertilizer is only topdressed, mostly before or at panicle initiation. Fertilizer is broadcast by hand. The most common mineral deficiencies in rice cultivation are of nitrogen and phosphorus, with potassium and sulphur in limited areas and sometimes zinc and silicon on peaty soils. Deficiency of potassium is often associated with iron toxicity. Upland rice often suffers from sulphur deficiency. Zinc deficiency occurs regularly in rice areas because of the high ph and strong reduction of the soil. Influenced by reduction and poor internal drainage, several toxic elements such as iron, which inhibit the uptake of phosphorus in the plant, may accumulate in the environment of the root. Often a harmful excess of elements such as calcium is accompanied by a lack of other elements such as phosphorus, iron and zinc. Double cropping is inadvisable where physiological diseases occur. Green manure and Azolla are rarely used in tropical Africa. However, the fast growing and actively nitrogen-fixing Sesbania rostrata Bremek. & Oberm. is a promising green manure crop. Nitrogen fixation also takes place in paddy soils by Azotobacter and blue green algae (cyanobacteria). Organic fertilizers such as farmyard manure and compost are not commonly applied to rice crops in tropical Africa. Although soil conditions are normally improved by incorporating organic fertilizers, the result is not immediately apparent. Poor availability, transport problems and the high amount of labour involved also discourage its use. The degree of mechanization is in general limited in rice cultivation in tropical Africa. Occasionally farmers use tractors or small twowheel power tillers for land preparation and powered threshing machines during harvest. For various reasons many rice fields are left fallow in the dry season. In areas with suitable climatic and soil conditions for dry-season cultivation, rice may be rotated with crops such as other cereals, pulses and vegetables. Diseases and pests The most common and severe disease of rice in tropical Africa is blast (Pyricularia grisea, synonym: Pyricularia oryzae). Although this disease is often related to drought stress and therefore especially severe in upland and drought-prone areas, it may also be severe elsewhere. Low light intensity, nutritional imbalances (especially K-deficiency), excessive N-supply, and relatively low temperatures (20-28 C) are further factors favouring this disease. The blast fungus can infect rice leaves, nodes and floral parts, particularly the basal part of the panicle. Other important

116 118 CEREALS AND PULSES diseases of rice in tropical Africa are bacterial leaf blight (Xanthomonas oryzae pv. oryzae), rice yellow mottle virus (RYMV, only found in Africa), brown spot (Cochliobolus miyabeanus), leaf scald (Microdochium oryzae), sheath blight (Thanatephorus cucumeris), narrow brown leaf spot (Cercospora janseana) and sheath rot caused by Sarocladium oryzae. The use of resistant cultivars, the judicious application of N fertilizer, adjusted planting time, crop rotation and phytosanitary and quarantine measures limit losses from rice diseases. Chemical control for blast and other rice diseases is hardly used in tropical Africa. Nematodes attack roots and young, unfurled leaves and reduce rice production in certain parts of tropical Africa. Most insect species causing damage to rice in the field and to the grain during storage in tropical Africa are indigenous, and different from those found in Asia. Internal stem feeders such as stem borers, the stalk-eyed fly and gall midge generally cause the most severe damage. The most common species of stem borers in tropical Africa are white stem borer (Maliarpha separatella), pink stem borers (Sesamia spp.) and striped stem borer (Chilo spp.). Damage results from larvae feeding within the stem, severing the vascular system. Dead heart is the damage to the tiller before flowering. White head is the damage after flowering which causes the entire panicle to dry. The damage from the stalk-eyed fly (mainly Diopsis macrophthalma) resembles the dead heart damage from stem borers as it generally attacks the rice plant at the early tillering stage. The feeding of the gall midge maggot (Orseolia oryzivora) stimulates the leaf sheath to grow into a gall and tillers with galls do not bear panicles. Termites and mole crickets attack rice plants especially in rainfed upland rice. The most serious insect pests of stored rice are the rice weevil (Sitophilus oryzae) and the lesser grain borer (Rhyzopertha dominica). These insects can completely destroy the grain. Insects can be controlled by chemical, cultural, and biological methods. In tropical Africa farmers use insecticides but at far lower levels than in Asia. It is important to use various crop protection methods in an integrated pest management (IPM) system for rice in tropical Africa that is sustainable, inexpensive, and environmentally safe. It should combine the use of resistant cultivars, cultural methods, biological control and, finally, chemical control when pest damage threatens to exceed the economic injury threshold. Cultural methods include sanitation (the destruction of crop residues, of alternative hosts including weeds and of habitats), tillage and flooding of fields, crop rotation, intercropping, proper timing of planting and harvest, use of trap crops, and proper fertilizer and water management. Birds eat broadcast seeds, disturb young transplanted seedlings and eat rice grains; losses can be very high. Rodents attack rice at all stages of growth and also stored grain, and losses due to rodents are often serious. Less damage is caused by snails, crabs and shrimps. Parasitic weeds of the genus Striga may cause serious losses in upland rice, e.g. Striga aspera (Willd.) Benth. and Striga hermonthica (Delile) Benth. in West Africa, and Striga asiatica (L.) Kuntze in the Indian Ocean Islands. Harvesting Grain should be harvested before it is fully mature (around 21 24% moisture), usually about 30 days after flowering, or when 90% of the grains are firm and do not have a greenish tint. Wetting and drying cause grain cracking, cracks being formed more readily when the grain is quite hard. Harvesting by hand, the commonest method, is very labourintensive. In some areas a small knife is used, but in many areas farmers use a sickle to cut the panicles plus some or all of the culms. Mechanical harvesters are very rare in tropical Africa. The harvested rice plants are either allowed to dry in the field or bundled for processing in a selected area. Yield Average rice yields are 1.4 t/ha in tropical Africa, 4.1 t/ha in Asia and 4.0 t/ha in the world in general. Yields are generally higher during the dry season than during the wet season, and higher in lowland rice than in upland rice. The yield of upland rice varies between 0.5 and 1.5 t/ha in tropical Africa but may reach 4 t/ha in Latin America. Rainfed lowland rice is higher yielding than upland rice but may suffer a drastic reduction in years with drought or floods. In a rainfed bunded lowland rice area in Tanzania yields are 3-4 t/ha in good years, but can drop to 0.5 t/ha in bad years. Yields of irrigated lowland rice in tropical Africa are generally 3-6 t/ha. Yields in the deep-water rice areas are generally low ( t/ha), but they are more stable than in the upland rice areas of tropical Africa. Handling after harvest Threshing is generally done by hand, by beating the bundles on a stone or drum, or by beating the panicles with wooden sticks on a canvas. However, motorized and pedal-driven threshing machines

117 ORYZA 119 are becoming popular. Winnowing is usually done by shaking and tossing the grain on a basket-work tray with a narrow rim. Sometimes hand-winnowing machines are used. After winnowing, the grain is dried in the sun and is then ready for hulling or transport to the mill. Proper drying of the rice grains is important to prevent germination and rapid loss of quality. Optimum moisture content for storage is 12.5%. Rice grain is mostly stored in sacks after drying. Increase in fat acidity during improper storage reduces the eating quality. Temperature and humidity during storage affect rice quality. Rice for home consumption is stored unhusked, as it is less susceptible to deterioration. In rice milling the aim is to avoid breaking the kernels because whole kernels command a higher price. There are different methods of milling. On milling, the grain gives approximately: husk 20%, whole kernels 50%, broken kernels 16%, bran and meal 14%. The husked or hulled rice is usually called brown rice, and this is then milled to remove the outer layers, after which it is polished to produce white rice. During milling and polishing some of the protein and much of the fat, minerals and vitamins are removed, reducing the nutritional value but increasing storability and reducing cooking time. Parboiling (soaking, boiling and drying) before milling improves the nutrient value of the grains but it is not common in tropical Africa. Genetic resources The exploration and collection of germplasm of African wild and cultivated rice species was started in 1959 by Japanese researchers who were attracted by the great diversity. The earliest collections of rice genetic resources in West Africa were built up at research stations at Rokupr, Sierra Leone and Badeggi, Nigeria. Later on the French research institutes ORSTOM and IRAT started collecting rice germplasm from francophone countries and UTA, Ibadan, Nigeria, from mainly anglophone countries. A combination of these germplasm collections with almost 15,000 accessions was then established by WAR- DA at Bouaké, Côte d'ivoire. Most of these accessions are also available in the International Rice Germplasm Collection at the International Rice Research Institute (IRRI), Los Banos, the Philippines where the largest Oryza sativa collection is found with more than 86,000 accessions, characterized on the basis of about 80 traits. These traits not only include morphological characters but also susceptibility to diseases and pests, and reaction to environmental stresses, mineral deficiencies or toxicities. Large germplasm collections of Oryza sativa are also held in China (China National Rice Research Institute, Huangzhou, 70,000 accessions) and India (National Bureau of Plant Genetic Resources, New Delhi, 26,000 accessions). Apart from at WARD A, in tropical Africa large collections are present in Nigeria (International Institute of Tropical Agriculture (UTA), Ibadan, 9400 accessions; National Cereals Research Institute, Badeggi, 3500 accessions) and Madagascar (Département de Recherches Agronomiques de la République Malgache, Antananarivo, 2000 accessions). Collection of wild rices is being emphasized for possible new sources of important genes. Breeding Rice grain yields in the tropics have increased dramatically since the mid 1960s with the introduction of 'IR8' and other semi-dwarf cultivars, which do not lodge easily and allow high nitrogen fertilizer doses. In tropical Africa these green revolution cultivars are mainly used in irrigated rice with controlled water supply. Genetic improvement of rice in Africa was mainly focused on the upland crop. This has led to the 'New Rice for Africa' ('NERICA') cultivars, WARDA's major breakthrough in the early 1990s. 'NERICA' cultivars were the result of successful crossing of Oryza glaberrima with Oryza sativa. They combined higher tolerance to deep water, drought, weeds, blast and stalk-eyed fly from Oryza glaberrima with greater grain productivity and retention on the plant from Oryza sativa. 'NERICA' cultivars are proving to be popular with farmers, not only because of their growth characteristics, but also for their grain quality and nutritive value. They are further well suited to lowinput conditions. Breeding activities of WARD A on lowland cultivars have led to the release of cultivars with improved grain yield, resistance to blast and rice yellow mottle virus and tolerance to drought and iron toxicity. The improved cultivar 'Sahel 108', released in 1994 by WARDA, has a short life cycle enabling doublecropping in the irrigated rice systems in the Sahel. Wild Oryza species, such as Oryza barthii, Oryza longistaminata and Oryza punctata are useful sources of resistance to various biotic and abiotic stresses. For instance, resistance to bacterial leaf blight has successfully been transferred from Oryza longistaminata. Biotechnology techniques used in rice breeding include plant tissue culture, molecular biology and genetic engineering. Two tissue culture

118 120 CEREALS AND PULSES techniques, embryo rescue and anther culture, have already made important contributions. Saturated genetic linkage maps based on molecular markers have been developed for rice, using crosses between cultivars of Indica Group and Japonica Group, or between Oryza sativa and Oryza longistaminata. These maps have made possible the identification of QTLs for many useful traits, such as resistance to diseases and tolerance to drought. More than 3000 molecular markers are available now, making rice the best characterized crop. The project for sequencing the complete rice genome has recently been completed. Biotechnology's most novel contribution will probably be in adding alien genes to the rice gene pool through genetic engineering. One example is 'Golden Rice', which is rice enriched with vitamin A. It is, however, still not clear if this genetically modified rice will yield well, not be susceptible to diseases and pests and be palatable. Several insecticidal toxin genes from Bacillus thuringiensis (Bt) have been transferred to rice and plants containing Bt genes have shown substantial resistance to stem borers and leaf folders. Recently, transgenic rice has been obtained conferring resistance to sheath blight. Genetic engineering is a relatively new technology and one of the principal biosafety concerns is the spread of foreign genes by pollen dispersal from transgenic rice to other rice cultivars and wild rice species. Prospects At present, only an estimated 2% of the 200 million ha of wetlands in tropical Africa are used for lowland rice cultivation. Therefore one of the biggest challenges for rice development in tropical Africa is the utilization of the large potential for expansion of lowland rice. The emphasis of genetic improvement should be directed to lowland rice ecosystems, which have a higher production potential than upland rice, for example the breeding of crosses of Oryza sativa and Oryza glaberrima for lowland rice ecosystems. Any new types recommended should be well adapted to the local environment and methods of cultivation. For that matter it is advisable that in the breeding process greater use is made of farmer participatory varietal selection (PVS) and farmer participatory plant breeding (PPB). Breeding activities for tropical Africa should include tolerance of and adaptation to iron toxicity, salinity, alkalinity, acid sulphate soils, and relatively extreme cool and hot temperatures. In tropical Africa there is still much room for increased and integrated use of organic and mineral fertilizers with a higher efficiency and greater use of nitrogen-fixing legumes, bacteria and bluegreen algae. The applicability of methods of integrated soil fertility management (ISFM) in a certain locality can be best tested through farmer field schools. An increased use of farmer field schools is also advocated for the adoption of methods of integrated pest management (IPM) by more rice farming households in tropical Africa. Further improvements are expected from mechanization of rice farming, especially regarding land preparation, weeding, harvesting, threshing and further processing. All these suggestions require research adjusted to the local conditions, a well-functioning extension service, government support, and active participation of farming households. Some of the above topics are already being researched. Major references Alam, John & Zan, 1985; Buddenhagen & Persley (Editors), 1978; Catling, 1992; Grist, 1986; Lorieux, Ndjiondjop & Ghesquière, 2000; Meertens, Ndege & Lupeja, 1999; Schalbroeck, 2001; Smith & Dilday, 2003; Vergara & de Datta, 1996; Zan, John & Alam, Other references Abo, Sy & Alegbejo, 1998; Burkill, 1994; Catling & Islam, 1999; Chang, 2000; Choudhury & Kennedy, 2004; de Datta, 1981; de Vries & Toenniessen, 2001; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Holland, Unwin & Buss, 1988; Johnson et al., 1997; Jones et al., 1997; Khush, 1997; Latham, 2004; Launert, 1971; Lu, 1999; Neuwinger, 2000; Paul, Southgate & Russell, 1980; Sauvant, Perez & Tran, 2004; Vergara & Chang, 1983; Widjaja, Craske & Wootton, Sources of illustration Vergara & de Datta, Authors H.C.C. Meertens Based on PROSEA 10: Cereals. PANICUM KALAHARENSE Mez Protologue Bot. Jahrb. Syst. 57: 187 (1921). Family Poaceae (Gramineae) Origin and geographic distribution Panicum kalaharense is distributed in Zambia, Namibia, Botswana, Zimbabwe, Mozambique and South Africa. Uses The grain of Panicum kalaharense is eaten by the Wambo people in Namibia. Panicum kalaharense is also a pasture grass.

119 PANICUM 121 Properties As a pasture grass Panicum kalaharense is recorded as being moderately palatable when young. Botany Robust, perennial grass up to 2.5 m tall, tufted or with a short rootstock; stem (culm) pubescent at base. Leaves alternate, simple and entire; leaf sheath densely hairy along margins in upper part; blade linear, cm x 2-8 mm, acuminate, flat or rolled, tough, upper surface densely covered with short hairs. Inflorescence a broadly ovoid panicle cm long, moderately to much branched. Spikelet ovoid, 3-4 mm long, 2- flowered; lower glume broadly ovate, half to two-thirds the length of the spikelet, acute or acuminate, 3-5-veined, upper glume 5 9- veined; lower floret male, lemma 7-9-veined, palea well-developed, upper floret female, lemma and palea pale or dark, glossy; stamens 3; ovary superior, stigmas 2. Fruit a caryopsis (grain), ellipsoid, compressed. Panicum comprises about 470 species and is mainly distributed in tropical and subtropical regions, with some species extending to temperate regions. Panicum kalaharense follows the C4-cycle photosynthetic pathway. Ecology Panicum kalaharense is considered to be drought resistant. It is locally common in grassland and savanna habitats on sandy soils in areas with an annual rainfall of mm, at m altitude. It is also found in disturbed locations such as roadsides. Management The grain of Panicum kalaharense is collected from the wild. Genetic resources and breeding A small collection of 3 accessions of Panicum kalaharense is held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia. Prospects Panicum kalaharense is an unimportant local source of food and forage, and will probably remain so. Little is known about this species and more information would be useful, particularly on its food and fodder quality. Major references Clayton, 1989; Gibbs Russell et al, 1990; Launert, Other references Klaassen & Craven, 2003; Schulze et al., Authors M. Brink PANICUM LAETUM Kunth Protologue Révis. gramin. 2: 399, f. 113 (1831). Family Poaceae (Gramineae) Vernacular names Wild fonio, desert panic (En). Haze, fonio sauvage (Fr). Origin and geographic distribution Panicum laetum is distributed from Mauritania, Senegal and Gambia eastwards through the southern Sahara and the Sahel to Eritrea; it is also recorded from Tanzania. Uses Panicum laetum is one of the 'kreb' grasses, a group of grasses occurring in the Sahel and collected from the wild for human consumption on a regular basis and especially in times of food shortage; it is also regarded as a delicacy. The grain of Panicum laetum is crushed and made into porridge and cakes, and is sometimes collected on a large enough scale to be sold in local markets. Panicum laetum is much appreciated by animals for grazing and is suitable for making hay or silage. It is considered to have potential for the restoration of degraded pastures. Properties Whole grains of Panicum laetum collected in Mali contained per 100 g: water 3.3 g, energy 1580 kj (377 kcal), protein 9.5 g, fat 4.8 g, carbohydrate 70.8 g, Ca 51 mg and Fe 210 mg. The essential amino acid content of whole grains per 16 g N was: tryptophan 1.3 g, lysine 2.0 g, methionine 2.6 g, phenylalanine 5.9 g, threonine 3.7 g, valine 6.0 g, leucine 11.3 g and isoleucine 4.7 g. Husked grains contained per 100 g: water 1.9 g, energy 1630 kj (389 kcal), protein 12.4 g, fat 2.2 g, carbohydrate 82.1 g, ash 1.4 g, Ca 13 mg and Fe 24 mg. The essential amino acid content of husked grains per 16 g N was: tryptophan 1.4 g, lysine 1.3 g, methionine 2.6 g, phenylalanine 6.3 g, threonine 3.6 g, valine 6.0 g, leucine 12.2 g and isoleucine 5.1 g (Beseth Nordeide, Holm & Oshaug, 1994). The most limiting amino acid is lysine. Panicum laetum plants in mid-bloom in Niger contain crude protein 14.3%, crude fibre 28.8%, crude fat 1.8%, nitrogen-free extracts 42.9%, Ca 0.30%, Mg 0.28% and P 0.42%. Botany Annual, tufted grass up to 75 cm tall; stem (culm) slender, erect or geniculately ascending, branched. Leaves alternate, simple and entire; leaf sheath glabrous or bristlyhairy; ligule short, fringed; blade linearlanceolate, flat, 5-25 cm x 5-12 mm, acuminate, usually glabrous, margin smooth or bristly hairy in lower part. Inflorescence an ovoid

120 122 CEREALS AND PULSES panicle 6-20 cm long, much-branched, primary branches ascending or spreading, branchlets and pedicels slender. Spikelet narrowly ellipsoid, mm x 1.5 mm, acute, usually pale green, 2-flowered; lower glume ovate, about % the length of the spikelet, 5-7-veined, acute, upper glume elliptical, 7 11-veined, acute; lower floret sterile, lemma 9-11-veined, palea almost equally long, upper floret bisexual, lemma narrowly ovate, acute, pale, smooth, glossy; stamens 3; ovary superior, stigmas 2. Fruit an ellipsoid caryopsis (grain) mm long, compressed, yellowish. Panicum comprises about 470 species and is mainly distributed in tropical and subtropical regions, with some species extending to temperate regions. Ecology Panicum laetum is found in seasonally moist locations in grassland, ditches, and pond and river margins, often on black clay soils. It is not particularly drought tolerant. In West Africa Panicum laetum often occurs in very large, nearly pure stands. In Tanzania it is found at m altitude. Management Panicum laetum is propagated by seed. The optimum temperature for seed germination is 35 C. Scarification or removal of the lemma and palea from the grain greatly improves germination. In West Africa Panicum laetum is collected from the wild by sweeping through the crop with a calabash, bowl or tray when the ears are ready to shatter. The grains of Panicum laetum are favoured by quelea birds. Genetic resources and breeding A collection of 25 accessions of Panicum laetum is held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia. In view of its wide distribution and abundance Panicum laetum is not threatened by genetic erosion. Prospects Panicum laetum is of importance in marginal areas and has potential for restoring over-grazed pastures. The selection of improved strains for grain and fodder production is recommended. Major references Beseth Nordeide, Holm & Oshaug, 1994; Burkill, 1994; Naegele, 1977; National Research Council, 1996; Phillips, Other references Bartha, 1970; Clayton, 1972; Harlan, 1989b; Keith & Plowes, 1997; le Grand, 1979; van der Hoek & Jansen, 1996a; Veldkamp, 1996b; Veldkamp, Wijs & Zoetemeyer, Authors M. Brink PANICUM MILIACEUM L. Protologue Sp. pi. 1: 58 (1753). Family Poaceae (Gramineae) Chromosome number ïn = 36 Vernacular names Proso millet, common millet, hog millet (En). Millet commun, kibi (Fr). Milho miudo, milho de canario (Po). Origin and geographic distribution Proso millet is of ancient cultivation. Its origin has not been ascertained, but it was probably domesticated in central and eastern Asia, where it has been cultivated for more than 5000 years. Proso millet has long been a major crop in northern China. In the Bronze Age it spread widely in Europe, also to northern regions where the cold-susceptible foxtail millet (Setaria italica (L.) P.Beauv.) could not be grown. In Europe remains have been found in agricultural settlements dating back about 3000 years. Proso millet was the 'milium' of the Romans and the true millet of history. It was introduced into North America after the arrival of Columbus. In Europe and the United States its popularity as a cereal declined after the large-scale introduction of potato and maize. Nowadays proso millet is cultivated for human consumption mainly in eastern and central Asia, and to a lesser extent in eastern Europe (Russia, Danube region) and from western Asia to Pakistan and India (Bihar, Andhra Pradesh). It is occasionally grown in other parts of Europe and Asia and in North America, mainly as a source of feed for cage-birds and poultry, and as fodder. In tropical Africa, it is cultivated in Ethiopia, eastern Kenya, Malawi, Botswana, Zimbabwe and Madagascar. It is also recorded from Lesotho. Its importance in Kenya is said Panicum miliaceum -planted

121 PANICUM 123 to have declined since the 1950s following the advance of maize cultivation. Proso millet has widely naturalized, and is sometimes a troublesome weed, e.g. in the United States and Russia. Uses The husked grains of proso millet are eaten whole, boiled like rice or after roasting. They are also cooked into porridge, or, after grinding, baked into flat bread or chapatti. Only the flour of gluten-rich types can be used for leavened bread and cakes; the flour of other types has to be mixed with wheat flour. In China, where proso millet flour is made into bread, cultivars with glutinous (waxy) endosperm are favoured; in Mongolia, where the grains are cooked like rice, non-glutinous cultivars are grown. In Ethiopia, the grains are fermented into a kind of beverage ('tella'). Elsewhere they are used for making beer and brandy. The grain is a feed for animals, including pigs, fowls and cage-birds. The plant is used as a forage. The forage quality of the straw is poor, and in India it is more often used for bedding for cattle. The straw is also made into brooms. Starch from the grains has been used for sizing textiles. Various medicinal uses of proso millet have been recorded in Asia; the seeds are used as a demulcent and as a treatment for abscesses and boils, and stem and root decoctions are taken against haematuria. Production and international trade Production statistics for proso millet are scarce because they are usually lumped with those of other millets. The average annual world production of proso millet in was estimated at 4.9 million t, with the Soviet Union (2.3 million t), China (1.6 million t) and India (0.5 million t) as main producers. The annual production in was estimated at 4 million t. In tropical Africa the production of proso millet is very low compared to that of pearl millet (Pennisetum glaucum (L.) R.Br.) and finger millet (Eleusine coracana (L.) Gaertn.), but no statistics are available. Compared to the total world trade in cereals, the international trade in millets is insignificant. The world millet trade in amounted to about 250,000 t/year. The share of proso millet of the total recorded millet trade has been estimated at about two-thirds. Most proso millet traded internationally is imported by the pet-food industry in industrialized countries for use as bird feed. As millet yields are relatively low, prices on the world market are generally higher than those of other cereals; the small size of the international millet trade results in volatile prices. Properties Proso millet contains per 100 g edible portion: water 8.6 g, energy 1582 kj (378 kcal), protein 11.0 g, fat 4.2 g, carbohydrate 72.9 g, dietary fibre 8.5 g, Ca 8 mg, Mg 114 mg, P 285 mg, Fe 3.0 mg, Zn 1.7 mg, vitamin A 0 IU, thiamin 0.42 mg, riboflavin 0.29 mg, niacin 4.7 mg, vitamin P> mg, folate 85 ug, ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 119 mg, lysine 212 mg, methionine 221 mg, phenylalanine 580 mg, threonine 353 mg, valine 578 mg, leucine 1400 mg and isoleucine 465 mg. The principal fatty acids are (per 100 g edible portion): linoleic acid 2015 mg, oleic acid 739 mg, palmitic acid 528 mg, stearic acid 145 mg and linolenic acid 118 mg (USDA, 2004). The grains have a relatively high indigestible fibre content because the seeds are enclosed in hulls which are difficult to remove by conventional milling processes. The husked grain of proso millet has a slightly nutty flavour. Panicum miliaceum - 1, upper part of flowering culm of plant type with loose inflorescence; 2, inflorescence branch of plant type with loose inflorescence; 3, upper part of flowering culm of plant type with compact inflorescence; 4, inflorescence branch of plant type with compact inflorescence; 5, grains. Source: PROSEA

122 124 CEREALS AND PULSES Non-glutinous proso millet cultivars are considered suitable for the diet of people with coeliac disease. Experiments with rats indicate that proso millet protein may be useful as a preventive food for certain types of hepatitis. Proso millet has been found to induce allergic reactions in bird keepers. Description Erect annual grass up to 1.2( 1.5) m tall, usually free-tillering and tufted, with a rather shallow root system; stem cylindrical, simple or sparingly branched, glabrous to variously hairy. Leaves alternate, simple; leaf sheath variously hairy; ligule membranous, c. 1 mm long, ciliate; blade linearlanceolate, cm x cm, variously hairy, with 3-6 veins on each side of the midrib. Inflorescence a slender panicle 10-30(-45) cm x 5-15 cm, open or compact, erect or drooping. Spikelets solitary, stalked, ovoid-ellipsoid, 4-6 mm long, 2-flowered, glabrous; glumes unequal, the upper as long as spikelet, manyveined; lower floret sterile, upper one bisexual with thick broad (c. 2 mm) lemma and palea, 2 lodicules, 3 stamens and superior ovary with 2 plumose stigmas. Fruit a caryopsis (grain), broadly ovoid, up to 3 mm x 2 mm, smooth, variously coloured but often white, enclosed by the persistent lemma and palea and shedding easily. Other botanical information Panicum is a large genus comprising about 470 species and is mainly distributed in tropical and subtropical regions, with some species extending to temperate regions. Panicum miliaceum is a complex species with wild and cultivated types. In the literature the following two groups have been classified as subspecies: subsp. ruderale (Kitag.) Tzvelev including all spontaneous types, wild and weedy, and subsp. miliaceum comprising the cultivated types. The cultivated types have sometimes been classified into a cultivar group: Proso Millet Group. The wild types have lax panicles, usually jointed spikelet stalks and narrow lemmas, whereas the cultivated ones have either lax or compressed panicles, spikelet stalks without joints and wider lemmas. The true wild type is native to central China and is considered to be the ancestor of the cultivated types. In temperate regions of Europe, Asia and the United States, however, wild types occur that differ from the wild type in China and are most probably derivatives of cultivated types which have regained the ability of natural seed dispersal and spread as weeds. Cultivated proso millet comprises many cultivars and landraces, and 5 groups have been distinguished, mainly based on size and shape of the inflorescences. Within these groups, cultivars are mainly distinguished on the basis of grain colour (varying largely from white, yellow, brown, red, to almost black) and ecological adaptation. Growth and development Proso millet matures in days. Emergence of the seedling is usually in 4-8 days after sowing. During the vegetative phase, which is usually completed days after sowing, tillering occurs and the inflorescence primordia are initiated. From then it takes days to flowering of the main culm, but this period is somewhat shorter at higher temperatures. It is accompanied by an increase in leaf area and rapid elongation of stem internodes. The leaf number on the main culm differs among cultivars, but each cultivar produces a fixed number of leaves before flowering. Flowering proceeds from top to bottom. The flowers are normally selffertilized, but cross-fertilization frequently exceeds 10%. The period from flowering to grain maturity has a duration of about days, and is almost constant among cultivars. At grain maturity the lower part of the inflorescence as well as the stem and leaves are still green. Proso millet follows the Ci-cycle photosynthetic pathway. Ecology Although proso millet is primarily a crop of temperate regions, it has a wide adaptability and can be grown in climates which are too hot and dry, and on soils which are too shallow and poor for successful cultivation of other cereals. It is cultivated further north than any other millet, the limit being the June isotherm of 17 C and the July isotherm of 20 C. Cultivation as a grain crop occurs up to 3000 m altitude in the Himalayas. It susceptible to frost. Proso millet has one of the lowest water requirements of all cereals. An average annual rainfall of mm is sufficient, of which 35-40% should fall during the growing period. Most soils are suitable for proso millet, except coarse sand. Propagation and planting Proso millet is propagated by seed. The 1000-seed weight is (4.7-)5(-7.2) g. Proso millet seeds germinate well at temperatures of C, with the highest rate at temperatures between 35 C and 40 C. The seed is either broadcast or drilled in rows cm apart and at a distance of 7.5 cm in the row. This corresponds with a seed rate of 8-12 kg/ha. The recommended seed rate for furrow planting in Kenya is 4 kg/ha, with a

123 PANICUM 125 row distance of 30 cm and 10 cm between plants within the row. The seedbed should be moist, firm and free of weeds. For optimal germination seed should be soaked in water for 24 hours and planted no deeper than 4 cm. In India the crop is sometimes grown from transplanted seedlings. Sowing early in the rainy season is less important for proso millet than for cereals such as sorghum and pearl millet, as yield reduction due to late sowing is relatively small. Proso millet is usually grown as a sole crop, but may be intercropped with other cereals and with pulses. In-vitro regeneration of proso millet is possible on Murashige and Skoog medium, using excised embryos, shoot tips and segments of young inflorescences. Management The first weeks after sowing are critical in proso millet cultivation, as initial growth is slow, thus making competition with weeds difficult. In Kenya the first weeding of proso millet is recommended to take place at 2-3 weeks after emergence of the seedlings, and the second 2 weeks later. Little is known about the fertilizer response of proso millet. In India recommended fertilizer rates are kg N, 20 kg P and 0-20 kg K per ha. Proso millet is usually grown as a rainfed crop, but in India it is sometimes irrigated. In Russia proso millet is usually grown in rotation with a forage grass, wheat or barley. In Bangladesh the rotation may comprise a pulse, wheat, jute, rice, potato or a Brassica crop. Diseases and pests Proso millet is relatively little affected by diseases and pests. The most important disease is smut (Sphacelotheca destruens and Ustilago spp.). Control measures include seed treatment with fungicide (copper sulphate) and crop rotation. Other diseases recorded are anthracnose (Colletotrichum graminicola), leaf blast (Pyricularia grisea), downy mildew (Sclerospora graminicola), ergot (Claviceps spp.), rust (Puccinia and Uromyces spp.), leaf blight (Helminthosporium sp.) and foot rot (Sclerotium rolfsii). The bacterium Xanthomonas holcicola can cause melanopathy, a darkening of the endosperm. Proso millet can be damaged severely by maggots of the shootfly (Atherigona miliaceae), which attack the growing point. Infestation usually begins in the seedling stage, but may also occur in older plants. Tolerant lines have been identified in India. Other pests that are sometimes troublesome include stem borers (Chilo partellus, Chilo suppressalis and Sesamia inferens), midges, bugs, army worms, grasshoppers and termites. Birds and rats may destroy a considerable part of the harvest. Harvesting Proso millet is ready for harvest when the seed has a moisture content of 14 15%. Delayed harvesting should be avoided, as the seed shatters easily if allowed to become too mature. Premature harvesting, on the other hand, results in reduced yield and quality. Plants are usually harvested by pulling them up by the roots, and they are threshed immediately to avoid grain loss. If proso millet is harvested during the rainy season with high relative humidity, the grain must be dried to 14% moisture content. Households usually dry the grains over fire. Yield The average yield of proso millet under rainfed conditions is kg/ha. With sufficient rain and fertile soils or under irrigation and with application of fertilizers, yields of over 2 t/ha have been obtained. The milling recovery is 70-80%. Handling after harvest Proso millet grain stores well for up to 5 years. Because of its small size it is hardly susceptible to insect attack. In India it is stored in granaries with clay walls or clay jars; sometimes the grain is mixed with ash or slightly baked before storage. It should be stored at 13% moisture content or less. Genetic resources The largest germplasm collections of Panicum miliaceum are held in Russia (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, about 9000 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, about 7500 accessions) and Ukraine (Institute of Plant Production, Kharkiv, about 5000 accessions; Ustimovskaya Experimental Station for Plant Cultivation, Ustimovka, about 3500 accessions). In tropical Africa, accessions are held in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu). In China, proso millet germplasm is being evaluated for resistance to smut, salt tolerance and nutritional quality. Of 4200 accessions described in China, 53% were nonglutinous. Breeding In Kenya some selection work with local lines and lines obtained from ICRISAT has been carried out. The recommended cultivar in Kenya is 'KAT/PRO-1', developed by Kenya Agricultural Research Institute (KARI). It was selected from 'N40101', an introduction from the former Soviet Union, received through ICRISAT. 'KAT/PRO-1' was derived from single plants selected for erect

124 126 CEREALS AND PULSES tillers, large inflorescences and large grains, and repeated cycles of mass selection of the progeny for the same traits and high yield potential. This cultivar is self-pollinated, has an open inflorescence and cream-coloured grains. It has the ability to stop growing when under severe drought stress, but it recovers quickly and resumes growth when the source of the stress is removed. It can be grown up to 2000 m altitude, becomes about 80 cm tall, flowers in days, and matures in days, depending on altitude and season. The average yield of 'KAT/PRO-1' was 1400 kg/ha, which was 50% higher than the mean of the local cultivar s. Breeding programmes in India and Russia aim at a higher productivity (drought resistance and earlier or late maturity), disease resistance (especially to smut) and grain quality (uniform size and shape, yellow endosperm with high carotenoid content). The main breeding method employed in Russia is intraspecific hybridization. The floral morphology of proso millet (small florets with tightly held lemma and palea) makes emasculation prior to anthesis and artificial crossing difficult, but techniques were developed in the United States and a number of cultivars have been released since In the United States breeding efforts include the development of cultivars with higher yield, better harvestability and large grain. In addition, germplasm with waxy starch characteristics (used for steam breads in South-East Asia) is being developed, to expand the export potential for proso millet in the United States. Interspecific crossing of Panicum miliaceum with some other Panicum species resulted in abnormal embryos, which could be rescued by in-vitro ovary culture. Pollen sterility of the hybrid progeny could partly be overcome by invitro propagation. Prospects The production of proso millet is declining and the crop is being replaced in the human diet by other cereals, especially rice, wheat and maize. However, it will continue to be an important staple in semi-arid areas where hardly any other cereal can be grown. Proso millet is considered a potentially useful quick-maturing crop for the drier regions of tropical Africa, to fill the hunger gap before the main cereals are harvested. Major constraints are low returns due to high labour requirements (mainly for bird scaring, but also for planting and weeding) and low yields, limited alternative uses, existing eating habits, and a lack of information on the crop. Measures resulting in less tillering, e.g. narrow distances between rows, give a more uniform crop maturity and will reduce labour requirements for bird scaring. The export market for millets in general will remain small, as millet prices tend to be too high compared with those of other cereals. Further development of niche markets, e.g. waxy starch for Asian markets, may improve the export potential of proso millet. Major references Cardenas, Nelson & Neild, 1984; FAO, 1995; Fröman & Persson, 1974; Hülse, Laing & Pearson, 1980; Ministry of Agriculture and Rural Development, 2002; M'Ragwa & Watson, 1994; Penninkhoff, 1984; Riley et al. (Editors), 1993; Seetharam, Riley & Harinarayana, 1990; van der Hoek & Jansen, 1996b. Other references Bajaj, Sidhu & Dubey, 1981; Baltensperger, 1996; Baltensperger, 2002; Bohle et al, 2003; CSIR, 1966; de Wet, 1995c; Douglas, 1974; Gibberd, 1996; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Haq, 1989; ICRISAT & FAO, 1996; Kashin et al., 1997; M'ragwa & Kanyenji, 1987; Nelson, 1984; Nishizawa et al., 2002; Petr et al., 2003; Purseglove, 1972; Seetharam, 1998; USDA, 2004; Veldkamp, 1996b. Sources of illustration van der Hoek & Jansen, 1996b. Authors R.N. Kaume Based on PROSEA 10: Cereals. PANICUM TURGIDUM Forssk. Protologue Fl. aegypt.-arab.: 18 (1775). Family Poaceae (Gramineae) Chromosome number 2n = 18, 36, 54 Vernacular names Desert grass, turgid panic grass (En). Origin and geographic distribution Panicum turgidum is distributed from Mauritania and Senegal eastwards through the Sahara and Sahel to Sudan, Ethiopia, Eritrea and Somalia, and through northern Africa and western Asia to Pakistan and India. Uses Panicum turgidum is one of the 'kreb' grasses, a group of grasses occurring in the Sahel region and collected from the wild for human consumption on a regular basis and especially in times of food shortage. Formerly the grains of Panicum turgidum were gathered in large amounts, but nowadays they are rarely harvested. The grains are mainly made into

125 PANICUM 127 porridge. They may also be pounded and eaten without further preparation ('tebik'). In Djibouti the young shoots are eaten; they are said to be sweet. When green, Panicum turgidum is eaten by all livestock; when dry, only by camels and donkeys. The stems are used for thatching and for making mats, baskets and cordage. The Tamachek people in Niger weave the straw as the weft, with thin threads of leather as the warp, into mats which can only be rolled one way. Mats of Panicum turgidum have been used as funeral shrouds. In the Sahara the stems are used as fuel. Plant ash is mixed with tobacco for chewing and in southern Algeria the powder of ground stems is used as a wound-dressing. In Mauritania the grains are credited with antidiabetic properties. Panicum turgidum has occasionally been used for dune fixation in arid areas. Properties The palatibility of the leaves of Panicum turgidum is low, but sufficient for camels and donkeys, and, when young, for sheep and goats. Herdsmen in Niger say that milk becomes foul-smelling 2-3 days after cows have grazed Panicum turgidum. The grains thresh free from the glumes but remain covered by the tough lemma and palea. Botany Much-branched, glaucous, perennial grass, forming rounded tussocks up to 1.5(-2) m tall and wide, with a thick rootstock and a fibrous root system up to 2 m deep and laterally spreading for up to 3.5 m; stem (culm) erect or ascending, woody, rooting at the nodes. Leaves alternate, simple and entire; blade linear-lanceolate, up to 20(-30) cm x 7 mm, often much shorter than the sheath, flat, folded or inrolled, stiff and pungent. Inflorescence a moderately branched, pyramidal panicle (-30) cm x 5 9 cm, lax, primary branches distant, eventually spreading. Spikelet ovoid, ( 5) mm long, acute or acuminate, swollen, glabrous, often gaping at anthesis, 2- flowered; glumes broadly ovate, acute to acuminate, lower glume slightly shorter than the spikelet, 5 9-veined, upper glume 7-9-veined; lower floret male, lemma 9-11-veined, palea well-developed, upper floret bisexual, lemma pale or yellowish, smooth, glossy; stamens 3; ovary superior, stigmas 2. Fruit a caryopsis (grain) c. 2 mm long, reddish. Panicum comprises about 470 species and is mainly distributed in tropical and subtropical regions, with some species extending to temperate regions. Natural reproduction of Panicum turgidum is mainly vegetatively by stolons. In dry areas the dormant buds sprout rapidly after the onset of the rainy season and the plants stay green over a very extended period, with flowering occurring towards the end of the rainy season and during the early part of the dry season. The seeds of Panicum turgidum mature at different times over an extended period, shatter easily and are often eaten by birds. Panicum turgidum follows the C4-cycle photosynthetic pathway. Ecology Panicum turgidum is extremely drought tolerant, growing in regions with an annual rainfall of mm or sometimes even less. It occurs up to 3200 m altitude, in sandy deserts and semi-deserts, on dunes and seashores, and in sandy pockets in rocky outcrops. Panicum turgidum is an important plant of the Sahara and Arabian deserts, catching sand and forming hummocks, sometimes in nearly pure stands. In Sudan it is dominant on grounds where locusts lay their eggs, and it serves as food for young locusts. Panicum turgidum tolerates saline soils. Management Panicum turgidum is not cultivated as a cereal, but collected from the wild. It is sometimes protected from grazing until after seed harvesting, e.g. in southern Algeria and northern Mali. The panicles may be beaten with a stick to obtain the grains. In Niger the panicles are rubbed between the hands. Panicum turgidum can be propagated by seed or by rootstock cuttings. Seeds do not germinate below 15 C and must be sown superficially. Germination is best at C. Transplanting of seedlings is possible. Genetic resources and breeding A collection of 42 accessions of Panicum turgidum is held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia. High grain-yielding types are particularly found in the Middle East. Because of its wide distribution and abundance Panicum turgidum is not threatened by genetic erosion. Prospects Panicum turgidum has value as a very drought-resistant grass suitable for sand-binding and for providing food and fodder. It is recommended to sample the existing variation and to use the collected germplasm in a breeding programme aimed at developing superior cultivars. More information is needed on the nutritional characteristics of the grain. Major references Burkill, 1994; Harlan, 1989b; Kernick, 1992; Phillips, 1995; Williams & Farias, Other references Ahmad et al., 1994; Bogdan, 1977; Clayton, 1972; Cope, 1995; Hanelt &

126 128 CEREALS AND PULSES Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Haroun, 2000; Kernick, 1978; Kiambi, 1999; Naegele, 1977; National Research Council, Authors M. Brink PENNISETUM GLAUCUM (L.) R.Br. Protologue Prodr.: 195 (1810). Family Poaceae (Gramineae) Chromosome number 2n = 14 Synonyms Pennisetum spicatum (L.) Körn. (1885), Pennisetum americanum (L.) Leeke (1907), Pennisetum typhoides (Burm.f.) Stapf & C.E.Hubb. (1933). Vernacular names Pearl millet, bulrush millet, cattail millet (En). Mil, mil à chandelle, mil pénicillaire, petit mil (Fr). Milho zaburro, milho preto, milheto, massango liso (Po). Mwele (Sw). Origin and geographic distribution Pearl millet was domesticated in the Sahel years ago from Pennisetum violaceum (Lam.) Rich. It spread to East Africa and from there to southern Africa, and, about 3000 years ago, to the Indian subcontinent. It reached tropical America in the 18 th century and the United States in the 19 th century. Pearl millet is commonly grown as a grain crop in the semi-arid regions of West Africa and the driest parts of East and southern Africa and the Indian subcontinent. It is also grown as a fodder crop, e.g. in Brazil, the United States, South Africa, and Australia. Uses Pearl millet is the staple food for over 100 million people in parts of tropical Africa and India. Decorticated and pounded into flour Pennisetum glaucum -planted it is consumed as a stiff porridge ('tô') or gruel in Africa, or as flat unleavened bread ('chapatti') in India. In Africa there are various other preparations such as couscous, rice-like products, snacks of blends with pulses, and fermented and non-fermented beverages. In several Indian preparations parched seeds are used. The stems are widely applied for fencing, thatching and building, as fuel and as a poorquality fodder. Split stems are used for basketry. A dye for leather and wood is obtained from red- and purple-flowered types. In African traditional medicine the grain has been applied to treat chest disorders, leprosy, blennorrhoea and poisonings, and the ground grain as an anthelmintic for children. A root decoction is drunk to treat jaundice; the vapour of inflorescence extracts is inhaled for respiratory diseases in children. In some areas the grains are used in rituals. Outside Africa and India pearl millet is mostly grown as a green fodder crop for silage, hay making and grazing. Following the discovery that pearl millet can suppress root-lesion nematodes (Pratylenchus penetrans) it is increasingly being used as an alternative to soil fumigation in tobacco and potato cropping in Canada. Production and international trade Production statistics often combine data on all millet species. Estimates based on total millet production (FAO statistics) and relative importance of pearl millet in different countries indicate an annual grain production of about 18 million t from a planted area of 26.5 million ha mostly in the dry regions of Africa (60% of area and 58% of production) and the Indian subcontinent (38% of area and 41% of production). Production statistics over the past 10 years show a 20% increase in area planted in Africa, with a 12%> increase in yield. Most of the area increase is in Burkina Faso, Chad, Mali, Niger and Nigeria, but yield levels increased only in the latter two countries. During the same period, the area planted to pearl millet in India declined by 16%, but yield levels increased by 30%. Negligible quantities are traded internationally. Properties Whole dried grain of pearl millet contains per 100 g edible portion: water 12.0 g, energy 1428 kj (341 kcal), protein 10.4 g, fat 4.0 g, carbohydrate 71.6 g, fibre 1.9 g, Ca 22 mg, P 286 mg, Fe 20.7 mg, ß-carotene traces, thiamin 0.30 mg, riboflavin 0.22 mg, niacin 1.7 mg and ascorbic acid 3 mg (Leung, Busson & Jardin, 1968). The content of essential amino acids per 100 g food is: tryptophan 189 mg,

127 PENNISETUM 129 lysine 332 mg, methionine 239 mg, phenylalanine 467 mg, threonine 374 mg, valine 535 mg, leucine 927 mg and isoleucine 397 mg (FAO, 1970). From a nutritional viewpoint pearl millet is better than maize and sorghum. Compared to that of other millets, the protein of pearl millet is rich in tryptophan. Description Robust annual grass up to 4 m tall, with basal and nodal tillering; root system extremely profuse, sometimes the nodes at ground level produce thick, strong prop roots; stem slender, 1-3 cm in diameter, solid, often densely villous below the panicle, nodes prominent. Leaves alternate, simple; leaf sheath often hairy; ligule short, membranous, with a fringe of hairs; blade linear to linearlanceolate, up to 1.5 m x 8 cm, often pubescent, margins minutely toothed, somewhat rough. Inflorescence a cylindrical, contracted, stiff and compact panicle, suggesting a spike, up to 200 cm long; rachis cylindrical, bearing densely packed clusters of 1 5( 9) spikelets, subtended by a tuft (involucre) of up to 90 bristles about as long as spikelets, but in some cultivars with a few stiff bristles up to 2 cm long. Spikelets Pennisetum glaucum - 1, plant habit; 2, part of infructescence; 3, pair of spikelets surrounded by involucre of bristles. Source: PROSEA obovate, 3-7 mm long, usually 2-flowered; glumes 2, lower one c. 1 mm long, upper one c. 2.5 mm; lower floret male or sterile, upper one bisexual; lemma ovate, pubescent on margins; palea almost as long as lemma; lodicules absent; stamens 3, anthers 2-5 mm long, tipped with brush-like bristles; ovary superior, obovoid, smooth, with 2 hairy stigmas, connate at the base. Fruit a free-threshing caryopsis (grain), globose to cylindrical or conical, mm long, variously coloured, from white, pearl-coloured or yellow to grey-blue or brown, occasionally purple, hilum marked by a distinct black dot at maturity. Other botanical information Pennisetum comprises about 80 species and occurs throughout the tropics. Pearl millet is not closely related to most other Pennisetum species, although it hybridizes easily with elephant grass (Pennisetum purpureum Schumach., a tetraploid with In = 28). Pennisetum glaucum belongs to a complex of 3 taxa that hybridize freely and are sometimes considered as subspecies of Pennisetum glaucum. However, as long as the complicated taxonomy of pearl millet has not been fully cleared up, it is preferable to keep these taxa separate: - Pennisetum glaucum: cultivated types, with persistent, stiped involucres; the dense inflorescences and non-shattering habit are conspicuous. - Pennisetum sieberianum (Schltdl.) Stapf & C.E.Hubb. (synonyms: Pennisetum stenostachyum (A.Braun & Bouché) Stapf & CE. Hubb., Pennisetum dalzielii Stapf & CE. Hubb., Pennisetum americanum (L.) Leeke subsp. stenostachyum (A.Braun & Bouché) Brunken): weedy types, resulting from introgression between wild Pennisetum violaceum and cultivated Pennisetum glaucum and ranging in morphology between wild and cultivated types; in the latter case they are termed 'shibras' and they look much like Pennisetum glaucum cultivars, but differ in having deciduous shortly stiped involucres, and spikelets which shatter before harvest; bristles numerous, longer than spikelets; widespread in the Sahel and also found, though less frequently, in East and southern Africa. - Pennisetum violaceum (Lam.) Rich, ex Pers. (synonyms: Pennisetum fallax (Fig. & De Not.) Stapf & C.E.Hubb., Pennisetum americanum (L.) Leeke subsp. monodii (Maire) Brunken): wild, variable type, with deciduous sessile involucres which always contain a

128 130 CEREALS AND PULSES single spikelet; bristles numerous, longer than spikelets; distributed from the West African Sahel region to Eritrea in very dry locations, independent of farming; sometimes harvested as a wild cereal in times of scarcity. Although many intermediate cultivars occur, 4 cultivar groups (originally described as races) can be distinguished in cultivated Pennisetum glaucum, based mainly on grain shape and partly on distribution: - Typhoides Group; grain obovoid, circular in cross-section, mm x mm x1 2.5 mm, inflorescence cylindrical or ellipsoidal, usually less than 0.5 m long; it is the most primitive, the most variable and most widely distributed group, occurring all over the pearl millet range in Africa and India, and is probably ancestral for the other groups. - Globosum Group: grain globose, more than 2.5 mm in diameter, inflorescence cylindrical, often longer than 1 m; most common in the Sahel region west of Nigeria. - Leonis Group: grain oblanceolate in outline, circular in cross-section, mm x mm x mm, apex acute, inflorescence cylindrical; this is the smallest group and is grown in Mauritania, Senegal and Sierra Leone. - Nigritarum Group; grain obovoid but angular in cross-section, 3-5 mm x mm x mm, inflorescence cylindrical; most common in semi-arid regions from Nigeria to Sudan. Agronomically two main groups of cultivars are recognized in West Africa, based on growth duration : short-duration Gero (or Souna) cultivars and long-duration Maiwa (or Sanio) cultivars. Gero cultivars are less photoperiodsensitive, are more widely grown and exhibit more genetic diversity than Maiwa cultivars, in which flowering date is strongly controlled by daylength. Maiwa types are grown in regions where the rainy season is longer and where sorghum is the major cereal, but on poorer, more drought-prone soils. Certain Maiwa millets are transplanted from nurseries into the field and are known as Dauro millet. The improved cultivars and dwarf single-cross hybrids grown in India are stronger tillering, early (80 days) to very early (65 days) maturing and less photoperiod-sensitive than African cultivars. Growth and development Pearl millet cultivars vary in time to maturity from days, but mostly from days. Time to flower initiation is the main factor determining the life cycle of a cultivar. Floral initiation is weakly to strongly controlled by photoperiod, with short days accelerating flower initiation. Photoperiod response allows crop cycle length to be adjusted by time of planting, needed when rains begin late, to ensure that flowering and grain production occur at the same optimum time each year for a specific latitude. In short-duration, photoperiod-insensitive cultivars the developmental stages (from germination to flower initiation, to flowering and to maturity) areof approximately equal duration. Field establishment of pearl millet is affected by its relatively small seed size, especially in crusting soils. Other factors that influence stand establishment include high soil surface temperatures at emergence (as high as C), sand storms and early season moisture stress. During early development the roots grow more than the above-ground parts. Pearl millet produces an extensive and dense root system, which may reach a depth of m, exceptionally 3.5 m. Basal tillering occurs 2-6 weeks after sowing, and when planted in widely spaced pockets up to 40 tillers may be produced, especially on long-season cultivars. Secondary tillering from the upper nodes of stems is a common response to drought, or to damage to the stem or inflorescence. These aerial tillers produce 2-3 leaves and a small inflorescence within days; they may contribute 15% and occasionally up to 50%of grain yield. It takes days from inflorescence differentiation to flowering. Pearl millet has a protogynous breeding system, which encourages but does not enforce cross-pollination; 10% or more inbreeding may occur, depending on overlap in flowering between florets within an inflorescence and among tillers. Pearl millet cultivars are therefore heterogeneous and heterozygous random mating populations, which exhibit substantial inbreeding depression. Heavy rainfall, low temperature and moisture stress reduce seed set. The grain-filling period normally takes days. The harvest index of landraces is low ( ), attaining 0.35 in improved cultivars, and up to 0.45 in dwarf hybrids. Pearl millet is characterized by the C4 photosynthetic pathway. Vesicular-arbuscular mycorrhizae (e.g. Gigaspora and Glomus spp.) and nitrogen-fixing bacteria (e.g. Azospirillium spp.) are commonly found associated with pearl millet roots, which may assist with the uptake

129 PENNISETUM 131 of water, N and P. Ecology In West Africa, from the oases of the Sahara desert (under irrigation) to the northern Sahel (characterized by 250 mm annual rainfall), pearl millet cultivars are grown that are photoperiod insensitive and mature in days. In the mm rainfall zone, where very high temperatures are common, especially at planting time, it is the dominant cereal. The optimum temperature for germination of pearl millet seeds is C; no germination occurs below 12 C C. The optimum temperature for tiller production and development is C, and for spikelet initiation and development about 25 C. Extreme high temperatures before anthesis reduce pollen viability, panicle size and spikelet density, thus reducing yield. Pearl millet is tolerant of various soil conditions, especially of light and acid soils. Its large and dense root system allows it to grow on soils with a low nutrient status. Pearl millet does not tolerate waterlogging. Once established, the crop is fairly tolerant of salinity. Propagation and planting Propagation of pearl millet is by seed, usually sown directly in the field. Transplanting is carried out on a very limited scale in India and West Africa (Dauro millet). The 1000-seed weight is g. In Africa short-duration cultivars are sown early, after the first 20 mm rain of the season and land preparation is limited to a light hoeing. Land preparation for long-duration cultivars, which are sown later, is done more thoroughly. Pearl millet is usually sown directly in pockets (hills) in rows at plant distances of 45 cm x 45 cm to 200 cm x 200 cm depending on the cropping system (intercrop or sole crop). The pockets are opened with a hoe or a stick, a pinch of seeds is thrown in, and the hole is covered by soil using the foot. At the first weeding the crop is thinned to 2 or 3 plants per pocket. Farmers tend to adjust plant density based on average rainfall and soil fertility; it generally ranges from 20,000-50,000 plants per ha in pure stands. Seed rates vary accordingly from 2-5 kg per ha. Pearl millet is often intercropped with one to several crops, including cowpea, sorghum and groundnut. Management Pearl millet frequently needs 2 3 weedings, which are done mostly by hand. With short-duration cultivars in Africa, weeding coincides with land preparation and planting of later crops. Manual weeding places severe demands on available labour and limits the area that can be managed properly. In a few regions animal-drawn implements are used for weeding. Pearl millet is highly responsive to increased soil fertility, but under traditional rainfed farming conditions the application of manure and chemical fertilizers is limited. Because of the depleted fertility status of most pearl millet soils some phosphorus and potassium is needed for an optimal response to nitrogenous fertilizers. As fertilizers increase water use of the crop, plant populations and average seasonal water availability also need to be considered when making fertilizer recommendations. A pearl millet crop yielding about 3.1 t grain per ha in the West African savanna was recorded as removing 132 kg N, 28 kg P, 65 kg K and 31 kg Ca per ha from the soil. Diseases and pests Green ear caused by downy mildew (Sclerospora graminicola), grain smut (Tolyposporium penicillariae), rust (Puccinia substriata var. penicillariae) and ergot (Claviceps fusiformis) are important diseases of pearl millet, both in Africa and in Asia. Sources of resistance against all four have been identified and are being incorporated into new cultivars, except for resistance to ergot which is polygenic and recessively inherited. Birds are the major pest in pearl millet, especially Quelea spp. Bird scaring for several weeks before the harvest is essential. Farmers in West Africa often do not harvest a larger area than they can protect from birds. Cultivars with long, hard bristles are less vulnerable than those without. Stem borer (Coniesta ignefusalis), millet head miner (Heliocheilus albipunctella) and millet midge (Geromyia penniseti) are locally important. Other pests are white grubs, grasshoppers, locusts, and various Lepidoptera. Pearl millet is sometimes seriously attacked by adapted strains of the root parasite Striga hermonthica (Delile) Benth. in West Africa. Harvesting Pearl millet is harvested by hand, either by picking the panicles or by harvesting whole plants. In cultivars where tillers ripen unevenly, several pickings are required. Cultivars with long panicles are favoured for ease of harvest, bundling and transport. Yield Grain yields range from 250 kg/ha in the driest areas to kg/ha in the main production areas. Average yields in Africa and India are about 670 and 790 kg/ha, respectively. Under optimal conditions hybrids may reach grain yields of 5 t per ha in 85 days and yields of 8 t per ha have even been obtained. In landraces the above-ground dry matter yield may be 3 10 t/ha. In hybrids bred specifically

130 132 CEREALS AND PULSES for forage dry matter yields in a season range from t/ha. Handling after harvest A harvested pearl millet crop is dried in the sun for a few days. In Africa whole panicles are commonly stored in elevated granaries, built of mud or plant materials and covered with thatch. Sometimes they are stored in pits. Ash or neem (Azadirachta indica A.Juss.) leaves may be put in layers to reduce insect attack. Threshing is normally done manually when grain is needed. If dry and protected from insects, seed can be stored adequately at room temperature for several years. Pearl millet flour, unless dry-milled and well-packed, has poor storage quality because of rancidity due to the high oil content. Genetic resources Landraces of pearl millet have evolved over thousands of years through natural and human selection. Selection at different latitudes and in different agroclimatic zones for crop duration, yield, adaptability to nutrient-poor soils, resistance to drought and diseases, and grain type has resulted in local cultivars with a large range of morphological diversity and photoperiod sensitivity. Continual introgression with wild and weedy relatives in West Africa has further contributed to the crop's genetic diversity. Genetic variation is conserved and evaluated at the Coastal Plains Experiment Station, Tifton (Georgia, United States) and the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Hyderabad (India), where the world collection of over 24,000 entries is housed. The International Plant Genetic Resources Institute (IPGRI) supports a programme, started in Burkina Faso, to improve the description and evaluation of material at the time and location of collection. One particular germplasm source, the Tniadi' cultivar from northern Togo and Ghana, has had a profound effect on pearl millet breeding. Selections from it have been successful as cultivars in northern India, Namibia and Botswana, and it has been extensively used in all breeding programmes. Breeding Both improved open-pollinated types and hybrids have been developed in pearl millet ; cytoplasmic male sterility is available for the commercial production of hybrid seed. Cultivar breeding of pearl millet started in Africa in the 1950s and traditional cultivars are still widely used. Breeding work by the Indian Council of Agricultural Research and ICRISAT has been most successful in developing cultivars that were rapidly adopted by farmers. The discovery of cytoplasmic male sterility in 1958 in the forage breeding programme at Tifton (Georgia, United States) led to the production of early-maturing, semi-dwarf grain hybrids in India, which covered 3 million ha by Despite the occurrence of disease epidemics, some 50% of the Indian pearl millet crop on family farms now consists of hybrids and improved cultivars, and yields have increased by 40% since Early breeding work in West Africa by the Institut de Recherches Agronomiques Tropicales et de Cultures Vivrières (IRAT) and the East African Agriculture and Forestry Research Organization (EAAFRO) produced improved local cultivars, but adoption was negligible. Since the early 1980s ICRISAT, working with a broader germplasm base and in conjunction with national agricultural research programmes in West, East and southern Africa, has produced better cultivars. In 8 countries in West Africa 24 cultivars (11 for the Sahel zone and 13 for the Sudan Zone) have been released and in East and southern Africa 19 new cultivars are available for 8 countries with adoption rates of up to 50% (Namibia, Zimbabwe). Work at ICRISAT is focused on the identification of stable stress tolerance, wide adaptability and high yield potential. Sources of tolerance of the major diseases have been identified and are being incorporated into new cultivars. Two further cytoplasmic male sterility systems (A4 and A5), which have superior attributes both for hybrid breeding and seed production, have been discovered. These allow access to different heterotic patterns and more rapid development of new hybrids, particularly topcross hybrids which are most suited to the higher disease pressures in Africa. On average, single-cross hybrids (male-sterile x inbred restorer) give about 20% more grain yield than open-pollinated cultivars of similar maturity. Topcross hybrids (male-sterile x open-pollinated cultivars) benefit from the adaptability and durable disease resistance of the open-pollinated type, and give 10 15% more yield. The pearl millet genome has now been well mapped, and marker-assisted selection is being used to improve downy mildew and rust resistance. Transgenic pearl millet plants with various marker genes have been obtained using particle bombardment. Forage breeding work, mainly in the United States, Australia, Brazil and southern Africa, has also produced pearl millet hybrids. Interspecific hybrids between pearl millet and ele-

131 PHASEOLUS 133 phant grass (Pennisetum purpureum) are available; these are vigorous, variable, triploid and sterile, but selections are easily vegetatively propagated and used as a persistent perennial forage by small farmers in South-East Asia, East and southern Africa and South America. In the United States dwarf plant stature and synchronous maturity of tillers, in addition to earliness and tolerance of diseases have been successfully incorporated into pearl millet to convert it to a new feed grain crop suitable for mechanical cultivation. Commercial production of grain pearl millet for poultry feed has commenced in Georgia (United States). Prospects Pearl millet has great potential because it has one of the highest rates of dry matter gain among the Ci-cycle cereals, a very flexible breeding system and a large amount of genetic variability in the primary gene pool yet to be used. The results of pearl millet breeding work in India, where gains from breeding have been 1-2% per year over the last 35 years, demonstrate what can be achieved in Africa. Half of the millet area in India is now planted to improved cultivars, including hybrids. Proven breeding techniques and wider use of genetic resources will continue to produce better cultivars. In Africa small and seasonably variable grain markets, lack of credit and bulk grain storage have constrained farmers from making the monetary investments which will increase production. However, the growing urban demand for pearl millet flour, and food products like couscous allow farmer cooperatives in Niger, Mali and Senegal to make contracts before planting directly with urban grain processors, for the supply of grain meeting given standards, including grain type and colour, milling quality, flavour and freedom from impurities. In Senegal the cultivar is also specified. This enables subsistence farmers to benefit from seed of improved cultivars, and from purchased inputs such as fertilizer. Better cultivars, produced by certified seed farmers, are being marketed in Namibia, Nigeria and Senegal. Many production technologies have been researched and tested both for family farmers and largerscale pearl millet cultivation, including improved cultivars, better crop management, soil improvement and moisture conservation techniques for the major pearl millet producing regions in Africa. If reliable grain markets are established, pearl millet production in Africa can follow the example of India, and increase substantially on existing land. Major references Anand Kumar & Andrews, 1993; Andrews & Bramel-Cox, 1993; Andrews & Kumar, 1992; Bidinger & Hash, 2004; Brunken, de Wet & Harlan, 1977; Dendy (Editor), 1995; Khairwal et al., 1999; Oyen & Andrews, 1996; Pearson (Editor), 1985; Renard & Anand Kumar, Other references Andrews & Anand Kumar, 1996; Bationo et al., 1992; Bezançon, Renno & Anand Kumar, 1997; Bonamigo, 1999; Burkill, 1994; Clayton, 1989; Clayton & Renvoize, 1982; de Wet, 1995d; FAO, 1970; 2001; Hash, Schaffert & Peacock, 2002; Jagdale et al., 2000; Leung, Busson & Jardin, 1968; McDonough, Rooney & Serna-Saldivar, 2000; Monyo, 2002; National Research Council, 1996; O'Kennedy, Burger & Botha, 2004; Rachie & Majmudar, 1980; Rai et al., 2001; Stoop, 1986; Wilson, Sources of illustration Oyen & Andrews, Authors D.J. Andrews & K.A. Kumar Based on PROSEA 10: Cereals. PHASEOLUSACUTIFOLIUS A.Gray Protologue PI. wright. 1: 43 (1852). Family Papilionaceae (Leguminosae - Papilionaceae, Fabaceae) Chromosome number 2n = 22 Vernacular names Tepary bean, Texas bean (En). Haricot tépari, tépari (Fr). Feijäo tepari (Po). Origin and geographic distribution Tepary bean is an ancient crop of the south-western United States and northern Mexico. Recent Phaseolus acutifolius -planted

132 134 CEREALS AND PULSES studies indicate that the earliest remains of domesticated tepary bean, found in Tehuacân Valley, Mexico, date from around 2300 years ago. Isozyme analysis suggests that domestication took place in a single geographic region, with the Mexican states of Jalisco and Sinaloa being potential candidates. Today, wild types are distributed from the south-western United States (Arizona, New Mexico, Texas) to Guatemala, with the core of their distribution in north-western Mexico. Tepary bean is also cultivated in the southern United States and Central America. Cultivation of tepary bean decreased strongly after World War II, but nowadays the crop is regaining interest. Tepary bean has been introduced and is cultivated in Africa, Asia and Australia. It was introduced into francophone West Africa, Central Africa, East Africa and Madagascar between the first and second World Wars, and is now grown there and as far south as Botswana. Tepary bean is also recorded as being grown in Morocco, Algeria, South Africa, Swaziland and Lesotho. Uses Tepary bean is mainly grown for its mature dry seeds, which are eaten after boiling, steaming, frying or baking. They are used in stews and soups, and mixed with wholegrain maize. In Uganda the dry seeds are usually boiled and then coarsely ground before being added to soup. Occasionally it is eaten as a green bean or as bean sprouts. The leaves are considered edible in Malawi, but are tougher than those of common bean (Phaseolus vulgaris L.) and take longer to cook. Pods and stems remaining after removing the seed may be used for animal feed. In Botswana the seeds are a common supplementary feed for chickens. Tepary bean has occasionally been grown for fodder or green manure, e.g. in the United States. It may be used as a cover crop and an intercrop in agroforestry systems. Production and international trade Tepary bean is mainly grown in Mexico and Arizona (United States). Large-scale commercial production was tried in the early 1900s, but efforts were abandoned due to its unfavourable morphological characteristics compared to the common bean, changes in eating habits and lack of information on its performance. Tepary bean has recently gained importance in semiarid parts of tropical Africa, e.g. in Sudan, north-eastern Kenya, Uganda and Botswana, where most other grain legumes fail due to drought and where short-duration crops are often needed. Production is mainly for domestic consumption, and no production and trade statistics are available. Properties Per 100 g edible portion the composition of dry tepary bean seeds is: water 8.6 g, energy 1478 kj (353 kcal), protein 19.3 g, fat 1.2 g, carbohydrate 67.8 g, fibre 4.8 g, Ca 112 mg, P 310 mg, thiamin 0.33 mg, riboflavin 0.12 mg, niacin 2.8 mg and ascorbic acid 0 mg (Leung, Busson & Jardin, 1968). As with other pulses, the seeds are low in the sulphurcontaining amino acids methionine and cystine ( % and % of total amino acids, respectively). With respect to antinutritional factors, such as trypsin inhibitors, flatulent oligosaccharides and phytic acid, tepary bean is similar to cowpea and chickpea; the lectin activity is exceptionally high, but is readily reduced by cooking, whereas cyanogenic glucosides have not been detected. Consumption of raw tepary bean flour has been recorded to cause death in mice and rats within 3 4 days, but soaking and cooking the seeds eliminated toxicity completely. Tepary beans have a strong flavour and odour and are less palatable than common beans. On storage the dry seeds become very hard and take a long time to cook. Cultivars with white seeds have a more permeable seedcoat than cultivars with black seeds, resulting in a shorter cooking time. Tepary bean hay contains 6.6% water, 9.9% protein, 1.9% fat, 43.1% N-free extract, 29.3% fibre, and 9.2% ash. Pods and stems contain 8% water, 4.1% proteins, 0.5% fat, 43.6% N-free extract, 37.0% fibre and 6.8% ash. Description Climbing, trailing or more or less erect and bushy annual herb, with stems up to 4 m long; roots fibrous. Leaves alternate, 3-foliolate; stipules lanceolate, 2-3 mm long, appressed to stem; petiole 2-10 cm long; stipels linear, up to 2 mm long; leaflets ovate to ovatelanceolate, 4-8 cm x 2-5 cm, acute, usually pubescent below. Inflorescence an axillary raceme, 2-5 flowered. Flowers bisexual, papilionaceous; pedicel 3 7 mm long; calyx campanulate, 3 4 mm long, the upper 2 lobes united into one, the lower 3 triangular; corolla white, pink or pale lilac, standard halfreflexed, broad, emarginate, up to 1 cm long, wings up to 1.5 cm long, keel narrow, coiled; stamens 10, 9 fused and 1 free; ovary superior, c. 0.5 cm long, densely pubescent, style with a thickened terminal coil, with collar of hairs below the stigma. Fruit a compressed pod, straight or slightly curved, 5 9 cm x cm, rimmed on margins, with short but distinct beak, hairy when young, 2-9-seeded. Seeds

133 PHASEOLUS 135 Phaseolus acutifolius - 1, flowering branch with young fruit; 2, fruits; 3, seeds. Source: PROSEA globose to oblong, 4-7(-10) mm x 2-5(-7.5) mm, white, yellow, brown, purple, black or variously speckled, dull. Seedling with epigeal germination; first pair of leaves simple. Other botanical information Phaseolus comprises about 50 species, most of them in the Americas. Three varieties of Phaseolus acutifolius have been distinguished, based on the shape of leaflet and seeds. Var. acutifolius and var. tenuifolius A.Gray comprise wild types from south-western United States and northwestern Mexico, whereas var. latifolius G.F. Freeman comprises wild and cultivated types. Isozyme and AFPL analyses have shown no clear-cut differentiation between var. acutifolius and var. tenuifolius. Growth and development Tepary bean seeds absorb water easily; in moist soils the testa wrinkles within 5 minutes, in water in 3 minutes. This leads to quick germination. Seedling emergence is faster in white-seeded than in dark-seeded types. The seeds of domesticated types have no dormancy, which is a disadvantage in humid regions, where fallen seeds will germinate rapidly. The rate of germination increases with increasing temperatures from 10 C to 35 C. Flowering occurs within days. Self-pollination occurs before anthesis. In the tropics, short-duration types may mature within 2 months, but most types have a growth period of days. In cooler regions, such as coastal Algeria, the growth period averages 120 days. The seeds of many domesticated types of tepary bean are shattered less easily than those of wild types. Tepary bean shows effective nodulation and nitrogen fixation only with Bradyrhizobium isolates. Hybrids of tepary bean and common bean (the latter nodulating with Bradyrhizobium but only fixing atmospheric nitrogen when nodulated with Rhizobium leguminosarum bv. phaseoli) can be divided in 2 groups: one group only fixing nitrogen with Bradyrhizobium, the other only with Rhizobium leguminosarum bv. phaseoli. Ecology Tepary bean is particularly suited to arid regions as it is tolerant of drought, heat and a dry atmosphere. Factors contributing to the drought tolerance of tepary bean are sensitive stomata, closing already at relatively high water potentials, and a deep and extensive root system. Tepary bean is found in regions with a mean annual temperature of C; the minimum night temperature should not drop below 8 C. It can grow in areas with an annual rainfall ranging from mm, but where annual rainfall exceeds 1000 mm, vegetative growth is usually excessive, at the expense of seed yield. After flowering little or no rain is needed. In most of Africa, tepary bean is grown as a short-season crop, but in the more humid parts it is grown year-round. In Mexico and Arizona, it is usually grown at medium altitudes. Some tepary bean types require short days for flowering, but others seem day-neutral. Light, well-drained soils are preferred; reasonable yields can be obtained on poor sandy soils with ph 5-7. Tepary bean does not tolerate waterlogging, and heavy clays are unsuitable. It is moderately tolerant of saline and alkaline soils. The salt tolerance may not be physiological but result from its ability to escape salinity due to its root system going deeper than that of e.g. common bean. Propagation and planting Tepary bean is propagated by seed. The 1000-seed weight is g for cultivated and g for wild genotypes. Seeds are broadcast at a rate of kg/ha, or drilled in rows cm apart with cm between plants within the row. The sowing depth is cm. Tepary bean is sometimes sown on mounds, with 2-4 seeds per mound. In Kenya tepary bean is sown at

134 136 CEREALS AND PULSES kg/ha in a spacing of 60 cm x 30 cm. When grown for hay, seed rates are about 70 kg/ha. Tepary bean is grown as a sole crop or intercropped with cereals (sorghum, millet, maize), vegetables (Allium, Brassica, Capsicum, Cucurbita spp.), or other pulses. In the United States and Mexico tepary bean is sometimes sown in unsorted admixtures with common bean, thus providing greater yield stability than common bean alone and higher potential yields than tepary bean alone. Management Weeding of tepary bean is essential, particularly during early growth. It requires little weeding, however, when it is grown as an 'end-of-season' crop. Little is known about its nutrient requirements, and its response to nitrogen and potassium fertilizers is not consistent. Irrigation may be applied, but is not usual. In intercropping the cultural practices for the main crop are applied to tepary bean. In Senegal and Mali tepary bean is grown as a kitchen garden vegetable. Diseases and pests Tepary bean is generally not affected by diseases in semi-arid regions, except during periods when humidity is high. Within the species, variable levels of resistance exist against common bacterial (bean) blight (Xanthomonas campestris pv. phaseoli), bean rust (Uromyces appendiculatus), Fusarium rot (Fusarium sp.), powdery mildew (Erysiphe polygoni), anthracnose (Colletotrichum lindemuthianum), angular leaf spot (Phaeoisariopsis griseola) and charcoal rot (Macrophomina phaseolina). Tepary bean is susceptible to white mould disease (Sclerotinia sclerotiorum) and also considered susceptible to halo blight (Pseudomonas syringae pv. phaseolicola); it is listed as a host of southern blight (Sclerotium rolfsii) and Pythium rot (Pythium aphanidermatum). Tepary bean is highly susceptible to bean common mosaic virus (BCMV), and also has shown susceptibility to alfalfa mosaic virus (AMY), bean yellow mosaic virus (BYMV), beet curly top virus (BCTV), bean pod mottle virus (BPMV) and bean golden mosaic virus (BGMV). Leafhoppers (Empoasca kraemeri) and pod borers (Epinotia opposita) were found in waterstressed trials. Several lines have shown resistance against the former, but the mechanism was non-preference rather than antibiosis. The Mexican bean beetle (Epilachna varivestis) and the potato leafhopper (Empoasca fabae) have been found to cause damage to tepary bean. Some resistance to the black bean aphid (Aphis fabae) and the lesser corn stalk borer (Elasmopalpus lignosellus) has been observed. The hard seed coat makes the seed resistant to storage pests such as bruchid beetles (Callosobruchus and Acanthoscelides spp.). In Uganda, however, the rice weevil (Sitophilus oryzae) has been recorded in stored seed. Harvesting Pods on the same tepary bean plant do not usually mature simultaneously, and as pods may shatter if left to dry up in the field, they are normally harvested by hand as soon as they change colour, usually months after planting. Sometimes whole plants are pulled up by hand. Normally the pods are dried for a few days before they are threshed. In Africa beating the dried pods or plants with sticks is common practice to thresh tepary bean. Yield In Uganda average yields of tepary bean are kg dry seeds per ha. In dryland farming in the United States yields are kg/ha, under irrigation kg/ha. When grown for fodder, ,000 kg/ha oven-dry hay can be obtained. Handling after harvest Unlike most other pulses, tepary bean seed stores well and it hardly needs storage pest control. Genetic resources The genetic basis of cultivated tepary bean is narrower than that of cultivated common bean and Lima bean (Phaseolus lunatus L.), and most genetic diversity for future improvement resides in the wild types. Collection of germplasm from the native area of tepary bean is recommended. Wild tepary bean genepools have decreased due to habitat elimination and degradation, whereas domesticated tepary bean has suffered genetic erosion due to its shrinking area of cultivation. Exchange of genetic information between common bean and tepary bean is possible, but only for the transfer of simple traits involving only a few genes. Although common bean and tepary bean have the same chromosome number and similar karyotypes their mitochondrial genomes, agroecological adaptations and morphological characters are distinct, indicating that they are fairly divergent species. The largest germplasm collection of tepary bean (about 350 accessions) is held at CIAT (Centro Internacional de Agricultura Tropical) in Cali, Colombia. Another large collection is present at the USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, United States (211 accessions). Smaller collections are held in Australia (Australian Tropical Crops & Forages Genetic Resources

135 PHASEOLUS 137 Centre, Biloela; 70 accessions), Belgium (National Botanical Garden of Belgium, Meise; 59 accessions), Mexico (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias (INIFAP), Col. San Rafael; 40 accessions) and Guatemala (Centro Universitario de Sur Occidente (CUNSUROC), Universidad de San Carlos, Mazatenango; 31 accessions). In Africa, 29 accessions are held at ISRA (Institut Sénégalais de Recherches Agricoles), Dakar, Senegal, and 10 accessions at ILRI (International Livestock Research Institute), Addis Ababa, Ethiopia. Most collections comprise wild as well as cultivated types. Breeding Tepary bean is generally resistant to diseases and pests, tolerant to drought, heat and salinity and has a short crop cycle. Prospects for selection are favourable, as sufficient variation in resistance to biotic and abiotic stress factors exists within the species. Except for some mass-selected populations, no improved tepary bean cultivars have been released to farmers. Rather, its favourable traits have mainly been targeted to improve common bean instead of tepary bean itself. Resistance to common bacterial (bean) blight, for instance, has been transferred into common bean through interspecific hybridization. In attempts to cross Phaseolus acutifolius with Phaseolus vulgaris, artificial cross-fertilization does not pose problems, but post-zygotic barriers usually prevent normal embryo development, and, as a rule, no viable hybrids are obtained. Embryo rescue through in-vitro culture is normally required to complete hybridization successfully. Through recurrent backcrossing with alternating parents the hybrids become cross-fertile with both species. However, genes obtained from common bean tend to be predominant in these hybrids. Seeds have also been obtained from a cross involving a Phaseolus acutifolius accession (NI 576) without invitro culture. Agrobacterium-mediated genetic transformation of this accession has been achieved, based on regeneration from callus. This has opened up the possibility of using Phaseolus acutifolius to introduce transgenes into the economically more important Phaseolus vulgaris. Prospects Tepary bean seems a very suitable crop for resource-poor farmers in Africa, since its rapid germination, deep root system and short life cycle make it well adapted for production in arid or semi-arid regions. Reasons for reluctance to adopt tepary bean as a food include the small seed size, the tendency to cause flatulence, the long cooking time, the laboriousness of the harvest, and its strong flavour and, according to some, objectionable odour. However, in northern Kenya and Nigeria, traditional dishes prepared with tepary bean instead of cowpea were found very acceptable. To promote tepary bean in Africa, the selection of high-yielding cultivars, the development of food products (protein supplements) with reduced odour, and the creation of a marketing infrastructure are a prerequisite. Major references CIAT, 2003; Dillen et al., 1997; Hornetz, 1993; Jansen, 1989d; Kaplan & Lynch, 1999; Kay, 1979; Miklas et al, 1994; National Academy of Sciences, 1979; Pratt & Nabhan, 1988; Tinsley et al., Other references Aganga et al., 2000; Baudoin & Maquet, 1999; Debouck & Smartt, 1995; Freytag & Debouck, 2002; Garvin & Weeden, 1994; Idouraine, Tinsley & Weber, 1989; Idouraine, Weber & Kohlhepp, 1995; Kaiser, 1981; Leung, Busson & Jardin, 1968; Lin & Markhart III, 1996; Markhart III, 1985; Mogotsi, 1982; Munoz et al, 2004; Nabhan & Felger, 1978; Purseglove, 1968; Schinkel & Gepts, 1988; Somasegaran, Hoben & Lewinson, 1991; Stanton, 1966; Thorn et al., 1983; White & Montes, Sources of illustration Jansen, 1989d. Authors K.K. Mogotsi PHASEOLUS COCCINEUS L. Protologue Sp. pl. 2: 724 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2/t = 22 Vernacular names Scarlet runner bean, runner bean, multiflora bean, case knife bean (En). Haricot d'espagne (Fr). Feijào da Espanha, feijäo escarlata, feijäo trepador (Po). Origin and geographic distribution Scarlet runner bean occurs wild from Mexico to Panama. It was probably domesticated in Mexico. Archaeological evidence indicates that scarlet runner bean was a domesticated crop in Mexico around 900 AD. Nowadays scarlet runner bean is cultivated in temperate countries and occasionally in highland areas of Central and South America, Africa (e.g. Ethiopia, Kenya, Uganda, South Africa) and Asia. It is probably cultivated in Madagascar and is recorded as being grown in the eastern part of tropical southern Africa, although no specific countries are mentioned.

136 138 CEREALS AND PULSES Phaseolus coccineus - planted Uses In Central America the immature and mature seeds are consumed, elsewhere mainly the mature seeds, e.g. in Ethiopia. Preparation is predominantly by boiling. In temperate regions the immature pods are most commonly eaten, sliced and cooked, as a vegetable. In Central America the young shoots, leaves and inflorescences are sometimes used (boiled or boiled and fried) as a vegetable while the tuberous roots are consumed boiled or chewed as candy. A root decoction is taken against malaria or applied to swollen eyes. In Central America scarlet runner bean is grazed by livestock and dried into hay. It is grown as an ornamental. Production and international trade Accurate production statistics for scarlet runner bean are not available. Production is almost exclusively for local use. Commercial production of the pods is done in the United Kingdom and Argentina and of the seeds of white-seeded cultivars in South Africa. In Kenya scarlet runner bean is mainly grown by smallholders. Properties Per 100 g edible portion the composition of dried scarlet runner bean seeds is: water 12.5 g, energy 1415 kj (338 kcal), protein 20.3 g, fat 1.8 g, carbohydrate 62.0 g, fibre 4.8 g, Ca 114 mg, P 354 mg, Fe 9.0 mg, thiamin 0.50 mg, riboflavin 0.19 mg, niacin 2.3 mg and ascorbic acid 2 mg (Leung, Busson & Jardin, 1968). The seeds contain antinutritional factors such as trypsin inhibitors, and must be cooked before being eaten to break down these compounds. Per 100 g edible portion, raw green pods (ends and sides trimmed) contain: water 91.2 g, energy 93 kj (22 kcal), protein 1.6 g, fat 0.4 g, carbohydrate 3.2 g, fibre 2.6 g, Ca 33 mg, Mg 19 mg, P 34 mg, Fe 1.2 mg, Zn 0.2 mg, carotene 145 ng, thiamin 0.06 mg, riboflavin 0.03 mg, niacin trace and ascorbic acid 18 mg (Holland, Unwin & Buss, 1991). Many improved cultivars have substantial reduction in the fibrous vascular strands of the pod sutures ('stringless runner beans'). The tuberous root of scarlet runner bean is edible, but it is fibrous and may contain toxic compounds, which can be removed by soaking or peeling and by discarding the cooking water. Coccinin, a peptide isolated from the seed of scarlet runner bean, has shown antifungal activity against a range of fungi. It also inhibited proliferation in leukaemia cell lines and reduced the activity of HIV-1 reverse transcriptase. Description Perennial, climbing herb with stems up to 4(-7) m long or bushy annual herb up to 60 cm tall; taproot tuberous. Leaves alternate, 3-foliolate; stipules triangular; petiole (6-) (-16) cm long, rachis (1.5-)2.5-4(- 5) cm long; stipels c. 5 mm long; leaflets ovaterhombic, (5-) (-12.5) cm x (3.5-)5-8.5(- 12.5) cm, base cuneate or truncate, apex acute, thinly pubescent to glabrescent. Inflorescence Phaseolus coccineus - branch; 2, fruit; 3, seed. Source: PROSEA 1, part of flowering

137 PHASEOLUS 139 an axillary or terminal raceme, many-flowered; peduncle (5-)ll-16.5(-25.5) cm long; rachis (2-) 10-16(-39.5) cm long. Flowers bisexual, papilionaceous; pedicel cm long; calyx campanulate, glabrescent, tube c. 3 mm long, the upper 2 lobes united, the lower 3 triangular, c. 1 mm long; corolla scarlet, pink or white, standard hood-shaped, circular or broadly obovate, c. 17 mm x 17 mm, wings broadly obovate, c. 25 mm x 17 mm, keel coiled, c. 10 mm long; stamens 10, 9 fused and 1 free; ovary superior, c. 6 mm long, finely pubescent, style coiled, with collar of hairs below the stigma. Fruit a linearlanceolate, straight or slightly curved pod (4.5-) 9-13(-30) cm x cm, laterally compressed, beaked, glabrescent, rough with small oblique ridges, (l-)3-5(-10)-seeded. Seeds ellipsoid-oblong, mm x 6-13(-16) mm, black, white, cream or brown, often pink to purple mottled. Seedling with hypogeal germination; first pair of leaves simple and opposite. Other botanical information Phaseolus comprises about 50 species, most of them in the Americas. Phaseolus coccineus is closely related to Phaseolus dumosus Macfad. (synonym: Phaseolus polyanthus Greenman; year-bean, sometimes also called runner bean) and Phaseolus costaricensis Freytag & Debouck. Hybrids between Phaseolus coccineus and these 2 species have been obtained; natural hybridization also occurs. The 3 species can be crossed with common bean (Phaseolus vulgaris L.), with the latter as female parent, without embryo rescue, although progenies may be partially sterile. Where scarlet runner bean and common bean grow together, natural hybridization may occur. Hybridization of scarlet runner bean with tepary bean (Phaseolus acutifolius A.Gray) is also possible. Phaseolus coccineus is a variable species, and levels of genetic variability are high, both in wild and in cultivated populations. A whiteseeded type of Phaseolus coccineus is known as 'butter bean' in Kenya and South Africa, but this name is normally applied to Phaseolus lunatus L. In Uganda, where the crop is grown a high altitudes in Nakuru District, whiteseeded cultivars are most common. Growth and development Scarlet runner bean seeds germinate days after sowing. Flowering starts days after sowing. Flowers open at sunrise and fade at sunset. Phaseolus coccineus is predominantly crosspollinating. Harvesting of green pods starts around 3 months after sowing and can be easily sustained for 2-3 months. Mature seed can be harvested 4-5 months after sowing. Bushy cultivars produce earlier and smaller crops than climbing cultivars. In Central America scarlet runner bean is sometimes grown as a perennial: where stems die back during cooler periods, the tuberous taproot remains viable and produces new stems with returning warmth. In temperate regions scarlet runner bean is grown as an annual. Scarlet runner bean fixes atmospheric nitrogen by symbiosis with fast-growing Rhizobium bacteria. Ecology Scarlet runner bean is a crop for temperate climates. In the tropics it is most successful at altitudes of m. In Kenya it is grown at m altitude, in Ethiopia up to about 2000 m. Scarlet runner bean is more tolerant of cool conditions than other Phaseolus species, but damage occurs at temperatures below 5 C. At temperatures above 25 C fruit development is inhibited. Scarlet runner bean is extremely susceptible to drought and requires a well-distributed rainfall throughout the growing period. In Ethiopia it is successfully grown in areas with an average annual rainfall of 1500 mm. It needs a high relative humidity for seed set. Scarlet runner bean comprises short-day and day-neutral types. Scarlet runner bean is adapted to a wide range of soils, but it prefers deep, well-drained, loamy, light- to medium-textured soils, with ph 6-7. Waterlogging is not tolerated. Propagation and planting Scarlet runner bean is normally propagated by seed, but the tuberous root with a piece of stem can also be used. The 1000-seed weight is g. The seedbed should be well prepared and weed free. Normal planting densities are 50,000-75,000 plants/ha for climbing types and double those for bushy types, requiring about 75 kg and 150 kg seed per ha, respectively. However, lower densities have also been recorded. In Mauritius scarlet runner bean is sown in rows 100 cm apart with 30 cm within the row. The sowing depth is cm. In Central America scarlet runner bean is often intercropped with maize. Management To obtain high-quality pods, scarlet runner bean is grown on trellises, poles, fence lines or other support structures. However, labour and material requirements are high and may impede cultivation. Climbing types can yield without support if leading shoots are pinched out to induce bushy growth. Scarlet runner bean should be kept weed-free during the early growth stages and it is commonly weeded once or twice. Tillage should be

138 140 CEREALS AND PULSES shallow to avoid root damage. Supplementary irrigation is beneficial. In Ethiopia scarlet runner bean is a garden crop. Diseases and pests In the tropics scarlet runner bean is affected by anthracnose (Colletotrichum lindemuthianum) and Fusarium wilt (Fusarium solani f.sp. phaseoli). The seedborne disease halo blight (Pseudomonas savastanoi pv. phaseolicola, synonym: Pseudomonas syringae pv. phaseolicola) has been isolated from scarlet runner bean in South Africa. Harvesting Green pods of scarlet runner bean are harvested when pod length reaches its maximum before the phase of rapid seed development. Picking is usually at 4 5 day intervals. For dry seed production, plants are pulled or cut when most pods are dry and then allowed to dry for a few days. Alternatively pods may be handpicked in several rounds because of asynchronous ripening. Yield Yields of green pods of 10 t/ha and of seeds of 1.5 t/ha are possible. The yield of dry mature seeds in Kenya has been estimated at kg/ha. Handling after harvest After drying, scarlet runner bean pods are threshed. Genetic resources In Brazil 428 accessions are maintained by EMBRAPA/CENARGEN in Brasilia. Large germplasm collections of scarlet runner bean are also maintained in the United States (USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, 478 accessions from throughout the world including Ethiopia and Kenya) and Mexico (Banco Nacional de Germoplasma Vegetal, Universidad Autónoma Chapingo, Chapingo, 311 accessions). In Africa 6 accessions are kept in South Africa (Division of Plant and Seed Control, Department of Agriculture, Pretoria) and 1 in Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa). Breeding Breeding efforts for scarlet runner bean have been directed to improvement of culinary quality (stringlessness) and disease resistance. Selection to improve cooking quality is promising since seed proteins of scarlet runner bean are more polymorphic than those of common bean. For dry seed production, improvement of plant habit and shorter pods are appropriate objectives of selection. Cultivars with a determinate growth habit suitable for mechanical harvesting CVenere' and 'Alarico') have been developed in Italy, by crossing Phaseolus coccineus with determinate Phaseolus vulgaris cultivars and repeated backcrossing with Phaseolus coccineus. Moderate levels of resistance to common bacterial blight (Xanthomonas campestris pv. phaseoli), Fusarium root rot (Fusarium solani f.sp. phaseoli) and white mould (Sclerotinia sclerotiorum) have been transferred from scarlet runner bean to common bean. Scarlet runner bean is also considered as a potential source of resistance against other diseases of common bean, including anthracnose, Ascochyta blight (Phoma exigua), angular leaf spot (Phaeoisariopsis griseola), powdery mildew (Erysiphe polygoni) and rust (Uromyces appendiculatus). Considerable tolerance to bean flies (Ophiomyia spp.) has been detected in scarlet runner bean, and tolerance has been transferred into common bean. On the other hand, resistance to halo blight has been transferred from common bean to scarlet runner bean. In vitro plant regeneration of scarlet runner bean is possible using cotyledons, through direct organogenesis as well as somatic embryogenesis via callus. Prospects Scarlet runner bean is a suitable pulse and vegetable crop for the humid highland tropics, although the need to provide support and the uneven maturation of the pods are serious drawbacks for commercial production. Scarlet runner bean may have some potential at higher altitudes in tropical Africa, but more information is needed on appropriate sowing and management practices. It is a potential source of resistance to diseases and pests affecting common bean. Major references Campion, 1995; Debouck & Smartt, 1995; Freytag & Debouck, 2002; Gepts (Editor), 1988; Kay, 1979; Singh, 2001; Smartt, 1989a; Suttie, 1969; Webster, Ross & Sigourney, 1980; Westphal, Other references Duke, 1981; du Puy et al., 2002; Escalante et al, 1994; FAO, 1989; Fourie, 1998; Hidalgo & Beebe, 1997; Holland, Unwin & Buss, 1991; Kaplan & Lynch, 1999; Knudsen (Editor), 2000; Leung, Busson & Jardin, 1968; Liebenberg, 1995; Mahuku et al., 2002a; Mahuku et al., 2002b; Nagl, Ignacimuthu & Becker, 1997; Ngai & Ng, 2004; Schmit & Baudoin, 1992; Smartt, 1976; Summerfield & Roberts (Editors), 1985; Thulin, 1989a; Yu, Stall & Vallejos, Sources of illustration Smartt, 1989a. Authors M. Brink Based on PROSEA 1: Pulses.

139 PHASEOLUS 141 PHASEOLUS LUNATUS L. Protologue Sp. pi. 2: 724 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2re = 22 Vernacular names Lima bean, butter bean, Madagascar bean (En). Haricot de Lima, pois du Cap, pois souche, pois savon (Fr). Feijào de Lima, feijào favona, feijâo espadinho (Po). Mfiwi (Sw). Origin and geographic distribution Lima bean has a Neotropical origin with at least two centres of domestication: Central America (Mexico, Guatemala) for the small-seeded types and South America (mainly Peru) for the largeseeded types. This distinction coincides with a classification into 2 types (Mesoamerican and Andean) on the basis of morphological, ecological, protein and molecular characters. Wild and cultivated forms of the same race are grouped together. The Andean wild populations have a very limited geographic distribution (Ecuador and northern Peru). The Mesoamerican wild types extend from Mexico to Argentina through the east side of the Andes. Recent discoveries have led to the proposition of 3 primary centres of genetic diversity, 2 of which are also domestication centres: a centre of genetic diversity and domestication on the western slope of the Andes in southern Ecuador and northern Peru; a centre of genetic diversity and domestication in Central America; and a centre of genetic diversity in the region covering northern Peru, northern Colombia, northern Ecuador and western Venezuela. In post-columbian times, Lima bean spread throughout the Americas. Spaniards took seeds Phaseolus lunatus - planted across the Pacific to the Philippines and from there it spread to other parts of Asia, mainly Java and Myanmar (Burma), and to Mauritius. The slave trade introduced Lima bean from Brazil into Africa, particularly to the western and central parts. Some large-seeded types from the Peruvian coast were distributed to south-western Madagascar and southern California. Lima bean is now cultivated throughout tropical Africa and the rest of the tropics, and has frequently become naturalized. Uses Lima bean is cultivated primarily for its immature and dry seeds, which in tropical Africa are usually eaten boiled, fried in oil or baked. In Nigeria they are also cooked with maize, rice or yam and used in making special kinds of soup and stew. The Yoruba people process the seeds into porridges, puddings and cakes. Immature green seeds, young pods and leaves are eaten as a vegetable, e.g. in Ghana and Malawi. In the United States, fresh and dry Lima beans are processed on an industrial scale involving canning and freezing. Sprouts and young plants are cooked and eaten in many Asian countries. The seeds are sometimes used as fodder, but may lead to hydrogen cyanide poisoning when used raw. The leaves and stems may be turned into hay or silage. Juice from the leaves is used in nasal instillations against headache and as eardrops against otitis in Senegal and DR Congo. In Nigeria the seeds are powdered and rubbed into small cuts on tumours and abscesses to promote suppuration. In traditional Asian medicine the seeds and leaves are valued for their astringent qualities and used as a diet against fever. Lima bean has been grown as a cover crop and for green manure. Production and international trade Production statistics for Lima bean from many tropical regions are fragmentary and often aggregated with other pulses. The United States is the largest producer of Lima bean with about 21,000 ha under cultivation (mainly in California, Delaware, Maryland and Wisconsin) and a production of (primarily fresh) beans of about 70,000 t in Madagascar is the second largest commercial producer with an area cropped varying from 3000 to 19,000 ha (mainly in the flood plains of the semi-arid coastal region in the south-western part) and a production of dry seed of about 8000 t, almost exclusively of large white-seeded types. Peru comes third with a production of dry seed of t from ha. In other countries, Lima beans are grown mostly in gardens

140 142 CEREALS AND PULSES or as an intercrop, but there are no estimates of area or production. In Africa the area planted with Lima bean in the sub-humid and humid tropics (especially Sierra Leone, Liberia, Côte d'ivoire, Ghana, Nigeria and DR Congo) has been estimated for the 1980s as 120, ,000 ha, with a total annual production of 50, ,000 t. No trade statistics are available. Properties The composition of dried raw seeds per 100 g edible portion is: water 11.6 g, energy 1214 kj (290 kcal), protein 19.1 g, fat 1.7 g, carbohydrate 52.9 g, dietary fibre 19.4 g, Ca 85 mg, Mg 190 mg, P 320 mg, Fe 5.9 mg, Zn 2.8 mg, carotene trace, thiamin 0.45 mg, riboflavin 0.13 mg, niacin 2.5 mg, vitamin B mg and ascorbic acid trace (Holland, Unwin & Buss, 1991). The essential amino-acid composition per 100 g raw Lima beans is: tryptophan 180 mg, lysine 1440 mg, methionine 280 mg, phenylalanine 1160 mg, threonine 800 mg, valine 980 mg, leucine 1560 mg and isoleucine 950 mg (Paul, Southgate & Russell, 1980). As in other pulses, the main limiting amino acids are methionine and cystine. Antimetabolic factors include protease inhibitors, lectins and cyanogenic glucosides (linamarin or phaseolunatin). The latter are accompanied by an enzyme, linamarase, which can hydrolyze the glucosides into a sugar and an aglycone, which in turn is split into acetone and hydrogen cyanide (HCN). Hydrolysis occurs rapidly when the soaked seeds are cooked in water; most of the HCN then evaporates. Linamarin and linamarase are heat-sensitive but inactivated at different temperatures: 140 C for the glucoside and 80 C for the enzyme. If inactivation of the enzymes takes place before complete hydrolysis, the residual glucoside may break down in the human organism under the influence of enzymes secreted by the intestinal microflora, leading to poisoning. The HCN content is significantly higher in wild types ( ppm) than in cultivated ones ( ppm). Soaking Lima bean seeds in water overnight easily eliminates the apparent toxicity, which is explained by the release of HCN during the process. In Nigeria, cooking time for dry seeds is hours. In Malawi, cooking times have been recorded of hours for dry, unsoaked seeds and hours for dry, soaked seeds. Per 100 g edible portion, green pods contain 1.3 g protein, and green leaves 0.6 g. Immature Lima bean seeds contain per 100 g edible portion: water 66.3 g, protein 8.3 g, fat 0.7 g, carbohydrate 23.1 g, fibre 1.0 g, Ca 28 mg, P 111 mg, Fe 2.6 mg, vitamin A 65 IU, thiamin 0.15 mg, riboflavin 0.10 mg, niacin 1.20 mg and ascorbic acid 27.0 mg (Kay, 1979). Lima bean silage contains 27.3% dry matter, 3.3% protein, 2.1% digestible protein and 14.2% digestible nutrients. Description Climbing, trailing or more or less bushy annual or perennial herb, with glabrous or pubescent stems up to 4.5(-8) m long; roots thin or swollen, up to 2 m deep. Leaves alternate, 3-foliolate; stipules ovate to lanceolate, 2-4 mm long; petiole cm long, rachis 0.5-5(-8) cm long; stipels 1-2 mm long; leaflets ovate, cm x 1-11 cm, acute or acuminate, sparsely pubescent or glabrous. Inflorescence an axillary raceme or panicle up to 15( 40) cm long, with many nodes, fewflowered to many-flowered. Flowers bisexual, papilionaceous; pedicel 5-10 mm long; calyx campanulate, mm long, puberulous, the upper 2 lobes united, the lower 3 broadly triangular; corolla 7-10 mm wide, standard hoodshaped, 5-7 mm x 5-10 mm, white, pale green or rose-violet, wings spatulate to obovate, 7 10 mm long, white or violet, keel sharply up Phaseolus lunatus - 1, flowering and fruiting branches; 2, flower; 3, seeds. Source: PROSEA

141 PHASEOLUS 143 turned, white or pale green; stamens 10, 9 fused and 1 free; ovary superior, c. 3 mm long, minutely hairy, style with a terminal coil, with collar of hairs below the stigma. Fruit an oblong pod (4.5-)5-10.5(-13) cm x l-2(-3) cm, compressed, generally curved, beaked, glabrous or pubescent, 2-4(-5)-seeded. Seeds kidneyshaped to rhomboid or globose, 8-11 mm x 6-7 mm, white, green, yellow, brown, red, purple, black or variously speckled, often with transverse lines radiating from the hilum. Seedling with epigeal germination; first pair of leaves simple and opposite. Other botanical information Phaseolus comprises about 50 species, most of them in the Americas. Wild and cultivated types of Phaseolus lunatus have been distinguished as var. Silvester Baudet and var. lunatus, respectively. Within the cultivated types some cultivar groups have been distinguished: Sieva Group with medium-sized flat seeds, Potato Group with small globular seeds, and Big Lima Group with large flat seeds. Wild types from the Andes appear closest to the cultivated types. In Malawi types of Lima bean are distinguished and named according to the size and shape of the seeds, e.g. 'mayemba' (large white or black speckled seeds, slightly bitter, seed coats moderately tough), 'butter' or 'Madagascar' (large flat white seeds, with a good flavour, seed coats soft and tasteless), 'moki' (small, white, flat seeds, good flavour, seed coats moderately tough), and 'pebugale' (seed shape variable, colour pale pink, speckled red, slightly bitter with tough seed coats). Growth and development Germination of Lima bean seeds occurs 4 10 days after sowing. Vegetative growth accelerates after one month. Flowers appear days and ripe pods days after sowing with short daylength. Cultivated Lima bean has two distinct growth habits: an indeterminate growth habit (prostrate or climbing; with axillary flowering only) and a pseudo-determinate growth habit (dwarf or bush plants; with terminal and axillary flowering). The vegetative cycle of pseudo-determinate growth types is shorter than that of indeterminate ones. The earliest bush cultivars mature within 90 days whereas the climbing types require 6 9 months. In climbing types, flowering and fruiting may extend throughout the wet season. The growth habit of perennial wild types is always indeterminate. Pollen and stigma mature synchronously and in close proximity within the unopened bud, favouring self-pollination. However, crosspollination often occurs too. Pressure on the wings of fully-open flowers by visiting insects forces the stigma and style to protrude through the keel. The exposed stigma remains receptive to pollen for several hours. Bees visit the flowers for both pollen and nectar. Of buds, flowers and young pods, 75 85% are shed under field conditions. Early blooming inflorescences are more productive than later ones, and basal nodes of the inflorescences are potentially more fruitful than terminal ones. Fruit setting proceeds until a 'capacity set' is attained; remaining reproductive structures then abscise. Lima bean can fix nitrogen by symbiosis with Bradyrhizobium bacteria. Ecology Lima bean is particularly well suited to low-altitude humid and sub-humid tropical climates, but it can be grown in a wide range of ecological conditions. It is found in warm temperate zones as well as in arid and semi-arid tropical regions. Lima bean is found from sea-level up to altitudes higher than 2000 m. It comprises photoperiod-insensitive types that flower in day lengths up to 18 hours, and short-day types that require a daylength as short as hours to initiate flowers. Optimum temperatures are C; frost is not tolerated. Average rainfall is mm per year, but once established the crop tolerates as little rainfall as mm. Some types are considered very drought resistant, due to their deep, well-developed root system. Lima bean prefers well-aerated, well-drained soils with ph However, some cultivars tolerate acid soils with ph as low as 4.4. Propagation and planting Propagation of Lima bean is by seed. Seed weight varies between 30 g and 300 g per 100 seeds. Bush types are usually spaced cm within rows and cm between rows, while climbing types may be planted on hills cm apart. Lima bean may be planted in groups of 3 4 plants, separated by at least 1 m. The normal seed rate varies between kg/ha for smallseeded cultivars and kg/ha for largeseeded types. The planting density in southwestern Madagascar is (500-)2100(-4500) pockets per ha, with 3-5 seeds per pocket. In the more humid tropics, Lima bean is mostly cultivated in home gardens or intercropped with cereals (maize, sorghum), root and tuber crops (yam, cassava) or other crops (e.g. banana, groundnut, sugar cane). Sole cropping is more common in drier areas (Madagascar, Peru). In intercropping, seeds are often placed

142 144 CEREALS AND PULSES in the same hill as the companion crop. Management Weeding is necessary during initial growth of Lima bean. In Africa it is usually done 1-3 times. In humid areas, climbing types are staked. Unstaked plants tend to have lower yields because of poor foliage display, and lower seed quality because the pods may be resting on the ground. In parts of West Africa, where Lima bean is intercropped with maize or sorghum, the cereals provide support for climbing. Lima bean may also be planted after yam, with the stake of the previous yam crop providing support. In drier conditions (Madagascar, California and Peru), Lima bean may be left prostrate and irrigated 2-4 times before maturity. In the south-western part of Madagascar Lima bean is planted on alluvial soils in mounds or ridges as the flood waters from a nearby river recede, or is irrigated from a river. Fertilizer is not usually applied in tropical areas. If fertilizer is applied, this is often done at planting, in bands below and adjacent to the seeds. Supplemental nitrogen and phosphorus may be side-dressed at the early bud stage and during fruit development. Lima bean may be planted after a wellfertilized crop, thus benefiting from residual fertilizer, especially phosphorus. Diseases and pests In the tropics the most serious diseases of Lima bean are web blight caused by Rhizoctonia solani, Fusarium root rot caused by Fusarium solani, anthracnose caused by Colletotrichum spp., downy mildew caused by Phytophthora phaseoli, bacterial blight due to Xanthomonas campestris pv. phaseoli and two viral diseases: Lima bean golden mosaic virus (LGMV) transmitted by white flies (Bemisia sp.) and Lima bean green mottle virus (LBGrMV) transmitted by aphids. The use of fungicides is recommended to control the fungal diseases. For bacterial blight the use of disease-free seed and crop rotation are the recommended control measures. Root-knot nematodes (mainly Meloidogyne incognita) can cause considerable yield reduction. Crop rotation with cereals can reduce the nematode population in the soil. Mexican bean beetle (Epilachna varivestis), aphids (mainly Aphis craccivora), leafhopper (Empoasca dolichi), flower thrips (Megalurothrips sjostedtî), legume pod borers (Maruca vitrata, Cydia sp. and Etiella sp.), and bruchids (Callosobruchus, Acanthoscelides and Zabrotes spp.) are serious pests. Chemical control measures (e.g. with endosulfan) have been recommended to control them. Harvesting Green and mature pods of the climbing Lima bean types are usually picked manually over an extended period (4-6 weeks). In drier areas (Madagascar), whole plants are cut and left to dry in the field before the pods are removed and the stems are fed to livestock. Mechanical picking is possible with erect cultivars maturing uniformly and setting pods well above the soil surface. Yield In the tropics, yields of dry seeds of Lima bean are kg/ha in intercropping and kg/ha in sole cropping. Yields in south-western Madagascar are (50-)400( 950) kg/ha. In experiments dry-seed yields in pure stands have reached kg/ha for the bush types and kg/ha for the climbing types. In Madagascar yields of 15 t green matter per ha have been obtained for use as fodder. Handling after harvest Pods of Lima bean are usually threshed by hand, and seed is cleaned and sorted. Care should be taken with threshing, as the seeds are brittle and easily damaged. In many tropical countries, seeds are sometimes stored in jars or baskets, and covered with a layer of sand or ash to protect them against bruchid infestation. Genetic resources There is a real risk of loss of genetic diversity of Lima bean in primary centres of diversity (Latin America) as well as in secondary centres of cultivated types (Africa and part of Asia). Over 2600 seed samples of Lima bean are available in the CIAT (Centro Internacional de Agricultura Tropical) collection at Cali (Colombia) with seeds coming mainly from South and Central America, West Africa (mainly Ghana and Nigeria), East and Central Africa, Madagascar, India, the Philippines and Myanmar. The wild and weedy types represent 3-5% of the total collection. Among the cultivated types, Sieva Group and Potato Group predominate, while accessions of the Big Lima Group come mostly from a few limited areas, such as the South American Andean region or the desert coast of Peru. According to IPGRI other large Lima bean collections exist in Indonesia (Research and Development Centre for Biology (RDCB), Bogor, 3850 accessions), the United States (Regional Plant Introduction Station, Washington State University, Pullman, Washington, 1060 accessions), Brazil (Empresa Brasileira de Pesquisa Agropecuâria (EMBRAPA ), Brasilia, 980 accessions), the Philippines (National Plant Genetic Resources Laboratory, University of the Philippines Los Banos (UPLB), College, Laguna,

143 PHASEOLUS accessions) and Costa Rica (Escuela de Biologia, Universidad de Costa Rica (UCR), San Pedro de Montes de Oca, 400 accessions). In tropical Africa small Lima bean collections are present in Ghana (Plant Genetic Resources Centre, Crops Research Institute, Bunso, 40 accessions; University of Ghana, Accra, 8 accessions), Togo (Institut de Recherches Agronomiques Tropicales et des Cultures Vivrières, Lomé, 36 accessions; Direction de la Recherche Agronomique (DRA), Lomé, 17 accessions), Guinea (Programme de conservation des ressources phytogénétiques, Institut de Recherche, Conakry, 34 accessions), Senegal (Institut Sénégalais de Recherches Agricoles (ISRA), Dakar, 23 accessions), Nigeria (International Institute of Tropical Agriculture, Ibadan, 15 accessions), Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 12 accessions) and Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa, 2 accessions). The National Botanic Garden of Belgium at Meise has been mandated by IPGRI as a base repository collection of wild Phaseolus, which includes wild accessions of Phaseolus lunatus and related species. Breeding Evaluation and breeding based on international collections were carried out at UTA (Ibadan, Nigeria) between 1973 and 1980, and later at CIAT (Cali, Colombia) between 1980 and 1992, the general objectives being to increase dry seed yield, upgrade resistance to pests and diseases and improve nutritional seed quality. Small-scale improvement programmes of Lima bean using local collections are being conducted in Ghana, Nigeria, DR Congo, Zambia and Madagascar. The adopted breeding methods are pure-line selection, bulk and population improvement; the target cropping systems include both sole cropping and intercropping systems. Erectness, resistance to lodging and to web blight are prime criteria to improve pseudo-determinate bush types. Earliness, photoperiod insensitivity, resistance to Lima bean golden mosaic virus and suitability for intercropping are being sought in climbing types. Some promising types in the humid tropics have been identified among the climbing forms. A large secondary genepool is available for improvement and the following wild species have been successfully crossed with Lima bean: Phaseolus jaliscanus Piper, Phaseolus maculatus Scheele, Phaseolus polystachyus (L.) Britton, Sterns & Poggenb. and Phaseolus salicifolius Piper. Introgression of useful genes of the wild taxa (e.g. resistance to Lima bean golden mosaic virus) has been observed in interspecific breeding material. Many commercial Lima bean cultivars have been developed in the United States. Prospects Because of its high yield potential, deep rooting and drought tolerance, Lima bean has good prospects in tropical Africa. Preliminary investigations have shown the great potential and the large genetic diversity of Phaseolus lunatus germplasm. Some progress in crop improvement has been made, mainly in areas outside the region of origin (for example in temperate climates of the United States). Much remains to be done in many regions of the tropics, particularly to develop more stable and higher-yielding cultivars for the humid, sub-humid and semi-arid tropics. Breeding efforts should consider separately the two major growth habits. The climbing indeterminate types usually give high but unstable dry-seed yield and require an expensive system of staking. In tropical regions, these types are mainly grown in intercropping systems with cereals or root and tuber crops. So far, few genotypes suitable for intercropping have been bred, which explains the poor performance of climbing Lima bean in such systems in spite of their high potential. The bushy pseudo-determinate types are more appropriate for sole cropping and intensive production systems. However, results are discouraging, particularly in humid tropics, due to unfavourable plant architecture (profuse branching, pods within the leaf canopy and severe lodging) and high susceptibility to diseases. The key factor to success would be to develop indeterminate bushy types with several traits of wide adaptation (such as deep rooting, drought tolerance, disease resistance and high yield potential). Research priorities should first be devoted to full exploitation of the large genetic variation available in the primary genepool of Mesoamerican and Andean origin. Exploitation of the alien genepools and selection in the interspecific populations should not be neglected when considering the challenge of high and stable yields in the humid tropics. Major references Baudoin, 1989; Baudoin, 1991; Baudoin, 2002; Baudoin & Mergeai, 2001b; Burkill, 1995; Fofana, du Jardin & Baudoin, 2001; Freytag & Debouck, 2002; Kay, 1979; Lyman, Baudoin & Hidalgo, 1985; Rollin, Other references Baudet, 1977; Baudoin, 1988; Baudoin, 1993; Berhaut, 1976; Duke,

144 146 CEREALS AND PULSES 1981; Ezueh, 1977; Fofana et al, 1999; Gillett et al., 1971; Hauman et al., 1954a; Hepper, 1958; Holland, Unwin & Buss, 1991; ILDIS, 2002; Kee, Glancey & Wootten, 1997; Maquet, Vekemans & Baudoin, 1999; Maquet et al., 1997; Paul, Southgate & Russell, 1980; Polhill, 1990; Schmit et al, 1993; Westphal, 1974; Williamson, Sources of illustration Baudoin, Authors J.P. Baudoin Based on PROSEA 1: Puises. PHASEOLUSVULGARIS L. (common bean) Protologue Sp. pi. 2: 723 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 22 Vernacular names Common bean, haricot bean, kidney bean, navy bean (En). Haricot commun, haricot (Fr). Feijäo, feijoeiro (Po). Mharagwe (Sw). Origin and geographic distribution Common bean originated in Central and South America. Small-seeded and climbing ecotypes are found in the wild in northern Argentina and Central America. Common bean was independently domesticated in both Central America (Mexico and Guatemala) and in the South American Andes (mainly Peru). The resulting gene pools are distinct. Archaeological evidence indicates that common bean was a domesticated crop already in 6000 and 5000 BC in Peru and Mexico, respectively. Common bean was taken to other parts of the world since the 16 th century. Portuguese traders probably introduced common bean to Africa from the 16 th Phaseolus vulgaris - planted century through Sofala (Mozambique), Zanzibar and Mombasa, from where it was carried to higher altitude areas of the interior by slave trading caravans and merchants. Common bean became well established as a pulse crop in parts of Africa before the colonial era. Genetic diversity of common bean and its pathogens and linguistic evidence indicate that it became a major crop in Central African highland areas (e.g. in Rwanda and Burundi) earlier than in other parts of Africa. Nowadays, common bean is a crop of global importance, especially in North and South America, Europe and Africa. The crop is of significance in many African countries and most intensively grown in the Great Lakes areas of Central Africa. In tropical Africa common bean is a major food crop in urban as well as rural areas. Uses The mature dry seeds of common bean are eaten worldwide as a pulse and the immature pods and seeds as a vegetable. In tropical Africa common bean is primarily produced and consumed as a pulse. The nutritional value of the seeds is recognized, but common bean is also important for adding diversity and flavour to carbohydrate-rich meals, such as those based on maize or banana. It is the major protein source in various countries, e.g. in Rwanda, Burundi and Kenya. Although common bean is sometimes recognized as the 'meat of the poor', it is also much appreciated by wealthier consumers. In tropical Africa common bean is most typically consumed boiled, often with seasoning and some oil added. It may also be mashed or made into soup. In many parts of the world the dry seeds of common bean are canned, either alone or in tomato sauce. The leaves of common bean are sometimes eaten as a vegetable, e.g. during the hunger months of the year when not much food is available, but relatively few cultivars have leaves of sufficient tenderness. Crop residues are often used as fodder. In Mali a powder of carbonized seeds is applied to wounds. In temperate regions of the world Phaseolus vulgaris is mainly grown for the green immature pods (French bean), which are canned, frozen or eaten fresh. In tropical Africa immature pods are mostly produced as a market crop. A separate article in PROTA 2: 'Vegetables' deals with vegetable aspects of Phaseolus vulgaris. Production and international trade Reliable production statistics for dry common bean

145 PHASEOLUS 147 are difficult to obtain, as its production is often lumped together with that of other Phaseolus species. In 2000 the annual world production of common bean was estimated by FAO to be 8.3 million t; the largest producer is Brazil. Africa produces about 2 million t annually on about 3.5 million ha. Large producers (100, ,000 ha annually) in tropical Africa are DR Congo, Rwanda, Burundi, Ethiopia, Kenya, Uganda, Tanzania, Malawi, Angola and Mozambique; smaller producers (2, ,000 ha) are Cape Verde, Niger, Cameroon, Sudan, Zambia and Zimbabwe. Most common bean produced in tropical Africa is consumed by the producer, but 40% may be marketed to supply urban areas and for export with a farm gate value of over US$ 200 million per year. Trade with neighbouring countries is important. For example, significant amounts move from Uganda to Kenya, Rwanda and Sudan, but Uganda may import from these countries when localized deficits occur. An example of longer distance trade of common bean is from Kivu in eastern DR Congo to Kisangani and down the Congo River to Kinshasha. Some common bean production is for specialized export markets, e.g. in Ethiopia for export to Europe and the Middle East, and in northern Tanzania for export to Europe. Properties A typical composition of common bean per 100 g edible portion is: water 11.3 g, energy 1218 kj (291 kcal), protein 21.4 g, fat 1.6 g, carbohydrate 49.7 g, dietary fibre 22.9 g, Ca 180 mg, Mg 180 mg, P 310 mg, Fe 6.7 mg, Zn 2.8 mg, carotene trace, thiamin 0.45 mg, riboflavin 0.13 mg, niacin 2.5 mg, vitamin B mg, ascorbic acid trace (Holland, Unwin & Buss, 1991). The essential amino acid composition per 100 g edible portion is: tryptophan 210 mg, lysine 1540 mg, methionine 240 mg, phenylalanine 1130 mg, threonine 860 mg, valine 990 mg, leucine 1640 mg and isoleucine 890 mg (Paul, Southgate & Russell, 1980). Common bean is deficient in the essential amino acids methionine and cystine. Composition alone is not a reliable indicator of its food value as common bean is not very digestible. Much of the phosphorus is phytate-bound and the protein is only 55-65% digestible. Common bean generally requires a long cooking time and may have 'hard-to-cook' properties, which may be due to genetic and environmental factors. Common bean contains antinutritional compounds, such as lectins (haemagglutinins) and trypsin inhibitors, but both are inactivated by proper cooking. It also contains tannins and flatulence-inducing compounds. Common bean starch has shown cholesterollowering effects in rats, whereas lectins have shown in-vitro inhibitory action against HIV-1 reverse transcriptase. A decoction of the pods has shown hypoglycaemic effects in rabbits. Seed coat compounds (methanol extracts, tannin fractions and pure flavonoids) have shown antioxidant activity. Description Climbing, trailing or erect and bushy annual herb, slightly pubescent; taproot well developed, with many lateral and adventitious roots; stem up to 3 m long, angular or nearly cylindrical. Leaves alternate, 3-foliolate; stipules triangular, small; petiole up to 15(-30) cm long, grooved above, distinctly thickened at base, rachis (1.5-) ( 6) cm long; stipels small; leaflets ovate, (5-)7.5-14(-20) cm x 5-10( 15) cm, lateral ones asymmetrical, central one symmetrical, entire, slightly pubescent, 3- veined from the base. Inflorescence an axillary or terminal false raceme up to 15(-35) cm long, with flowers arranged along the rachis in pairs or solitary. Flowers bisexual, papilionaceous; pedicel up to 1 cm long, slender, with ovate bracteoles; calyx campanulate, tube c. 3 mm long, lobes triangular, 2-3 mm long; corolla white to pale purple or red-purple, standard very broadly obovate, hood-shaped, cm long, wings obovate, c. 2 cm long, keel sharply upturned, c. 1 cm long; stamens 10, 9 fused and Phaseolus vulgaris - branch; 3, seeds. Source: PROSEA 1, inflorescence; 2, fruiting

146 148 CEREALS AND PULSES 1 free; ovary superior, c. 0.5 cm long, laterally compressed, style upturned and spiralled, with collar of fine hairs below the ellipsoid stigma. Fruit a linear pod up to 20 cm long, straight or more commonly curved with a prominent beak, fleshy when immature, green or yellow, sometimes red, purple or with purplish stripes, (2-) 5 7( 12)-seeded. Seeds globose to kidneyshaped, ellipsoid or oblong, (-2) cm long, black, brown, yellow, red or white, sometimes with speckled, flecked or saddled patterns; hilum oblong to elliptical. Seedling with epigeal germination; cotyledons oblong, thick; first two leaves simple and opposite, subsequent leaves alternate, 3-foliolate. Other botanical information Phaseolus comprises about 50 species, most of them in the Americas. Phaseolus vulgaris is closely enough related to some other Phaseolus species, e.g. Phaseolus coccineus L. (runner bean) and Phaseolus acutifolius A.Gray (tepary bean), to make interspecific hybridization possible. Andean types of Phaseolus vulgaris tend to have larger seeds and leaves than the Central American types. All growth habits are found in each gene pool, but determinate bush types and climbing types are more common in the Andean than in the Central American pool. In tropical Africa some genetic diversity is found that is not found in the Americas. Erect bush bean types are most common where mechanical harvest is practised but also in smallholder agriculture. Climbing types are largely restricted to high altitude areas, especially in south-western Uganda, Rwanda, Burundi and eastern parts of DR Congo, but they are also grown in northern and western Malawi, northern and southern Tanzania and northern Zambia. Indeterminate trailing or semi-climbing types are common in most bean growing areas and prevail under growing conditions that are marginal due to high temperatures, water deficits and low soil fertility. Red, mottled, large-seeded cultivars are most common in tropical Africa, followed by cultivars with red, small to medium-sized seed. Other seed types may comprise 50% of the production. Black-seeded and white-seeded cultivars are not popular because of the colour of the food preparations. Growth and development For seed germination of common bean the soil must be warmer than 12 C, with optimal emergence occurring at soil temperatures of C. Plant growth habits are broadly grouped into determinate or indeterminate and bush or climbing. Flowering in common bean generally starts days after sowing. Self-fertilization is the rule, but with 1-3% outcrossing. Immature pods for vegetable use can be harvested days after flowering. The seedfilling period may take days. The length of the crop cycle ranges from days for determinate types and may be as long as days for indeterminate climbing types. Several Rhizobium species fix nitrogen with Phaseolus vulgaris, including Rhizobium leguminosarum bv. phaseoli, Rhizobium etli and Rhizobium tropici. The nitrogen-fixing ability of common bean is often considered poorer than that of other pulses such as cowpea, soya bean and groundnut, although fixation rates up to 125 kg of N per ha have been recorded. Ecology In tropical Africa common bean is well adapted to elevations of m, with mean temperatures during the growing season of C. Still, 20% of the common bean production in tropical Africa takes place at a mean temperature higher than 23 C. The crop can withstand occasional daytime temperatures of 35 C, but this often results in flower abortion. Growth stops below 10 C and the plant is killed by frost. At latitudes higher than 10 Phaseolus vulgaris may be grown at low altitudes during cooler months, generally with irrigation, and usually for immature pod harvest. Common bean production occurs with 250 mm mean rainfall during the growing season but 65% of the production is estimated to occur in areas with an average rainfall higher than 400 mm during the season. Occasional water deficits severely reduce common bean yield. More important constraints than water deficits are diseases that are favoured by humid conditions. Common bean genotypes vary for photoperiod sensitivity (short day plants or day neutral); photoperiod sensitivity is typically greater in genotypes of Andean origin than in Meso-American ones. Common bean prefers medium-textured, welldrained soils over 0.5 m deep. It is sensitive to soil acidity, including the associated aluminium and manganese toxicities. The optimum ph is , but most common bean production in tropical Africa is at soil ph 5-6 and 20% takes place on soils with ph below 5. Common bean production in tropical Africa occurs mostly under conditions of P deficiency. Where Phaseolus species have not grown previously, symbiotic N-fixation may be inadequate to meet the N requirement of the plants. Propagation and planting Common bean

147 PHASEOLUS 149 is normally propagated by seed, but vegetative propagation using stem cuttings is possible. The 1000-seed weight is g. Common bean may be sown by broadcasting and row planting. Sole-crop sowing rates range from 150, ,000 seeds per ha. With intercropping, sowing rates are less than for sole cropping. Indeterminate climbing common bean is sown 3 6 seeds per planting hole in rows cm apart with cm spacing within the row. Seeds are normally sown 3-4 cm deep, but as deep as 7 cm if the soil surface is dry and not too heavy or prone to crusting. Often mixtures of different seed types are sown, e.g. in Rwanda, Tanzania and Malawi. In traditional agriculture the land is prepared by hand or animal traction before sowing. Cultivation is mostly on the flat, but sowing on hills or ridges may be practised where the soil is heavy or the groundwater table is high. Only about 30% of the common bean production area in tropical Africa is planted as a sole crop. Intercropping with maize, banana and root or tuber crops is important with these intercrop associations accounting for 40-50%, 10-20% and 10-20%, respectively, of the common bean production area. Less common is intercropping with sorghum, millet, pea, faba bean, coffee and other crops. Climbing cultivars are more often produced in sole cropping than non-climbing types, but the dense foliage in sole cropping easily creates a humid environment promoting diseases. Common bean is sometimes grown as a relay crop on residual moisture, e.g. in Malawi and southern Tanzania. Management For climbing cultivars of common bean, 2 m high poles (usually straight branches or stems of bamboo or Pennisetum) are placed after emergence to support the plants. The crop is usually weeded once or twice, after which its canopy is sufficiently developed to suppress weeds. Earthing-up is often done at about 3 weeks after sowing. This should be done carefully, because common bean is liable to damage to the collar of the plant. Irrigation is uncommon except at higher latitudes with winter (dry season) production. Common bean is rarely fertilized in tropical Africa although N and P deficiencies are major constraints. Adequate P nutrition is important for symbiotic N- fixation and there is often economical response to 20 kg N and 22 kg P per ha. Although much of the common bean production is on acid soils, the use of lime to amend these soils is uncommon. The crop is grown in rotation with other annual or short-lived perennial crops. The rotated crops are typically cereals, other pulses and root or tuber crops. Diseases and pests Common bean is extremely susceptible to diseases and pests and more than 50% of the production in tropical Africa is estimated to be lost every year. The seedborne fungal diseases angular leaf spot (Phaeoisariopsis griseola) and anthracnose (Colletotrichum lindemuthianum), and the bacterial diseases common bacterial blight (Xanthomonas campestris pv. phaseoli) and halo blight (Pseudomonas savastanoi pv. phaseolicola, synonym: Pseudomonas syringae pv. phaseolicola) are each among the top constraints of common bean production. Estimated total yield loss attributed to these diseases is more than 1 million t per year in sub-saharan Africa. Angular leaf spot and anthracnose are sensitive to many fungicides, but smallholder farmers generally do not use chemicals for common bean disease control. Cultivars vary in their reaction to these diseases. Pre- and postemergence damping off caused by root rot complexes (Pythium aphanidermatum, Rhizoctonia solani (group AG4) and Fusarium solani f.sp. phaseoli) is very important in areas with intensive common bean production and low-fertility soils. Improving nutrient supply and sowing resistant or tolerant cultivars are effective methods of reducing losses to root rot. Bean common mosaic virus (BCMV) is an aphidtransmitted and seedborne virus and has been estimated to cause 180,000 t yield loss per year in sub-saharan Africa. Resistance to BCMV is controlled by a single dominant gene, but this gene causes susceptibility to bean common mosaic necrosis virus (BCMNV; also known as black root) that is indigenous to Africa. These closely related viruses each have more than one pathogenicity group. Resistance to all groups can be achieved by deploying 2 or more recessive genes. Sowing of disease-free seed can be useful in control of seedborne diseases, but such seed is scarce. Bean rust (Uromyces appendiculatus), Ascochyta blight (Phoma exigua), powdery mildew (Erysiphe polygoni), floury leaf spot and web-blight (Rhizoctonia solani group AGI) together may cause yield losses of 600,000 t/year in sub-saharan Africa. The most important insect pests are bean flies or bean stem maggots (Ophiomyia spp.), especially at early growth stages and when plants are stressed by water and nutrient deficits. Bean flies can be controlled by treating seed with a systemic insecticide, such as imidaclo-

148 150 CEREALS AND PULSES prid or endosulphan, either as a seed dust or as a spray shortly after seedling emergence. In Africa cutworms (Agrotis spp.) and caterpillars (Spodoptera spp.) may be a problem especially in soils amended with farmyard manure, a common practice by smallholder growers. Thrips (Frankliniella occidentalis, Frankliniella schultzei and Megalurothrips sjostedti) and pod borers (Helicoverpa armigera, Maruca testulalis and Clavigralla spp.) cause 80,000 90,000 t and 130, ,000 t yield loss per year, respectively, in sub-saharan Africa. Thrips, particularly Frankliniella occidentalis, are difficult to control as they are resistant to many commonly used pesticides. Pod borers are easily controlled by Bacillus thuringiensis products. Aphids (Aphis fabae and Aphis craccivora) are among the top 10 constraints to common bean production and are worse under dry conditions. Ootheca foliage beetle causes widespread damage in sub-saharan Africa. Whitefly (Bemisia tabaci), a Madagascan bean leaf roller called 'cigarier'(apoderus humeralis) and painted lady (Vanessa cardui, synonym: Pyrameis cardui) are of local importance. Bruchids (Zabrotes subfasciatus and Acanthoscelides obtectus) are major pests of stored common bean and have been attributed with being the sixth main cause of yield loss (250,000 t/year) in sub-saharan Africa. Pest management typically involves the integration of several low-cost practices including crop rotation, intercropping, sowing of resistant or tolerant cultivars, and insecticide use. Harvesting Common bean may be harvested while most pods are still green but near physiological maturity, for an early harvest of a fresh, easy to cook pulse product, but most crops are harvested when mature. In tropical Africa harvesting is nearly all by hand. Nonclimbing common bean plants are usually uprooted when most of the pods are dry, bundled, and carried home. Pods of climbing types are normally harvested by hand as they mature, with repeated harvests over several weeks. Yield Average common bean yields are about 1.5 t/ha in Europe and industrialized countries of Asia, 1 t/ha in North America and 0.7 t/ha worldwide. Average yields in tropical Africa are often around 0.6 t/ha. Under the best growing conditions, yields of 2.5 and 5 t/ha for non-climbing and climbing types, respectively, are achievable. Under irrigation in Malawi, for instance, yields of 3.8 t/ha have been obtained. Handling after harvest Smallholder farmers transport the common bean harvest from the field to their home to be spread on the ground and dried in the sun. After drying, threshing may be by beating with long sticks, driving over heaps of harvested plants with a tractor, or, less commonly, with a threshing machine. Before being stored, common bean seed is often dried in the sun to destroy bruchids and to reduce moisture content for better storage. Prolonged drying can, however, induce a hard-to-cook condition. In some regions seed is sorted to lots of single seed types, while elsewhere complex mixtures of seed types are intentionally produced and consumed. Seeds may be stored with wood ash, tobacco leaves or ash from bean stems. Genetic resources Common bean is threatened by genetic erosion due to non-traditional farming practices where relatively few genotypes are produced in pure stands, and, especially in Latin America, to displacement of common bean by more profitable crops. In-situ conservation can be of importance especially in countries like Rwanda where many landraces are found under diverse conditions and where they are often grown in complex mixtures of as many as 20 seed types. The largest ex-situ collection of Phaseolus is at the International Center for Tropical Agriculture (CLAT) near Cali, Colombia. It holds over 40,000 accessions of which over 35,000 are of Phaseolus vulgaris. This was estimated to account for 50-75% of the variability occurring in the centres of diversification for domesticated types, but only less than 30% of diversity of wild types. Germplasm collections held in Africa include: Bunda Agricultural College, Lilongwe, Malawi (6000 accessions), National Genebank of Kenya, KARI, Kikuyu (3000 accessions) and Institut des Sciences Agronomiques du Rwanda, Butare (3000 accessions). African national breeding programmes (e.g. in Uganda) have smaller landrace collections. Breeding Common bean breeding programs in Africa and elsewhere have as their goal to improve yield potential; much of the progress is through improved tolerance or resistance to biotic and abiotic constraints. Improved resistance to diseases has been the main breeding goal and much success has been achieved, although resistance is often not durable due to genetic diversity and adaptive ability of the pathogens. Resistance to common bacterial blight has been introduced from Phaseolus coccineus and Phaseolus acutifolius. Improved insect resistance has been another major

149 PlSUM 151 breeding goal. Wild Phaseolus species have been useful sources of genes, such as for resistance to the bruchid Zabrotes subfasciatus. Breeding for tolerance to abiotic stresses has gained in importance and lines with superior tolerance to acid soils, and others efficient in N or P use, have been released in Africa. Promising progress in breeding for drought tolerance is being achieved where deep root systems are combined with efficient transport of carbohydrates from leaves to seed under drought stress. Progeny produced from crosses between the Andean and Meso-American gene pools typically is weak and of low productivity, but breeders have developed superior lines and parents through inter-pool crosses which have superior traits from each pool. Resource-constrained breeding programmes in Africa have benefited from regional and international collaborative efforts, such as from germplasm generated at CIAT. Efficiency of breeding common bean is improving with increased use of molecular markers. The 'Phaseomics' initiative facilitates collaboration among research institutions in the development of a cdna library and sequencing of the common bean genome. In-vitro regeneration of common bean for breeding purposes is possible using different expiants, including shoot tips, petioles, seedlings, embryonic axes, cotyledons, seedling nodes and meristematic calli. No confirmed reports exist of stable transgenic common bean plants based on Agrobacterium tumefaciens systems, but transgenic plants have been obtained by particle bombardment. However, the most efficient way to improve common bean with gene technology is probably to use Phaseolus acutifolius, which can be routinely transformed using Agrobacterium, and to cross the resulting transgenic plants with common bean using embryo rescue techniques. Prospects Common bean is the most consumed pulse globally and a very important crop in tropical Africa, especially in Central, East and southern Africa, both for its nutritional value and its market potential. It is especially important to smallholder farmers and women, who often are responsible for the common bean crop. Regional trade of common bean is of economic significance for some countries and there is also some common bean production in tropical Africa for export to Europe and the Middle East. There is no reason to expect that the importance of common bean will decrease in the future; in tropical Africa the demand is even likely to increase as population increases. Common bean production in tropical Africa is constrained by susceptibility to diseases and pests. Breeding for resistance to or tolerance of diseases and pests has achieved considerable progress, but work remains to be done as resistance is often not durable. Breeding for better tolerance to abiotic stresses, such as aluminium toxicity, and for more efficient use of inadequate soil water and nutrients, is also necessary to improve production both on marginal and on productive soils. Biotechnological tools will play an increasingly important role in common bean breeding, e.g. the use of molecular mapping to locate resistance genes. Major references Abate & Ampofo, 1996; Allen, Buruchara & Smithson, 1998; Baudoin et al, 2001; Gepts & Debouck, 1991; Hidalgo, 1991; Messiaen & Seif, 2004; Popelka, Terryn & Higgins, 2004; Shellie-Dessert & Bliss, 1991; Smartt, 1989b; Wortmann et al, Other references Beninger & Hosfield, 2003; Chacon S., Pickersgill & Debouck, 2005; Debouck & Smartt, 1995; Freytag & Debouck, 2002; Fukushima et al., 2001; Giller, 2001; Gillett et al, 1971; Graham & Ranalli, 1997; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hidalgo & Beebe, 1997; Holland, Unwin & Buss, 1991; Johnson, Pachico & Wortmann, 2003; Kay, 1979; Mackinder et al., 2001; Martinez Romero, 2003; Paul, Southgate & Russell, 1980; Qi, Smithson & Summerfield, 1998; Roman- Ramos, Flores-Saenz & Alarcon-Aguilar, 1995; Wang & Ng, 2000; Westphal, Sources of illustration Smartt, 1989b. Authors CS. Wortmann PlSUMSATIVUM L. Protologue Sp. pi. 2: 727 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 14 Vernacular names - Field pea, pea (En). Pois, pois sec (Fr). Ervilha (Po). Njengere, njegere (Sw). - Garden pea, pea, petit-pois (En). Petit pois (Fr). Ervilha (Po). Njengere, njegere (Sw). - Sugar pea, pea pod, snap pea, snow pea, mange-tout (En). Pois mangetout, pois gourmand (Fr). Ervilha torta (Po). Origin and geographic distribution The origin and progenitors of Pisum sativum are not well known. The Mediterranean region, west-

150 152 CEREALS AND PULSES Pisum sativum -planted ern and central Asia, and Ethiopia have been indicated as centres of origin. Recently FAO designated Ethiopia and western Asia as centres of diversity, with secondary centres in southern Asia and the Mediterranean region. Archaeological evidence of the use of pea dating from 8000 BC has been found in the Fertile Crescent. The first cultivation of pea appears to have been in western Asia, from where it spread to Europe, China and India. In classical times Greek and Roman authors mentioned its cultivation as a pulse and fodder crop. Pea was already well known in the mountain regions of Central and East Africa before the arrival of the Europeans and was a well-established and important food crop in Rwanda and southwestern Uganda by The use of the edible pods was first described in the Netherlands and France during the 16 th century, whereas the use of immature seeds as a vegetable began in Europe a century later. At present, Pisum sativum is found in all temperate countries and in most tropical highlands. Field pea is extensively grown in the highlands of eastern Central Africa and East Africa (notably Ethiopia), and in southern Africa. In parts of Rwanda and Uganda it is the main pulse crop. Field pea is hardly grown in West Africa. In Africa garden pea and sugar pea are mostly considered exotic products. They are regionally of some importance, sugar pea more in Francophone countries, garden pea more in Anglophone countries. Imported canned garden pea seeds are available everywhere in food shops. Uses Three main types of pea cultivars can be distinguished: field pea, grown for the dry seeds; garden pea, grown for the immature green seeds; and sugar pea, grown for the immature pods. The dry seeds of field pea are first soaked in water to soften and are then boiled and consumed as a pulse dish. Alternatively, they are decorticated and split ('split peas') before boiling. They are also consumed roasted. The young pods of sugar pea are boiled for a few minutes only, to preserve their crispness; after boiling they may be stir-fried before consumption. The young seeds of garden pea are also boiled for a few minutes. They are commonly offered as canned or - in Western countries as deep frozen products. In Ethiopia the annual consumption per person of pea seeds is estimated at 6-7 kg. Main dishes include 'shiro wot' (split pea seeds ground and made into stew) and 'kik wot' (split pea seeds boiled and made into stew). Snacks include 'eshet' (fresh green field pea seeds either eaten raw or roasted), 'nifro' (boiled dry or fresh green pea seeds) and 'endushdush' (seeds soaked first and then roasted). In local markets white- and cream-coloured seeds are preferred for 'kik'-making, and grey-coloured seeds for 'shiro'-making. In Malawi and some Asian countries, the young shoots are used as a leafy vegetable. In Western countries dry, mature pea seeds are extensively used as animal feed. The haulms or straw after threshing are used as forage, hay, silage and green manure. Apart from being an important source of food and feed, pea plays a role in soil fertility restoration as a suitable rotation crop that fixes atmospheric nitrogen. The seeds of pea are claimed to have beneficial effects on many types of skin complaints; face masks made from crushed seeds are used to treat acne and wrinkled skins. Production and international trade FAO estimated the annual world dry pea seed production in at about 10.5 million t from 6.2 million ha. The main producers are Canada (2.1 million t/year from 1.1 million ha), France (1.9 million t/year from 400,000 ha), China (1.1 million t/year from 900,000 ha) and the Russian Federation (1.1 million t/year from 700,000 ha). The annual production in tropical Africa for this period was about 310,000 t from 470,000 ha. Here, the main producers are Ethiopia (135,000 t/year from 184,000 ha), DR Congo (65,000 t/year from 96,000 ha), Burundi (32,000 t/year from 49,000 ha), Tanzania (28,000 t/year from 63,000 ha), Uganda (18,000 t/year from 29,000 ha) and Rwanda (14,000 t/year from 30,000 ha). The annual world pro-

151 PISUM 153 duction of green pea seeds in was about 8.7 million t from 1.0 million ha, the main producers being India (3.4 million t/year from 300,000 ha), China (1.5 million t/year from 190,000 ha) and the United States (1.0 million t/year from 96,000 ha). In tropical Africa about 30,000 t green pea seed was produced annually from 6400 ha, mainly in Kenya (23,000 t/year from 5600 ha). Statistics on the international trade in pea seed are generally scanty, as they are mostly aggregated in 'pulse crops' as a whole. The main exporting countries are Canada, Australia, France and China. Canada focuses on the European stock feed market and in recent years on the food market in India. Australia focuses on the food markets and the domestic feed market. The top importers for pea feed or food are Spain, Bangladesh, Belgium, India, China, United States, Colombia, United Arab Emirates and Malaysia. Almost all the production in Ethiopia is consumed locally. Most sugar pea pods produced in the world are sold in local markets. Western countries import large quantities of sugar pea pods from developing tropical countries because locally produced ones are available for only a short time of the year and because of the high labour costs of picking. Kenya exports yearly 4500 t sugar pea pods to the European Union. Garden pea seeds are mostly exported as canned or frozen products from Western countries, e.g. the United States and France, but statistical data are not available. Properties Whole mature dried seeds of field pea contain per 100 g edible portion: water 13.3 g, energy 1269 kj (303 kcal), protein 21.6 g, fat 2.4 g, carbohydrate 52.0 g (starch 47.6 g), fibre 15.0 g, Ca 61 mg, Mg 120 mg, P 300 mg, Fe 4.7 mg, Zn 3.7 mg, carotene 245 ug, thiamin 0.6 mg, riboflavin 0.3 mg, niacin 3.0 mg, vitamin Be 0.13 mg, ascorbic acid trace (Holland, Unwin & Buss, 1991). The content of essential amino acids per 100 g food is: tryptophan 210 mg, lysine 1620 mg, methionine 210 mg, phenylalanine 1000 mg, threonine 860 mg, valine 1000 mg, leucine 1480 mg and isoleucine 930 mg (Paul, Southgate & Russell, 1980). The composition of wrinkled pea seeds is different from rounded ones; they have less starch (27-37 g) and more fat (5 g) and sugars. Antinutritional factors in pea seeds include trypsin inhibitors, haemagglutinins (lectins), tannins, oligosaccharides and phytate. Cultivars with a darker seed coat contain more tannin, which tends to decrease their digestibility. Raw garden pea seeds, immature taken from the pods (refuse 63%) contain per 100 g edible portion: water 74.6 g, energy 348 kj (83 kcal), protein 6.9 g, fat 1.5 g, carbohydrate 11.3 g (starch 7.0 g), fibre 4.7 g, Ca 21 mg, Mg 34 mg, P 130 mg, Fe 2.8 mg, Zn 1.1 mg, carotene 300 (Xg, thiamin 0.75 mg, riboflavin 0.02 mg, niacin 2.5 mg, folate 62 u,g, ascorbic acid 24 mg. Raw sugar pea pods, with the ends trimmed (refuse 8%) contain per 100 g edible portion: water 88.7 g, energy 134 kj (32 kcal), protein 3.6 g, fat 0.2 g, carbohydrate 4.2 g (starch 0.8 g), fibre 4.2 g, Ca 44 mg, Mg 28 mg, P 62 mg, Fe 0.8 mg, Zn 0.5 mg, carotene 695 p.g, thiamin 0.2 mg, riboflavin 0.15 mg, niacin 0.6 mg, folate 10 lg, ascorbic acid 54 mg (Holland, Unwin & Buss, 1991). Description Annual, climbing, glabrous herb up to 2(-3) m tall (up to 1.3 m for sugar pea types); taproot well developed, up to 1.2 m long, with many lateral roots; stem terete, with no or few basal branches, internodes hollow. Leaves alternate, pinnate, with l-3(-4) pairs of leaflets and ending in a usually branched tendril; stipules leaf-like, up to 8(-10) cm x 4 cm; petiole (2-)4-6(-7.5) cm long; leaflets shortly stalked, ovate to elliptical, cm x cm, entire to toothed, sometimes converted into Pisum sativum- 1, shoot with flower; 2, part of shoot with fruit; 3, seed. Source: PROSEA

152 154 CEREALS AND PULSES tendrils. Inflorescence an axillary, 1-3-flowered raceme. Flowers bisexual, papilionaceous; calyx with tube 4-8 mm long, lobes as long or longer than tube; corolla white to purple, standard 1-3 cm x cm, wings a little shorter than standard, keel much shorter; stamens 10, 9 united and 1 free; ovary superior, 1-celled, style curved, longitudinally grooved. Fruit an oblong-ovate pod cm x cm, pendant, 2-11-seeded. Seeds globose, sometimes wrinkled, 5-8 mm in diameter, varying in colour from uniform yellow (sugar pea), green (crinkled garden pea) to purple or spotted or cream-white, sometimes with black hilum. Seedling with hypogeal germination; cotyledons remaining within testa; first 2 leaves simple. Other botanical information Pisum comprises a few species and is related to Lathyrus, Lens and Vicia, from which it can be distinguished by its terete stems, very large stipules and longitudinally grooved style. Pisum sativum has long been studied by geneticists; Knight did his crossing experiments on it in 1787, and it was the subject of the pioneering work of Gregor Mendel in the 19 th century. Within Pisum sativum several varieties or subspecies have been distinguished. A classification in cultivar groups is more appropriate. Sativum Group is cultivated worldwide, including tropical Africa. Abyssinicum Group (Abyssinian pea) is cultivated in the northern (Tigray and Wollo) and south-eastern (Arsi) parts of Ethiopia; it is also grown in Yemen. The latter differs in having leaves with only one pair of leaflets (Sativum Group: 2-3 pairs), and smaller, red-purple flowers. It has slightly glossy seeds with a black hilum; these may mature earlier. Other cultivar groups, varieties or subspecies occur outside Africa; 2 of these represent wild populations from southern Europe and western Asia. Purple coloured flowers are associated with bitter tasting green seeds. For this reason nearly all garden pea cultivars are whiteflowered, while most field pea cultivars are purple-flowered and sugar pea cultivars can have white or purple flowers. Growth and development Pea seeds germinate at ambient temperatures of between 4 24 C, with C being optimal. In sugar pea cultivars flowers appear between the 6 th and 12 th nodes according to cultivar earliness, normally 5 7 weeks after emergence. At optimum temperatures, pods are ready for harvesting 12 days later. For garden pea the duration of the flowering period is 2 3 weeks in cultivars for mechanical harvesting, up to one month in garden cultivars. For field peas the period from emergence to dry seed harvest ranges from 3 6 months depending on cultivar and environment. Most field pea cultivars grown in Africa have an indeterminate growth habit. In a 2-season experiment with 63 genotypes in Ethiopia at 3000 m altitude, the period to flowering and maturity ranged from days and days, respectively. Pea flowers are self-pollinated, with usually less than 1% outcrossing. Pea is nodulated by Rhizobium leguminosarum. Ecology Pea requires a relatively cool climate, with average temperatures between7 24 C, and with optimum yields at average temperatures of C, although maximum rates of development and vegetative growth are reached at considerably higher temperatures. It can be grown at elevations above 1000 m near the equator, or at lower elevations (even in coastal areas) during the cool season at latitudes between Young plants can withstand frost if progressively hardened by lowering temperatures. Pisum sativum is grown in areas with an annual rainfall as low as 400 mm, but the optimum is mm/year. It is slightly susceptible to daylength, with long days promoting flowering. In most tropical circumstances it can be considered day-neutral. In Ethiopia rainfed field pea is grown at m altitude, because it suffers from diseases and drought at lower altitudes and from frost at higher altitudes. It is mostly grown in the main rainy season (June-December). In Uganda pea plants grow best at altitudes above 1800 m, and in Kenya optimum yields are obtained at m altitude. Pea grows on a wide range of soil types with moderate fertility levels, well drained and with ph , although some cultivars tolerate a ph up to 7.5. It is seriously affected by soil acidity, aluminium toxicity and waterlogging. Propagation and planting Pea is propagated by seed. The 1000-seed weight ranges from 100 g to 500 g. Sugar pea is sown in double rows 10 cm apart with 60 cm (30-80 cm) between the double rows. Within the rows the seed of small cultivars is sown 3 5 cm apart, for taller cultivars up to 10 cm apart. Garden pea is sown rather densely, with plant densities up to 80 plants per m 2. The seed should be sown 4-7 cm deep. Per ha kg of seed is required, with the highest rates for garden pea. Field pea is mostly broadcast in Africa. Even

153 PlSUM 155 though it does not require a fine seedbed, 2-3 ploughings with animal-drawn ploughs or one disc ploughing followed by two disc harrowings may be beneficial. Timely sowing is essential for optimum yields, since late-sown crops are often affected by low moisture availability and heavy aphid infestation at medium altitudes and by frost at high altitudes. In Ethiopia field pea is produced either as a sole crop or in mixed cropping with other crops, e.g. faba bean (Vicia faba L.). In the latter case, faba bean provides physical support and good aeration to field pea, whereas field pea suppresses weed growth. In Ethiopia mixed cropping of field pea with faba bean significantly slows down the rate of Ascochyta blight development and results in higher yields than pure stands. In the Kilimanjaro region of Tanzania pea is grown during the cool season in association with crops such as coffee, banana, tomato and maize. The same practice is found in parts of Kigezi District of Uganda. In Malawi (Ntheu District) it is also grown during the cool season, mostly as a garden crop in mixed stands with other crops, notably wheat. In the tropics, e.g. Rwanda and south-western Uganda, field pea is often the first crop after a fallow period. In temperate areas sugar pea is sown either in autumn or in early spring. Management Sugar pea plants are normally supported. The stems are not twining, but grasp the support with their tendrils. They do not need vertical poles, but the poles can be crossed, or the plants are supported by wire mesh, horizontal wires, vertical lattices or nets, depending on the potential height of the cultivar grown. Garden pea is seldom supported, field pea not at all. Weeds should be rigorously controlled. The critical period of weed competition is 3 8 weeks after emergence. Both annual and perennial grasses affect field pea. Weeds can be controlled by hand weeding where labour is cheap, whereas chemical weed control is more practical in large-scale production. Early land preparation can encourage weed seeds to germinate so that they can be destroyed in subsequent cultivation. Field pea normally needs no fertilizer N as the amount present in the soil and fixed by the plant is sufficient. The total uptake of a crop yielding 5-6 t of seed per ha is kg/ha P and kg/ha K. Young sugar pea and garden pea respond well to a starter dose of N fertilizer, even when nodulation occurs. An indicative fertilizer recommendation on light medium-rich alkaline soils is 40 kg N, 50 kg P, 150 kg K and 30 kg Mg per ha. Irrigation is necessary in dry conditions, e.g. 10 mm twice a week. Diseases and pests Ascochyta blight is a disease complex caused by Ascochyta pisi, Mycosphaerella pinodes (Ascochyta pinodes), and Phoma medicaginis (Ascochyta pinodella); it is widespread throughout the world. It is favoured by frequent rains and high humidity. Moderate levels of resistance have been detected in landraces and in the related Pisum fulvum Sibth. & Sm., which occurs wild in western Asia. Powdery mildew caused by Erysiphe pisi is widespread and important wherever pea is grown. Resistant cultivars have been developed. In sugar pea a recessive resistance gene is present in the cultivar 'Manoa Sugar' bred in Hawaii. Bacterial blight (Pseudomonas syringae pv. pisi) is common where pea is grown intensively and humidity is high. Downy mildew (Peronospora viciae) may develop at high altitudes where temperatures are between 1 C and 18 C. As Ascochyta blight, powdery mildew, bacterial blight and downy mildew are seedborne, the use of certified disease-free seed is essential. If own seed is to be used, it may be treated with a systemic fungicide to control Ascochyta blight and powdery mildew. In addition, wide row spacing, eradication of weeds, surface irrigation and rotations of three years or longer help to manage bacterial blight and other diseases. Aphanomyces root rot (Aphanomyces euteiches) is a major root pathogen of pea worldwide. It is extremely difficult to control, as no effective fungicides are available. The development of resistance/tolerance to this disease will be necessary for effective control. Another important soilborne disease is Fusarium wilt caused by Fusarium oxysporum f.sp. pisi, but cultivars resistant to this disease are available. Aphidtransmitted virus diseases include bean yellow mosaic virus (BYMV), pea seedborne mosaic virus (PSbMV), pea leaf-roll (BLRV - bean leafroll luteovirus) and pea enation mosaic virus (PEMV). Recent sugar pea cultivars bred in southern France are relatively tolerant to severe infestation by these viruses (e.g. 'Supermangetout' compared to the traditional 'Carouby de Maussane'). The pea cyst nematode (Heterodera goettingiana) can cause considerable crop loss; control measures are crop rotation and the use of chemicals. Insect pests attacking pea include cutworms (Agrotis spp.), aphids (including the pea aphid Acyrthosiphon pisum, a vector of many virus

154 156 CEREALS AND PULSES diseases, which has become a major pest in Ethiopia and Uganda), bollworms (Heliothis armigera and Spodoptera exigua) and the pea weevil (Bruchus pisorum). Bruchids (Callosobruchus spp.) are a major storage pest of field pea, e.g. in Ethiopia. The parasitic weed Orobanche crenata Forssk. causes crop losses in pea in the Mediterranean region. To control insect pests and diseases, integrated pest management (IPM) is recommended: use of resistant/tolerant cultivars; use of certified disease-free seed or seed treatment of own seed; keeping fields weed-free; appropriate fertilizing and irrigation; growing pea for seed in semi-arid and/or arid areas; regular monitoring of the crop; and judicious use of biocides. Harvesting Sugar pea pods and garden pea seeds are ready for harvesting 8-12 weeks from sowing, field pea seeds one month later. Pods of sugar pea are hand-picked every second day during a day period. Garden pea seeds are either handpicked or in large scale production for canning - machine-harvested. Late harvesting of field pea may result in shedding and rotting of pods and shattering of the seeds. Therefore, harvesting should be done at the appropriate stage: when the leaves begin to yellow, the lower pods begin to wrinkle, and the seed moisture content is reduced to 16-18%. In most parts of Africa where the time of harvest more or less coincides with the start of the dry season, it is easy to achieve low moisture contents while the crop is still in the field. Most field pea cultivars have an indeterminate growth habit and the pods do not mature simultaneously. Therefore, the harvested plants should be dried before threshing. In most parts of Africa (e.g. Ethiopia), harvesting of field pea is done with sickles, the crop is transported to threshing ground and stacked for a few days to dry in the sun. The stack is then spread on the ground and threshed usually by beating with sticks or by trampling with animals. Yield Yields of field pea range from less than 1 t/ha in Africa and South America to over 4 t/ha in Europe. The average world yield is around 1.7 t/ha. Under good growing conditions sugar pea yields of up to 8 t/ha edible pods per ha can be obtained. Garden pea may produce 4-7 t/ha young seeds. Handling after harvest The initial seed moisture content of field pea must be reduced to the required level of about 12% before storage. Optimum moisture content reduces the deterioration rate during storage and prevents or reduces attack by moulds and insects. The seed should be stored in a dry and cool place, free of pests and protected from absorbing moisture from the surroundings. In tropical Africa, e.g. in Ethiopia, pea seed is not stored for more than one season because of insect damage, particularly by bruchids. Small-scale farmers do not commonly use insecticides. Bins made of earth (smeared with cow dung) or wooden materials (sealed with mud) are the most commonly used storage structures in tropical Africa. Sugar pea pods can be kept for only 2 3 days at temperatures of C, but for more than 15 days at C in perforated plastic bags or crates covered with perforated plastic sheets. Garden pea seeds may be kept for 1 3 weeks at temperatures of 0-4 C and a relative humidity of 88-92%. Genetic resources A large genetic diversity has been found in Pisum sativum collections from both Africa (e.g. Ethiopia) and Asia (e.g. India). Genetic erosion in field pea is probably less than in cereals, because of less progress in cultivar development and hence less replacement of landraces by a few new cultivars. Many germplasm collections of pea are held all over the world. The world collection of cultivars and mutant forms of Pisum sativum is housed at the Nordic Gene Bank, Alnarp, Sweden (about 2700 accessions). Emphasis in the collection is on lines with multiple disease resistance, wild and primitive types, lines carrying structural mutations, breeding lines and cultivars of special interest. Large Pisum sativum collections are held in Australia (Australian Temperate Field Crops Collection, Horsham, Victoria, 6300 accessions), the Russian Federation (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 6200 accessions), Italy (CNR - Istituto di Genetica Végétale, Bari, 4100 accessions), the United States (Western Regional Plant Introduction Station, Pullman, 3500 accessions; Horticultural Sciences Department, NY State Agricultural Experiment Station, Geneva, 2500 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, 3400 accessions), and the United Kingdom (John Innes Centre, Department of Applied Genetics, Norwich, 2700 accessions). The largest collection of Pisum sativum germplasm in Africa is located at the Institute of Biodiversity Conservation, Addis Ababa, Ethiopia, with over 1600 accessions. Breeding All commercial cultivars of Pisum sativum are pure lines. The main breeding

155 PlSUM 157 objectives in temperate regions are colour and quality for fresh product markets and canning, mechanization and cold tolerance. Breeding in most parts of the tropics has an improved seed yield as a first priority through the development of productive cultivars tolerant/resistant to different stress factors and suitable for different agro-ecological conditions. Some progress has been made. In addition to improved yield potential, sources of resistance to powdery mildew have been identified. Attempts to transfer resistance to Ascochyta blight from a wild type have not been successful because of complications due to polygenic inheritance and linkage with other traits. The presence of physiological races of the pathogens is another problem. Manipulation of morphological traits has resulted in determinate types with even maturity, suitable for mechanization and semileafless types with reduced lodging. A peculiar mutant character, 'Afila', with tendrils in the place of leaflets has been introduced in commercial dwarf field pea cultivars. Breeding efforts during the past three decades in Africa have resulted in the release of a number of cultivars (obtained by introduction, hybridization and local selection), but most farmers still use their own farm-saved seed of local cultivars; well-known cultivars are 'Mitali' and 'Miseriseri'. In Ethiopia more than 15 cultivars, with superior yield potential, seed size, seed colour and disease resistance, have been released for different agro-ecological conditions. These cultivars include 'Holetta' (from local collection), 'Tegegnech' (introduced from Burundi), 'Hassabe' and 'Markos' (introduced from the International Center for Agricultural Research in the Dry Areas, ICARDA) and 'Adi', 'Milky' and 'Wolmera' (obtained by hybridization of adapted local cultivars with introductions from the United States and ICARDA). For sugar pea breeding the most urgent objective is powdery mildew resistance (available in 'Manoa Sugar') and to a lesser extent Ascochyta resistance (from green pea cultivars). The 'edible pod' character (absence of 'parchment' in the pod walls) is induced by two recessive genes. A mutation inducing thickening of this wall of up to 3 mm was recently introduced in American cultivars, giving rise to the 'sugar snap pea'. The 'sugar snap' character will be interesting if it appears attractive to consumers. It might also be interesting to introduce more new characters into sugar pea, e.g. true dwarfs which could be grown without support, or climbing semi-leafless types in order to increase yields by higher plant densities and to make fruit picking easier. Well-known cultivars of sugar pea in Africa are 'Sugar Snap', 'Carouby de Maussane', 'Oregon Sugar Pod', 'Shield' and 'Sugar Queen'. Some cultivars of garden pea are 'Alderman', 'Télévision' and 'Green Feast'. Many growers use their own seed originating from old introductions. A consensus genetic linkage map has been developed for Pisum sativum based on various linkage maps. Quantitative trait loci associated with, among others, seed yield, seed protein concentration, early maturity, lodging resistance, plant height and resistance to various biotic stresses (including Ascochyta blight, Aphanomyces root rot and Orobanche crenata) have been identified. Procedures for direct as well as indirect, callus-mediated somatic embryogenesis of pea have been developed for breeding purposes. Transgenic plants have been produced using Agrobacterium-based transformation vectors, e.g. to increase resistance to Callosobruchus chinensis, Callosobruchus maculatus and Bruchus pisorum by incorporating oc-amylase-inhibiting capacity from Phaseolus vulgaris. Prospects Field pea will remain important in Central and East Africa, as well as in temperate areas. It is a major and cheap source of protein, fixes atmospheric nitrogen, and plays an important role in farming systems by breaking cereal monoculture. A drawback is its susceptibility to diseases, which can best be counteracted by the development of resistant cultivars. As a potential export crop, it might represent a special opportunity in the years to come and the major pea-producing countries of tropical Africa could benefit from African (Morocco and Sudan), European (Netherlands, France and Greece), Middle Eastern (Israel and Yemen) and Asian (India and Pakistan) markets. Sugar pea and garden pea will become gradually more important in city markets in tropical Africa. Sugar pea is often considered a tastier vegetable than French bean and it could be interesting to develop its production for the domestic African market and for export. Garden pea could be produced locally on a larger scale to replace imports in canned form. Major references Cousin, 1992; Davies, 1989; Ellis & Poyser, 2002; Kay, 1979; Knight (Editor), 2000; Kraft & Pfleger, 2001; Nadolska-Orczyk & Orczyk, 2000; Telaye et al. (Editors), 1994; Thulin, 1989a; Westphal, Other references Aburjaj & Natsheh, 2003; AVRDC, 1992; FAO, 1998; Griga, 2002; Hanelt

156 158 CEREALS AND PULSES & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Hebblethwaite, Heath & Dawkins, 1985; Holland, Unwin & Buss, 1991; INRA, 2000; Kalloo, 1993; Kraft, Larsen & Inglis, 1998; Makasheva, 1983; Messiaen et al, 1991; Olivier & Annandale, 1998; Paul, Southgate & Russell, 1980; Pilet-Nayel et al, 2002; Pope, Polhill & Martins (Editors), 2003; Rubatzky & Yamaguchi, 1997; Schroeder et al., 1995; Valderrama et al, 2004; Wroth, Sources of illustration Davies, Authors C.-M. Messiaen, A.A. Seif, M. Jarso & G. Keneni SECALE CEREALE L. Protologue Sp. pi. 1: 84 (1753). Family Poaceae (Gramineae) Chromosome number 2n - 14 Vernacular names Rye (En). Seigle (Fr). Centeio (Po). Origin and geographic distribution The centre of origin of rye is not known exactly, but its current centre of diversity is in the mountainous areas of Afghanistan, Iran and the Middle East. Probably from there, rye was spread to the surrounding areas in Asia, northern Africa and later, just like wheat, to Russia, central and western Europe, where it is cultivated under temperate climatic conditions. Rye is a typical 'secondary crop': it was primarily a weed in wheat and barley fields, later adopted as a crop. It may have been domesticated before BC. Rye grains dating back to 6000 BC have been found in Turkey, but it is not known if these were from crop plants or Secale cereale -planted from weeds. Rye has been spread to all continents, especially to areas with temperate growing conditions. Occasionally it is cultivated at high elevations in the tropics and subtropics. In tropical Africa rye is cultivated in the highlands of East Africa and it has been grown successfully in Malawi. In Ethiopia rye is sparingly grown in the highlands of Arsi, where it was introduced through Swedish projects in the 1960s. Rye has been grown experimentally in Zambia and Mozambique, but apparently with little success. In Nigeria it has been tried as a fodder plant in the 1980s. Rye is also grown in Morocco, Algeria, Egypt and South Africa. Uses Rye grain is used as a food for humans, but on a worldwide scale it is more important as animal feed. The grain is processed into bread, cakes, crackers etc. For making bread, whole or broken grain can be used; for making cake, the grain needs to be milled. Rye flour is often mixed with wheat flour. In Africa rye flour is considered to make good porridge with an equal amount of maize flour; if used alone, it is considered too sweet. Rye grain can be sprouted to make malt for beer; several alcoholic beverages are prepared by distilling malted rye grains, e.g. rye whiskey in North America and vodka in Poland and Russia. Rye flour is used as filler for thickening soups and sauces. Rye grain is used as a fodder, especially in pig husbandry. Starch from the grain is industrially used in the production of glue, matches, gum for sizing paper, and plastics. Rye straw is harvested for feed (cattle), litter (in livestock sheds), thatching, mulching material, industrial use (paper/cardboard), packing material (nursery plants, cheese) and fuel. Immature rye is harvested as a whole crop forage and it is grown as a green manure or cover crop. In Europe and India rye is sometimes grown as a host plant for ergot (Clauiceps purpurea), which is used medicinally, e.g. against migraine. Rye pollen extracts are registered and commercially available as a medicine against benign prostatic hyperplasia in western Europe, Japan, Korea and Argentina. In Europe rye is under investigation as a biomass energy crop. Production and international trade According to FAO statistics, the total world rye production in amounted to 20 million t/year from 9 million ha. The main producers are the Russian Federation (5.6 million t/year from 3.2 million ha), Poland (4.2 million t/year

157 SECALE 159 from 1.9 million ha) and Germany (3.9 million t/year from 0.7 million ha). No production statistics are available for tropical Africa. World rye exports in amounted to about 1.8 million t/year. The main exporter was Germany (1.1 million t/year); the main importers were Japan (360,000 t/year), the Russian Federation (170,000 t/year), South Korea (170,000 t/year) and China (140,000 t/year). Properties Rye contains per 100 g edible portion: water 11.0 g, energy 1402 kj (335 kcal), protein 14.8 g, fat 2.5 g, carbohydrate 69.8 g, dietary fibre 14.6 g, Ca 33 mg, Mg 121 mg, P 374 mg, Fe 2.7 mg, Zn 3.7 mg, vitamin A 11 IU, thiamin 0.32 mg, riboflavin 0.25 mg, niacin 4.3 mg, vitamin Be 0.29 mg, folate 60 Xg and ascorbic acid 0 mg. The essential aminoacid composition per 100 g edible portion is: tryptophan 154 mg, lysine 605 mg, methionine 248 mg, phenylalanine 674 mg, threonine 532 mg, valine 747 mg, leucine 980 mg and isoleucine 549 mg (USDA, 2004). Rye cultivars comparatively rich in lysine are known. The main fatty acids are (per 100 g edible portion): linoleic acid 958 mg, oleic acid 280 mg, palmitic acid 271 mg and linolenic acid 147 mg. Due to the limited gluten content, bread made from rye flour has a compact structure; rye grain or grit is usually combined with wheat flour to improve the volume and texture of the bread. Because rye is not gluten-free, it is not suitable for inclusion in the diet of people with coeliac disease. Rye starch has a high water-absorbing capacity, making it suitable for use in adhesives. The feed value of rye grain is lower than that of other cereal grains, due to decreased feed intake, of which the causes are unclear. Therefore rye is used in mixtures with other grains. Rye straw is not very suitable as fodder because it is tough and fibrous. In a study on forage quality in the United States, the crude protein content of whole rye plants declined from 27.8% in the vegetative stage through 24.2% in the booting stage to 13.4% in the heading stage; the in-vitro dry matter digestibility in these three stages was 79%, 81% and 70%, respectively. Although rye pollen extracts are used to treat benign prostatic hyperplasia, results from longterm studies are not available and a metastudy did not show sufficiently strong evidence. Rye, its residues and aqueous extracts have allelopathic properties, enhancing the suitability of rye for use as a weed-suppressing cover crop. The main allelopathic compounds are 2,4- dihydroxy-l,4(2h)-benzoxazin-3-one and its decomposition product 2(3H)-benzoxazolinone. Weed-control effects of a rye mulch remain for days after the rye is killed. Description Annual tufted grass up to 1.5(- 3) m tall, often blue-green; stem (culm) erect, slender, hollow except at nodes, glabrous but pubescent near the spike, producing tillers and roots at base; root system extensive, penetrating to 2 m depth. Leaves alternate, simple; leaf sheath long and loose, with small auricles; ligule short, jagged; blade linear-lanceolate, cm x 1-2 cm, smooth or slightly scabrous. Inflorescence a terminal spike 7-15 cm long, curved, much awned, with spikelets alternating and closely inserted on a long zigzag rachis. Spikelets 2-flowered, with bisexual florets; glumes subulate, 1-veined, up to 1 cm long; lemma lanceolate, up to 2 cm long, tapering into a 2-8 cm long awn, 3(-5)-veined, keel prominently set with stiff bristles; palea about as long as lemma, awnless, scabrid on the keel; stamens 3; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain), oblongoid, mm x mm, narrowly grooved, short-pointed, pale brown, glabrous. Other botanical information Secale comprises 3 species, and is distributed from east- Secale cereale - 1, plant habit; 2, flowering spikelet; 3, floret without lemma; 4, fruiting spikelet; 5, grains. Source: PROSEA

158 160 CEREALS AND PULSES ern Europe to central Asia, with 1 species also occurring in South Africa. Only Secale cereale is cultivated. Secale strictum (C.Presl) C.Presl subsp. africanum (Stapf) K.Hammer (synonym: Secale africanum Stapf) is only found in a single locality in South Africa. It is recordedly eaten as a cereal. It is liked by livestock and birds and is considered a potential pasture plant. In the literature 2 subspecies have been distinguished within Secale cereale: subsp. cereale (comprising the cultivated types, with a tough rachis) and subsp. ancestrale Zhuk. (comprising the wild and weedy types, with a more or less fragile rachis, mainly found in western Asia). However, more subspecies have also been distinguished. Within cultivated rye there are many landraces (usually with long culms and small grains) and cultivars. Hybrids of rye and wheat called triticale (xtriticosecale) have been developed and these show a mix of characteristics from the parents, combining the hardiness of rye with the high yield and quality of wheat. Triticale is presently grown only locally in tropical Africa, e.g. in Ethiopia, Kenya, Tanzania and Madagascar, and also in northern Africa and South Africa. As a new food crop, it fell short of expectations, but it is becoming increasingly popular as a forage crop. Growth and development Rye germinates within 4 days at a soil temperature of 4-5 C, and more rapidly at higher temperatures. At the appearance of the fourth leaf, tillers and roots are formed to anchor the plant. Shoot initiation ceases as the plant enters the reproductive stage. Then, stem elongation starts and initiation and differentiation of the inflorescence take place. In each spike spikelets are initiated, of which bear 1-2 grains, resulting in grains per spike. Flowering lasts 3-5 days for a spike and 8-12 days for a rye crop. Rye is cross-pollinated by wind. The post-floral period for grain-filling is 4-5 weeks. The period from sowing to harvesting varies from 4-10 months. The duration of growth is largely dependent on temperature during reproductive development. In temperate regions so-called winter rye is planted in autumn to receive sufficient cold and short days to induce vernalization and reproductive growth; spring rye is planted in early spring and can be harvested after 4-6 months. Ecology Rye is a crop of temperate climates; in the tropics it is grown at high altitudes, e.g. at m in Ethiopia. Seedlings can endure frost down to -25 C. Tillering, shoot growth and flower initiation require rather low temperatures (10 15 C); for adequate growth during reproductive development the mean daily temperature must not exceed 20 C. Rye is tolerant to drought. Flowering is favoured by dry and sunny weather. Continuous rain, high humidity and low temperatures hamper pollination, causing incomplete grain set. Winter rye is a long-day plant; the reproductive development is stimulated by daylength increasing from 14 to 20 hours. Therefore, winter rye is mainly grown between N. Cultivars of spring rye are occasionally grown at high elevations in subtropical and tropical areas. They are less sensitive to daylength and do not need vernalization. Their flowering and seed set are satisfactory at a daylength of hours. Rye can be grown on most well-aerated soil types with a ph from 5-7.5; it is mainly grown on light, sandy and peaty soils. Propagation and planting Rye is propagated by seed. The 1000-seed weight is g. The optimal planting time for winter rye usually ranges from mid-september until mid- October in Europe. Seed can be broadcast by hand but needs to be covered to achieve adequate germination. Better conditions are created by drilling seed mechanically at a uniform depth of 2-4 cm in rows cm apart. Seed rates range from kg/ha to obtain an optimal density of plants/m 2. Spring rye needs to be planted as early as possible, if necessary even during winter, if soil conditions are suitable for preparing a seed-bed. Spring rye tillers poorly, so requires a higher seed rate ( kg/ha) than winter rye. Management Rye competes strongly with weeds, but they can cause problems at harvest. They can be controlled mechanically by harrowing or hoeing, or by herbicides during the tillering stage. Lodging can cause considerable damage. The amount of fertilizer required is largely related to the expected yield; about 20 kg N, 4 kg P and 13 kg K are removed from the soil per t grain yield. About 75-80% of the N and P is removed with the grains, whereas 75% of the K remains in the straw. N is often the most yield-limiting nutrient. For yields over 5 t/ha a split N-application is preferred. Diseases and pests Rye is considered relatively tolerant to diseases. Nevertheless, after germination snow mould (Fusarium nivale) can cause considerable plant losses and brown or leaf rust (Puccinia recondita f.sp. secalis) can severely damage leaves and stems. The most

159 SECALE 161 conspicuous disease is ergot (Claviceps purpurea), which infects the grain especially when grain set is poor; it produces alkaloidcontaining sclerotia. Grains with ergot are toxic, causing gangrenous or convulsive ergotism, and can make a rye stock unsuitable for human and animal consumption. No sources of resistance to ergot have yet been identified in rye. Other diseases include eyespot (Pseudocercosporella herpotrichoides), sharp eyespot (Rhizoctonia solani), powdery mildew (Erysiphe graminis), stem rust (Puccinia graminis), glume blotch (Septoria nodorum) and leaf blotch (Rynchosporium secalis). Most fungal diseases can be controlled by fungicides, but damage by snow mould, sharp eyespot and ergot can only be restricted by using healthy and disinfected seed. Resistance, e.g. to leaf rust and stem rust, is found in several rye cultivars, and resistance to these diseases has been transferred from rye to wheat through intergeneric crosses. Damage by viruses is of minor importance. The nematode Ditylenchus dipsaci can affect rye, but it is not common. Insect pests are not important in rye cultivation. Harvesting Time of harvest of rye is midsummer in Europe when the moisture content of the grain is below 15%. The crop can be harvested by hand; the method of harvesting, threshing, collecting and storing can be similar to that used for sorghum and millets. For combine harvesting, it is best to wait until the moisture content has dropped below 16%. However, to prevent loss of quality due to sprouting in the ear, the crop may be harvested at a higher moisture content (18-20%), especially if wet weather conditions prevail and delay ripening. Then subsequent drying will be required, in sheaves in the field or mechanically during storage. Yield Rye yields vary widely, from less than 1 t/ha in Africa, Latin America and Australia to over 5 t/ha in some western European countries. The world average yield is about 2 t/ha. Handling after harvest Low moisture content of the rye grain and low storage temperatures are desirable for long-term storage. The moisture content of the grain should be less than 13% if rye is to be stored for 6 months (without ventilation) at 15 C. If the stock is regularly ventilated, a moisture content of 14-15% may be acceptable. In temperate regions, such low moisture contents are often not reached at harvesting, and grain needs to be dried by warm air. Cleaning is commonly done before or during storage. After drying in the field, straw is usually baled and stored in barns or stacks for later use. Genetic resources Large germplasm collections of rye are kept in the Russian Federation (N.I. Vavilov All Russian Scientific Research Institute of Plant Industry, St. Petersburg, 2635 accessions), Germany (Institute for Plant Genetics and Crop Plant Research (IPK), Gatersleben, 1990 accessions), the United States (USDA-ARS National Small Grains Germplasm Research Facility, Aberdeen, Idaho, 1823 accessions) and Poland (Plant Breeding and Acclimatization Institute (IHAR), Radzikow, Blonie, 1366 accessions; Botanical Garden of the Polish Academy of Sciences, Warsaw, 1362 accessions). The only rye germplasm collections in Africa recorded by IPGRI are in South Africa (Division of Plant and Seed Control, Department of Agriculture Technical Service, Pretoria, 178 accessions; Small Grain Institute, Bethlehem, 52 accessions). Breeding Rye breeding programmes have given priority to winter types, and aspects as winter hardiness, straw stiffness, disease resistance and resistance to sprouting in the ear have received much attention. These breeding efforts have resulted in a considerable increase in grain yield and yield stability, shorter plants, reduced lodging and enhanced harvest index. Well-known cultivars include 'Petkus', 'Pearl', 'Steel' and 'King II'. Efforts to exploit heterosis for enhancing grain yield have resulted in hybrids that have entered commercial production with high-input management. Hybrids outyield conventional cultivars by 10-20%, but they demand more inputs (seed, crop protection). Tetraploid cultivars have been developed, with more vigorous growth and larger grains. Secale cereale has been crossed with Secale strictum with the objective of improving winter hardiness and resistance to drought and diseases. Perennial rye cultivars, intended for use as fodder, have also been developed by crossing the two species. For the production of ergot, male-sterile lines are used, facilitating the infection by the fungus. Rye is considered one of the most recalcitrant plants for tissue culture and genetic transformation. However, systems for the stable genetic transformation of rye using Agrobacterium tumefaciens or biolistic methods have been developed. It is possible to obtain large numbers of genetically identical plants by invitro regeneration using immature inflorescences as expiants. Genetic linkage maps of rye,

160 162 CEREALS AND PULSES on the basis of various marker types (RFLPs, AFLPs, RAPDs and microsatellite markers) have also been constructed. Genes conferring resistance to leaf rust have been identified. Prospects Rye may be inferior in several ways to the predominant world cereals (wheat, rice and maize), but it will continue to be an important crop because of its winter hardiness, tolerance to drought, ability to grow on poor soils, and consumer demand for baked products with the unique flavour of rye. There is considerable scope for improving yields. The application of high quality seed, new (hybrid) cultivars and advanced management practices can increase yield levels in the short term. The prospects of rye in tropical Africa seem limited. It has been tried in various countries, but its cultivation has not become important. Major references Darwinkel, 1996; Darwinkel, 1999; Frederiksen & Petersen, 1998; Froman & Persson, 1974; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Khlestkina et al., 2004; Kuip & Ponte (Editors), 2000; Popelka & Altpeter, 2003; Popelka, Xu & Altpeter, 2003; Smartt & Simmonds (Editors), Other references Acharrya, Mir & Moyer, 2004; Allkämper, 1984; Barnes & Putnam, 1987; Bosworth, Hoveland & Buchanan, 1986; Burgos & Talbert, 2000; Gibbs Russell et al., 1990; Launert, 1971; Maikhuri, Nautiyal & Khali, 1991; Masiunas et al., 1997; Musa, 1985; Nwankiti, 1984; Phillips, 1995; Roux et al., 2004; Raemaekers (Editor), 2001; Scholz & Eilerbrock, 2002; USDA, 2004; Vazquez & Linacero, 1995; Weston, 1996; Williamson, 1955; Wilt et al., Sources of illustration Darwinkel, Authors M. Brink Based on PROSEA 10: Cereals. SETARIA ITALICA (L.) P.Beauv. Protologue Ess. Agrostogr.: 51, 170, 178 (1812). Family Poaceae (Gramineae) Chromosome number 2n = 18 Vernacular names Foxtail millet, Italian millet, German millet (En). Panis, millet des oiseaux, millet d'italie (Fr). Painço, milho painço, milho painço de Itâlia (Po). Kimanga (Sw). Origin and geographic distribution Foxtail millet is an old crop, grown since 5000 BC in China and 3000 BC in Europe. It probably Setaria italica - planted evolved from the wild Setaria viridis (L.) P.Beauv. (green foxtail millet), and it was most probably first domesticated in the highlands of central China, from where it spread to India and Europe soon thereafter. Evidence for this origin, however, is not conclusive and its domestication may have taken place anywhere in the area extending from Europe to Japan, perhaps even several times independently. Foxtail millet was the 'panicum' of the Romans. At present foxtail millet is cultivated all over the world. In tropical Africa it is cultivated to a limited extent in upland areas in East Africa and occasionally recorded elsewhere, e.g. in Cameroon and southern Africa (Malawi, Zimbabwe, Mozambique). In these areas it also occurs as an escape. Foxtail millet is also grown in South Africa and Lesotho. Uses The husked grain of foxtail millet is used as food in Asia, south-eastern Europe and Africa. It is most important in China and India. The grain may be cooked and eaten like rice, either entire or broken. It can be ground and made into unleavened bread or, when mixed with wheat flour, into leavened bread. The flour is also made into cakes, porridges and puddings. In northern China foxtail millet forms part of the staple diet; it is usually mixed with pulses and cooked, or the flour is mixed with that of other cereals in the preparation of bread and noodles. It is considered a nutritious food and is often recommended for the elderly and for pregnant women. Since the 1990s it has been used in China for the industrial preparation of mini crisp chips, millet crisp rolls and flour for baby foods. Foxtail millet is used in the preparation of beer and alcohol,

161 SETARIA 163 especially in Russia and Myanmar, and for vinegar and wine in China. Sprouted seeds are eaten as a vegetable, e.g. in China. In Europe and the United States foxtail millet is primarily grown as bird feed. It is an important fodder crop ('moha'); in the United States and Europe it is grown for hay and silage, and in China the straw is an important fodder. The straw is also used for thatching and bedding, e.g. in India. The bran serves as animal feed and can be used for oil extraction. Foxtail millet is credited with diuretic, astringent and emollient properties and is used to treat rheumatism. It can be sown in contour strips for erosion control. Production and international trade Production statistics for foxtail millet are scarce because they are usually lumped with those of other millets. The annual world production of foxtail millet in the early 1990s was estimated at 5 million t (18% of total millet production), with China being the main producer. In tropical Africa the production of foxtail millet is much lower than that of pearl millet (Pennisetum glaucum (L.) R.Br.) and finger millet (Eleusine coracana (L.) Gaertn.), but no statistics are available. In India and China foxtail millet is mainly grown for home consumption. Properties The composition of foxtail millet grain per 100 g edible portion is: water 12 g, energy 1470 kj (351 kcal), protein 11.2 g, fat 4.0 g, carbohydrate 63.2 g, crude fibre 6.7 g, Ca 31 mg, Fe 2.8 mg, thiamin 0.6 mg, riboflavin 0.1 mg and niacin 3.2 mg (FAO, 1995). The essential amino-acid composition per 100 g grain is: tryptophan 103 mg, lysine 233 mg, methionine 296 mg, phenylalanine 708 mg, threonine 328 mg, valine 728 mg, leucine 1764 mg and isoleucine 803 mg (FAO, 1970). The starch granules are spherical, angular or polyhedral with a diameter of 6-17 im. Most foxtail cultivars are non-glutinous and are thus suitable for the diet of people with coeliac disease. The bran contains about 9% oil. Description Erect annual grass up to 150(- 175) cm tall, tufted, often variously tinged with purple; root system dense, with thin wiry adventitious roots; stem erect, tillering at base, sometimes branched. Leaves alternate, simple; leaf sheath 10-15(-25) cm long, glabrous or slightly hairy; ligule short, fimbriate; blade linear, 15-30(-50) cm x (-4) cm, acuminate at apex, midrib prominent, slightly rough. Inflorescence a spike-like panicle 5 30 cm x 1-2(-5) cm, erect or pendulous, continuous or interrupted at base; rachis ribbed and hairy; lateral branches short, bearing 6-12 spikelets. Spikelets almost sessile, subtended by 1-3 bristles up to 1.5 cm long, elliptical, usually about half as long as the bristles, 2-flowered; lower glume small and 3-veined, upper glume slightly shorter than spikelet, 5-veined; lower floret sterile, upper one bisexual with 5-veined lemma and palea, 2 lodicules, 3 stamens and superior ovary with 2 plumose stigmas. Fruit a caryopsis (grain), broadly ovoid, up to 2 mm long, pale yellow to orange, red, brown or black, tightly enclosed by lemma and palea. Other botanical information Setaria comprises about 100 species distributed in the tropics, subtropics and temperate regions. Foxtail millet is the most economically valuable species of the genus. Several wild Setaria species are harvested for their seeds, e.g. Setaria finita Launert in Namibia. Setaria sphacelata (Schumach.) Stapf & C.E.Hubb. ex M.B.Moss is cultivated as a forage throughout the tropics and its grains are gathered as a famine food in Africa. The grains of Setaria pumila (Poir.) Roem. & Schult, are also eaten as a famine food, e.g. in Mali, Burkina Faso, Sudan and Ethiopia, but it is more important as a forage. Setaria verticillata (L.) P.Beauv. is a forage plant, but also collected as a famine food, e.g. Setaria italica - 1, upper part of plant; 2, sheath mouth with ligule; 3, flowering spikelet with bristles; 4, fruiting spikelet. Source: PROSEA

162 164 CEREALS AND PULSES in Niger, Sudan and Namibia. Setaria italica is a 'crop-weed complex', i.e. with wild and cultivated types. These types show no crossing barriers and isozyme analysis and molecular studies have confirmed their similarity. The wild types are considered to represent Setaria viridis (green foxtail millet), the cultivated ones Setaria italica (foxtail millet). Green foxtail millet occurs worldwide as a variable, annual weed, especially common in temperate regions. It differs from foxtail millet in its completely caducous spikelets, upper glume about as long as the spikelet and more roughly papillose lemma. It is sometimes considered a subspecies of Setaria italica: subsp. viridis (L.) Thell. It is also known as green bristle grass, and is one of the world's most noxious weeds, but it is sometimes used as fodder or for medicinal purposes. Foxtail millet is very variable and numerous cultivars exist, differing in time to maturity, plant height, size, habit and structure of inflorescence, number, colour and length of bristles, and colour of grain. Primitive cultivars have numerous, strongly branched stems (like green foxtail millet), while advanced cultivars produce a single stem with a large, solitary inflorescence. Growth and development Foxtail millet generally starts flowering at about 60 days after sowing, and flowering lasts for days. Flowering proceeds from the top of the panicle downward. The flowers open late at night or early in the morning, and close soon after opening. Foxtail millet is largely selfpollinating with an average outcrossing rate of 4%; natural hybrids between wild and cultivated types occur. Total crop duration is days, although some cultivars only need 60 days to mature. Foxtail millet has largely lost the ability of natural seed dispersal, and shows a tendency toward uniform plant maturity. Foxtail millet follows the C4-cycle photosynthetic pathway. Ecology Foxtail millet is primarily a crop of subtropical and temperate regions; in the tropics it is grown up to 2000(-3300) m altitude. It does not tolerate frost. In China and India it is mainly grown in areas with an annual rainfall of mm. Foxtail millet is not particularly drought-resistant, but its short crop cycle makes it suitable for low-rainfall areas and it can be grown in semi-arid regions with rainfall less than 125 mm in the 3-4 months of growth. It is, however, susceptible to long periods of drought. Flowering is normally accelerated by short days, but day-neutral cultivars exist. Foxtail millet prefers fertile soils with a ph of about 6.5, but can be grown successfully on a wide range of soils, from light sands to heavy clays, and even yields reasonably well on poor or marginal soils. It does not tolerate waterlogging. Propagation and planting Foxtail millet is propagated by seed. The 1000-seed weight is about 2 g. Dormancy is common in freshly harvested seed. The recommended seed rate for sole cropping in Kenya is 4 kg/ha, with a distance of 30 cm between rows and 10 cm within the row. In China and India it is sown at a seed rate of 5-15 kg/ha when grown in pure stands, with plant densities of 300, million plants/ha. It is either broadcast or drilled in rows cm apart, with 5-20 cm within the row, and thinning may be practised. The usual sowing depth is 3-6 cm and a fine, firm seedbed is required. Foxtail millet is grown as a sole crop or intercropped, e.g. with finger millet, cotton, sorghum or pigeon pea in India. Management In Kenya the first weeding of foxtail millet is recommended at 2-3 weeks after emergence of the seedlings, and the second one 2 weeks later. In India foxtail millet is usually weeded once at about 3 weeks after sowing. Foxtail millet responds well to manuring, but generally only irrigated crops are manured. It is usually grown as a rainfed crop, but it may also be grown under irrigation, e.g. in India. Crop rotation of foxtail millet with finger millet and sorghum is common in India. Sometimes it is grown as a catch crop when paddy rice has failed. Diseases and pests The most serious diseases of foxtail millet are blast {Pyricularia setariae), downy mildew (Sclerospora graminicola), leaf rust (Uromyces setariae-italiae) and smut (Ustilago crameri). Downy mildew and smut can be controlled by treating the seed. Important insect pests of foxtail millet are shoot flies (Atherigona spp.), crickets, borers and caterpillars. Foxtail millet is highly susceptible to bird attack in the field, and mice and rats also damage the crop. In stored grain, seed smut (Sorosporium bullatum) and kernel smut (Ustilago paradoxa) may cause considerable losses in addition to the common cereal storage insects. Harvesting Foxtail millet is harvested manually by cutting off the panicles and threshing them. Mechanical harvesting with a combine or binder is possible. In southern In-

163 SORGHUM 165 dia whole plants may be cut and threshed by trampling by cattle or by passing a stone roller over the plants. When grown for fodder, foxtail millet should be harvested before flowering. Yield The average annual yield of rainfed foxtail millet is kg/ha of grain and 2500 kg/ha of straw. Improved cultivars in China yield 1800 kg/ha of grain in regions with less than 900 mm annual rainfall. Much higher grain yields can be obtained with irrigation (in China experimental yields have reached 11 t/ha). As forage it may yield t green matter per ha or 3.5 t hay. Handling after harvest Foxtail millet should be dried thoroughly before storage. The grain is usually husked just before processing because husked grains are readily infested with insects. Husking can be done with a stone roller or with rice milling machinery. In China mini crisp chips are made by cooking husked grains, pressing the product to 1 mm thickness, drying, frying in oil and flavouring. Crispy rolls are prepared from husked grains which are soaked in water, ground and, after addition of sugar, toasted between 2 iron plates and formed into rolls. Genetic resources Large collections of foxtail millet germplasm are kept by the Institute of Crop Germplasm Resources (CAAS), Beijing, China (25,380 accessions), the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India (1528 accessions) and the All India Coordinated Minor Millet Project, University of Agricultural Sciences, Bangalore, India (1300 accessions). In Africa a collection of 451 foxtail millet accessions is kept at the National Dryland Farming Research Station, Machakos, Kenya. Resistance to blast and rust has been identified in germplasm collections. Breeding Foxtail millet breeding is mainly carried out in China and India. Major breeding objectives are developing high-yielding cultivars which produce protein-rich seed and are resistant to diseases, pests and lodging, and adapted to local ecological circumstances. In China, for example, cultivars with a short growing cycle and a high drought and cold tolerance have been developed; these can be grown in the summer season after winter wheat. The recommended cultivar in Kenya is 'KAT/FOX-1'; it matures in 3-4 months. Techniques applied in foxtail millet breeding include selection, hybridization (using malesterile lines) and radiation-induced mutations. Due to the floral morphology (very small flowers) and flowering behaviour of foxtail millet, artificial cross-pollination is difficult, but an effective procedure for artificial hybridization of foxtail millet has been developed in the United States. High levels of heterosis for grain yield (67%) and panicle length (68%) have been found. Prospects On a worldwide scale foxtail millet has lost its importance as a food crop in competition with major cereals such as wheat, rice, maize and sorghum. However, because of its short crop cycle and the fact that it can be grown on a wide range of soil types it may remain a useful crop in Asia on poor agricultural land in regions with low rainfall or a short growing season. The prospects for foxtail millet in tropical Africa seem limited, but it may gain importance as a niche crop in dry regions at medium to high altitudes. Major references de Wet, Oestry-Stidd & Cubero, 1979; FAO, undated; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Oduori, 1993; Prasada Rao & de Wet, 1997; Prasada Rao et al., 1987; Purseglove, 1972; Rahayu & Jansen, 1996; Riley et al. (Editors), 1993; Seetharam, Riley & Harinarayana, Other references Benabdelmouna et al., 2001; Benabdelmouna, Abirached-Darmency & Darmency, 2001; Burkill, 1994; Clayton, 1989; CSIR, 1972; de Wet, 1995b; FAO, 1970; FAO, 1995; Gibbs Russell et al., 1990; Hülse, Laing & Pearson, 1980; ICRISAT & FAO, 1996; Klaassen & Craven, 2003; le Thierry d'ennequin et al, 2000; Li et al., 1998; Malm & Rachie, 1971; Ministry of Agriculture and Rural Development, 2002; Petr et al., 2003; Siles, Baltensperger & Nelson, 2001; Siles et al., 2004; Wanous, Sources of illustration Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Rahayu & Jansen, Authors M. Brink Based on PROSEA 10: Cereals. SORGHUM BICOLOR (L.) Moench Protologue Methodus: 207 (1794). Family Poaceae (Gramineae) Chromosome number 2n = 20 Vernacular names Sorghum, sorgo, guinea corn, great millet, durra (En). Sorgho, gros mil, sorgho rouge (dye cultivars), sorgho des teinturiers (dye cultivars) (Fr). Sorgo, milho miudo, massambala (Po). Mtama (Sw).

164 166 CEREALS AND PULSES Sorghum bicolour - planted Origin and geographic distribution The greatest diversity in both cultivated and wild types of Sorghum is found in north-eastern tropical Africa. The crop may have been domesticated in that region, possibly Ethiopia. Various hypotheses have been put forward as to when the crop was domesticated, from as early as BC to around 1000 BC, but the latter period is more widely accepted now. From north-eastern Africa sorghum was distributed all over Africa and along shipping and trade routes through the Middle East to India. From India it is believed to have been carried to China along the silk route and through coastal shipping to South-East Asia. From West Africa sorghum was taken to the Americas through the slave trade. It was introduced into the United States for commercial cultivation from North Africa, South Africa and India at the end of the 19 th century. It was subsequently introduced into South America and Australia. It is now widely cultivated in drier areas of Africa, Asia, the Americas, Europe and Australia between latitudes of up to 50 N in North America and Russia and 40 S in Argentina. Sorghum types exclusively cultivated for the dye in the leaf sheaths can be found from Senegal to Sudan. Uses Sorghum is an important staple food, particularly in semi-arid tropical regions of Africa and Asia, and an important feed grain and fodder crop in the Americas and Australia. In the simplest food preparations, the whole grain is boiled (to produce a food resembling rice), roasted (usually at the dough stage), or popped (like maize). More often the grain is ground or pounded into flour, often after hulling. Sorghum flour is used to make thick or thin porridge, pancake, dumplings or couscous, opaque and cloudy beers and non-alcoholic fermented beverages. In Africa sorghum grain is germinated, dried and ground to form malt, which is used as a substratum for fermentation in local beer production. White grain is generally preferred for cooking while red and brown grains are normally used for beer making. Where bird pressure is high, e.g. around Lake Victoria, red and brown types rich in tannin may be grown for food instead of white types. In China sorghum is extensively distilled to make a popular spirit and vinegar. Sorghum grain is a significant component of cattle, pig and chicken feeds in the United States, Central and South America, Australia and China, and is becoming important in chicken feed in India. It requires grinding, rolling, flaking or steaming to maximize its nutritional value. Several non-edible sorghum cultivars are exclusively grown for the red dye present in the leaf sheaths and sometimes also in adjacent stem parts. In Africa this dye is used particularly for goat-skin leather (e.g. in Nigeria), but also for mats, textiles, strips of palm leaves and grasses used in basketry and weaving, ornamental calabashes, wool (e.g. in Sudan), as a body paint and to colour cheese and lickstones for cattle (e.g. in Benin). A similar dye can be extracted from the grain refuse (glumes and grain wall) of several red sorghum cultivars grown for food or for beer-making. In Nigeria the red sorghum dyes were traditionally used by the Bunu, Aworo, Igbira and Okpella people for a fabric called 'abata', used as a funeral hanging, decorated with patterns made by thick threads added to the weft of the fabric. The fabrics in which the dominant colours were derived from sorghum were known as 'ifala'. Sorghum is also used to provide the violet colours decorating the masks worn during certain dances by Yoruba people in southern Benin and in south-western Nigeria. In Côte d'ivoire sorghum and other tannin-rich dyes are used in combination with mud to create the patterns of the painted cloths produced in the Korhogo region. The dye was formerly exported to Morocco where it was used in the leather industry. In China sorghum types with red panicles and leaf sheaths were also used for dyeing. In the 19 th century red sorghums were exported to Europe where the dye was known as 'carmin de sorgho'. It was extracted by squeezing out the juice, which was then fermented. Used with wool or silk mordanted with tin or chrome, the

165 SORGHUM 167 result was a colourfast red-brown that was once known as 'rouge badois'. 'Durra red', a similar product, was imported from India into the United Kingdom where the dye was known as 'Hansen brown' or 'Meyer brown'. Recently the use of sorghum dye in hair dying products has been patented. The stems of sweet sorghum types are chewed like sugar cane and, mainly in the United States, a sweet syrup is pressed from them. In North America and eastern Europe special types with very long, fibrous and few-seeded inflorescences, known as 'broomcorn', are grown to make brooms. Sorghum plant residues are used extensively as material for roofing, fencing, weaving and as fuel. The stems can be used for the production of fibre board. Danish scientists have made good panelling using stem chips of sorghum. The stover remaining after harvesting the grain is cut and fed to cattle, sheep and goats, or may be grazed. Some farmers grind harvested stover and mix it with sorghum bran or salt to feed livestock. Sorghum is also grown for forage, either for direct feeding to ruminants or for preservation as hay or silage. Sorghum flour is used to produce an adhesive in the manufacture of plywood. Sweet sorghum is suitable for the production of alcohol, while the bagasse is a suitable source of paper pulp for the production of kraft paper, newsprint and fibre board. Sorghum has various applications in African traditional medicine: seed extracts are drunk to treat hepatitis, and decoctions of twigs with lemon against jaundice; leaves and panicles are included in plant mixtures for decoctions against anaemia. The Salka people in northern Nigeria use sorghum in arrow-poisons. The red pigment is said to have antimicrobial and antifungal properties and is also used as a cure for anaemia in traditional medicine. Production and international trade Sorghum grain is the fifth most important cereal in the world after wheat, rice, maize and barley. In Africa it comes second after maize in terms of production. According to FAO estimates, the average world production of sorghum grain in amounted to 57.7 million t/year from 42.6 million ha. The production in sub-saharan Africa was 19.0 million t/year from 22.8 million ha. The main producing countries are the United States (12.0 million t/year in from 3.2 million ha), India (7.6 million t/year from 9.8 million ha), Nigeria (7.6 million t/year from 6.9 million ha), Mexico (6.0 million t/year from 1.9 million ha), Sudan (3.4 million t/year from 5.3 million ha), Argentina (3.0 million t/year from 630,000 ha), China (3.0million t/year from 840,000 ha), Australia (1.9 million t/year from 690,000 ha), Ethiopia (1.4 million t/year from 1.2 million ha) and Burkina Faso (1.3 million t/year from 1.4 million ha). In sub-saharan Africa annual production increased from around 10 million t from 13 million ha in the early 1960s to about 20 million t from 25 million ha in the early 2000s. Almost all sorghum traded on international markets is for use as livestock feed. Average world exports of sorghum in amounted to 6.3 million t/year, almost all from the United States (5.6 million t/year). The main importers are Mexico and Japan. In tropical Africa most sorghum is grown for home consumption (except for beer production). In southern and eastern Africa malting sorghum for beer brewing has developed into a large-scale commercial industry, using about 150,000 t of sorghum grain annually. In Uganda commercial production of lager beer using sorghum instead of barley is becoming a great success (annual requirement of sorghum is 3000 t) and is very promising for other African countries. In Nigeria sorghum malting has become a major industry for lager and stout beer brewing and for malt beverages, using about 15,000 t of sorghum annually. In South Africa an instant breakfast cereal is made from sorghum that is similar in quality but much cheaper than wheat or maize products. Annual production is 12,000 t and is increasing steadiiy. In West Africa small tied bundles of 4-6 leaf sheaths of sorghum dye cultivars are offered for sale on local markets (in the 1990s the price was about 150 CFA). In 1993 in Burkina Faso, the red pigment was successfully extracted chemically from sorghum leaf sheaths and offered for sale as dry powder on the world market. Properties The composition of sorghum grain per 100 g edible portion is: water 9.2 g, energy 1418 kj (339 kcal), protein 11.3 g, fat 3.3 g, carbohydrate 74.6 g, Ca 28 mg, P 287 mg, Fe 4.4 mg, vitamin A 0 IU, thiamin 0.24 mg, riboflavin 0.14 mg, niacin 2.9 mg and ascorbic acid 0 mg. The essential amino acid composition per 100 g edible portion is: tryptophan 124 mg, lysine 229 mg, methionine 169 mg, phenylalanine 546 mg, threonine 346 mg, valine 561 mg, leucine 1491 mg and isoleucine 433 mg. The principal fatty acids are per 100 g

166 168 CEKEALS AND PULSES edible portion: linoleic acid 1305 mg, oleic acid 964 mg and palmitic acid 407 mg (USDA, 2004). Sorghum grain is first limiting in lysine, then in methionine and threonine. Much of the protein in sorghum is prolamine (39-73%), which is poorly digestible. As a result, maximum available protein in sorghum grain is usually 8-9%. The tannin content of sorghum also affects its nutritional value. High- and low-tannin sorghum types are distinguished. High-tannin sorghum types (sometimes called 'brown sorghums', although the grain may also be white, yellow or red) have less nutritional value but have agronomic advantages, including resistance to birds, insects, fungi and decreased sprouting in the panicle. Sorghum types without a pigmented grain wall ('white sorghums') do not contain condensed tannins and have a nutritional value similar to that of maize. Decortication, parboiling, malting or steeping in alkali solutions significantly reduce the tannin content of sorghum grain. In general the endosperm accounts for 82 84% of the grain weight, the germ for 9-10% and the grain wall for 6-8%. The starch granules in the endosperm have a diameter of (4-)15(-25) im. The starch normally contains 70-80% amylopectin and 20-30% amylose, although some types contain 100% amylopectin and others up to 62% amylose. The gelatinization temperature ranges from C. Sorghum grain does not contain gluten and cannot be used for leavened products unless mixed with wheat. The composition of the green plant varies according to age and cultivar but it normally contains g of water per 100 g of fresh material. On a dry basis it contains per 100 g: protein 12 g, carbohydrate g and fibre g. The glycoside dhurrin occurs in the aerial parts of most sorghum. Dhurrin is hydrolyzed to hydrocyanic acid (HCN), which is highly toxic and can kill grazing animals. It is particularly concentrated in the young leaves and tillers and in plants that are suffering from drought. HCN content usually declines with age, reaching non-toxic levels days after planting, and HCN is destroyed when the fodder is made into hay or silage. The red pigment in sorghum dye cultivars is composed of anthocyanic compounds, particularly rich (95%) in the stable apigeninidin chloride (3-deoxyanthocyanidin) and tannins of the condensed proanthocyanidins group (producing phlobaphen reds). The red pigment in the sorghum leaf sheath makes up to over 20% of the dry weight. The role of the non-pathogenic fungus Bipolaris maydis in the production of apigeninidin in these cultivars deserves further research. Used without a mordant, the dye obtained from sorghum gives a dark red that is fairly colourfast and still much used in eastern Africa, particularly Sudan and Ethiopia, for dyeing leather, cotton and the grasses and reeds used for woven matting. Black colours are obtained with natron salt and iron mordants. From red sorghum grain the pigments apigenin, quercimeritrin, kaempferol glucosides, apigenidin glucosides, apigeninidin, luteolinidin and 7-O-methyl-luteolin-glucoside have been isolated. From the stem of red sorghum cultivars the constituents of the red dye were the anthocyanidin apigeninidin (17%) and the flavonoids luteolin (9%) and apigenin (4%). The anaemia curing property of the red pigment has been confirmed in tests with rats. Description Annual grass up to 5 m tall, with one to many tillers, originating from the base or stem nodes; roots concentrated in the top 90 cm of the soil but sometimes extending to twice that depth, spreading laterally up to 1.5 m; stem (culm) solid, usually erect. Leaves alternate, simple; leaf sheath cm long, often with a waxy bloom, with band of short white hairs at base near attachment, reddish in dye cultivars, auricled; ligule short, c. 2 mm long, ciliate on upper free edge; blade lanceolate to linear-lanceolate, cm x cm, initially erect, later curving, margins flat or wavy. Inflorescence a terminal panicle up to 60 cm long; rachis short or long, with primary, secondary and sometimes tertiary branches, with spikelets in pairs and in groups of three at the ends of branches. Spikelet sessile and bisexual or pedicelled and male or sterile, with 2 florets; sessile spikelet 3-10 mm long, with glumes approximately equal in length, lower glume 6-18-veined, usually with a coarse keellike vein on each side, upper glume usually narrower and more pointed, with central keel for part of its length, lower floret consisting of a lemma only, upper floret bisexual, with lemma cleft at apex, with or without kneed and twisted awn, palea, when present, small and thin, lodicules 2, stamens 3; ovary superior, 1- celled with 2 long styles ending in feathery stigmas; pedicelled spikelet persistent or deciduous, smaller and narrower than sessile spikelet, often consisting of only two glumes, sometimes with lower floret consisting of lemma only and upper floret with lemma, 2 lodicules and 3 stamens. Fruit a caryopsis (grain), usually partially covered by glumes, 4

167 SORGHUM 169 Sorghum bicolor - panicles and spikelets of the 5 basic races: 1, bicolor; 2, caudatum; 3, durra; 4, guinea; 5, kafir. Source: PROSEA 8 mm in diameter, rounded and bluntly pointed. Other botanical information Sorghum comprises species. Sorghum bicolor belongs to section Sorghum, together with the 2 perennial species Sorghum halepense (L.) Pers. and Sorghum propinquum (Kunth) Hitchc. At present, Sorghum bicolor is mostly considered as an extremely variable crop-weed complex, comprising wild, weedy and cultivated annual types (classified as subspecies) which are fully interfertile. The cultivated types are classified as subsp. bicolor (synonyms: Sorghum ankolib Stapf, Sorghum caudatum Stapf, Sorghum cernuum Host, Sorghum dochna (Forssk.) Snowden, Sorghum durra (Forssk.) Stapf, Sorghum membranaceum Chiov., Sorghum nigricans (Ruiz & Pav.) Snowden, Sorghum subglabrescens (Steud.) Schweinf. & Asch., Sorghum vulgare Pers.) and they are subclassified into different races on the basis of grain shape, glume shape and panicle type. Five basic races and hybrid combinations of 2 or more of these races are recognized and grouped into subsp. bicolor. A classification into cultivar groups would, however, be more appropriate. The 5 basic races are: - Bicolor: the most primitive cultivated sorghum, characterized by open inflorescences and long clasping glumes that enclose the usually small grain at maturity. Cultivars are grown in Africa and Asia, some for their sweet stems to make syrup or molasses, others for their bitter grains used to flavour sorghum beer, but they are rarely important. They are frequently found in wet conditions. - Caudatum: characterized by turtle-backed grains that are flat on one side and curved on the other; the panicle shape is variable and the glumes are usually much shorter than the grain. Cultivars are widely grown in north-eastern Nigeria, Chad, Sudan and Uganda. The types used for dyeing also belong here and are known as 'karan dafi' by the Hausa people in Nigeria. - Durra: characterized by compact inflorescences, characteristically flattened sessile spikelets, and creased lower glumes; the grain is often spherical. Cultivars are widely grown along the fringes of the southern Sahara, western Asia and parts of India. The durra type is predominant in Ethiopia and in the Nile valley in Sudan and Egypt. It is the most specialized and highly evolved of all races and many useful genes are found in this type. Durra cultivars range in maturity from long to short-season. Most of them are drought resistant. - Guinea: characterized by usually large, open inflorescences with branches often pendulous at maturity; the grain is typically flattened and twisted obliquely between long gaping glumes at maturity. Guinea sorghum occurs primarily in West Africa, but it is also grown along the East African rift from Malawi to Swaziland and it has also spread to India and the coastal areas of South-East Asia. Many subgroups can be distinguished, e.g. with cultivars especially adapted to high or low rainfall regimes. In the past the grain was often used as ship's provisions because it stored well. - Kafir: characterized by relatively compact panicles that are often cylindrical in shape, elliptical sessile spikelets and tightly clasping glumes that are usually much shorter than the grain. Kafir sorghum is an important staple across the eastern and southern savanna from Tanzania to South Africa. Kafir landraces tend to be insensitive to photoperiod and most commercially important

168 170 CEREALS AND PULSES male-sterile lines are derived from kafir type sorghum. Hybrid races exhibit various combinations and intermediate forms of the characteristics of the 5 basic races. Durra-bicolor is found mainly in Ethiopia, Yemen and India, guinea-caudatum is a major sorghum grown in Nigeria and Sudan, and guinea-kafir is grown in East Africa and India. Kafir-caudatum is widely grown in the United States and almost all of the modern North American hybrid grain cultivars are of this type. Guinea-caudatum with yellow endosperm and large seed size is used in breeding programmes in the United States. The wild representatives are classified as subsp. verticilliflorum (Steud.) Piper (synonyms: Sorghum arundinaceum (Desv.) Stapf, Sorghum bicolor (L.) Moench subsp. arundinaceum (Desv.) de Wet & J.R.Harlan): tufted annual or short-lived perennial, with slender to stout culms up to 4 m tall; leaf blade linearlanceolate, up to 75 cm x 7 cm; panicles usually large, somewhat contracted to loose, up to 60 cm x 25 cm, branches obliquely ascending, spreading or pendulous. Wild types extend across the African savanna and have been introduced into tropical Australia, parts of India and the New World. The weedy plants are usually considered as hybrids between subsp. bicolor and subsp. verticilliflorum, and named subsp. drummondii (Steud.) de Wet (synonyms: Sorghum x-drummondii (Steud.) Millsp. & Chase, Sorghum aterrimum Stapf, Sorghum sudanense (Piper) Stapf); they occur in Africa wherever cultivated sorghum and its wild relatives are sympatric because they cross freely. These weedy plants occur in recently abandoned fields and field margins as a very persistent weed; stem up to 4 m tall; leaf blade lanceolate, up to 50 cm x 6 cm; panicle usually rather contracted, up to 30 cm x 15 cm, often with pendulous branches. A well-known forage grass, 'Sudan grass', belongs to this complex. Growth and development The optimum temperature for sorghum seed germination is C. Seedling emergence takes 3-10 days. Panicle initiation takes place after approximately one third of the growth cycle. By this stage the total number of leaves (7-24) has been determined and about one-third of total leaf area has developed. Rapid leaf development, stem elongation and internode expansion follow panicle initiation. Rapid growth of the panicle also occurs. By the time the flag leaf is visible, all but the final 3 to 4 leaves are fully expanded and light interception is approaching its maximum; lower leaves have begun to senesce. During the boot stage, the developing panicle has almost reached its full size and is clearly visible in the leaf sheath; leaf expansion is complete. The peduncle grows rapidly and the panicle emerges from the leaf sheath. Flowering follows soon after panicle emergence, with the interval largely determined by temperature. Individual panicles start flowering from the tip downwards and flowering may extend over 4-9 days. Sorghum is predominantly self-pollinating; cross-pollination may range from 0-50%, but is on average about 5-6%. Grain filling occurs rapidly between flowering and the soft dough stage, with about half the total dry weight accumulating in this period. Lower leaves continue to senesce and die. By the hard dough stage, grain dry weight has reached about three-quarters of its final level. At physiological maturity, determined by the appearance of a dark layer at the hilum (where the grain is attached to the panicle), maximum dry weight has been achieved. Moisture content of the grain is usually between 25 35% at this stage. The time taken between flowering and maturity depends on environmental conditions but normally represents about one-third of the duration of the crop cycle. Further drying of the grain takes place between physiological maturity and harvest, which usually occurs when grain moisture content has fallen below 20%. Leaves may senesce rapidly or stay green with further growth if conditions are favourable. Early maturing sorghum cultivars take only 100 days or less, whereas longduration sorghum requires 5-7 months. Sorghum follows the C4-cycle photosynthetic pathway. Ecology Sorghum is primarily a plant of hot, semi-arid tropical environments that are too dry for maize. It is particularly adapted to drought due to a number of morphological and physiological characteristics, including an extensive root system, waxy bloom on leaves that reduces water loss, and the ability to stop growth in periods of drought and resume it when the stress is relieved. A rainfall of mm evenly distributed over the cropping season is normally adequate for cultivars maturing in 3-4 months. Sorghum tolerates waterlogging and can also be grown in areas of high rainfall. It tolerates a wide range of temperatures and is also grown widely in temperate regions and at altitudes up to 2300 m in the tropics. The optimum temperature is C,

169 SORGHUM m but temperatures as low as 21"C will not dramatically affect growth and yield. Sterility can occur when night temperatures fall below C during the flowering period. Sorghum is susceptible to frost, but to a lesser extent than maize and light night-frosts during ripening cause little damage. Sorghum is a short-day plant with a wide range of reactions to photoperiod. Some tropical cultivars fail to flower or to set seed at high latitudes. In the United States, Australia and India the existence of mild photoperiod-sensitive to virtually insensitive cultivars has been recorded. Sorghum is well suited to grow on heavy Vertisols commonly found in the tropics, where its tolerance of waterlogging is often required, but is equally suited to light sandy soils. The best growth is achieved on loams and sandy loams. Sorghum tolerates a range of soil ph from and is more tolerant of salinity than maize. It is adapted to poor soils and can produce grain on soils where many other crops would fail. In the floodplains of the Senegal and Niger rivers and in parts of Chad and Cameroon sorghum is sown in the early dry season when the water recedes, and the crop survives on residual moisture ('culture de décrue'). Propagation and planting Sorghum is normally grown from seed. The 1000-grain weight is g. Seed dormancy is not common in cultivated sorghum. A fine seedbed is preferable but is often not achieved. The seed is usually sown directly into a furrow following a plough, but can also be broadcast and harrowed into the soil. Optimum plant spacing depends on soil type and availability of moisture. In low-rainfall areas a population of 20,000 plants/ha is normal, in high-rainfall areas 60,000 plants/ha. For favourable conditions, spacings of cm between rows and cm within the row, resulting in 80, ,000 pockets per ha, are normal; for drier or less fertile conditions rows 1 m apart, or broadcasting at 6 kg seed per ha. A planting depth of cm is common, and up to 25 seeds may be sown per pocket. Occasionally, seedlings are grown in a nursery and transplanted into the field early in the dry season, e.g. on the floodplains round Lake Chad in Africa ('sorgho repiqué'). Sweet sorghum in the United States is also sometimes transplanted. Sorghum can also be propagated vegetatively by splitting tillers from established plants and transplanting them, a practice that is often used by small farmers to fill gaps. Sorghum may be harvested more than once as a ratoon crop, e.g. in locations with a bimodal rainfall pattern. Sorghum is often grown in intercropping systems with maize, pearl millet, cowpea, common bean, groundnut and bambara groundnut; in India also with pigeonpea. Dye cultivars are never grown in large quantities. Farmers usually grow a few plants in or around their normal sorghum field or near the house. Management Sorghum does not compete well with weeds during the early stages of growth, and it is recommended that weeding be done early during the seedling stage. In tropical Africa weeding is commonly done once or twice with a hoe but sometimes animal-drawn or tractor-drawn cultivators are used. Where couch grass (Cynodon dactylon (L.) Pers.) is a problem more frequent weeding is necessary. Sorghum may be weeded by a combination of inter-row cultivation with animal-drawn implements and hand weeding within rows. Chemical weed control is almost non-existent among small farmers. Thinning can be carried out at the same time as hand weeding, or at intervals during the crop cycle, particularly where thinnings are used to feed livestock. Subsistence farmers rarely apply fertilizer, but application of farmyard manure or ash is common. In South Africa and the United States high doses of fertilizers are used in the production of sorghum. In tropical Africa sorghum is grown mainly as a rainfed crop, but it is grown under irrigation in Sudan. It is grown in rotations with maize, pearl millet, finger millet, cotton and other crops. It is often planted late in the rotation, as it tolerates low soil fertility. Under certain conditions decomposing roots of sorghum have an allelopathic effect on the subsequent crop, including sorghum. Diseases and pests Common seed and seedling rot diseases in sorghum are caused by soil- and seed-borne Aspergillus, Fusarium, Pythium, Rhizoctonia and Rhizopus spp. They are controlled by treatment of the seed with fungicides. Anthracnose (Colletotrichum graminicola) is common in hot and humid parts of Africa. Control measures include the use of resistant cultivars and crop rotation. Downy mildew (Peronosclerospora sorghi) may cause serious yield losses; the use of resistant cultivars and seed treatment are recommended. Smuts (Sporisorium spp.) are important panicle diseases. Loose and covered kernel smut are controlled by seed treatment with fungicides; head smut and long smut by using resistant

170 172 CEREALS AND PULSES cultivars and cultural practices such as crop rotation and removal of infected panicles. Grain mould is caused by a complex of fungal pathogens (predominantly Cochliobolus lunatus (synonym: Curvularia lunata), Fusarium spp. and Phoma sorghina) that infect the grain during development and can lead to severe discoloration and loss of quality. It is most severe in seasons when rains continue through the grain maturity stage and delay the harvest. Control measures include adjustment of the sowing date to avoid maturation during wet weather, and the use of resistant cultivars. Important pests of sorghum in tropical Africa are shoot fly (Atherigona soccata) and stem borers (particularly Busseola fusca, Chilo partellus and Sesamia calamistis). Shoot fly larvae attack shoots of seedlings and tillers, and cause 'dead hearts'. Stem borers cause damage in all crop stages. Damage by both shoot fly and stem borers can be reduced by early, non-staggered planting and seed or soil treatment with insecticides. Resistance to shoot fly is associated with low yield. Foliage pests include army worms (Spodoptera and Mythimna spp.); they are controlled by contact insecticides. Larvae of the sorghum midge (Stenodiplosis sorghicola, synonym: Contarinia sorghicola) feed on the young grains in the panicle. Damage can be limited by sowing early-maturing cultivars and avoiding staggered planting. Head bugs (Eurystylus and Calocoris spp.) suck on developing grains, resulting in yield loss, grain deformation and discoloration and infection by moulds. Guinea type sorghum is generally less affected. In practice, control methods of diseases and pests are mainly preventative or cultural, including selection of optimum planting dates, seed treatment and crop rotation. Early sowing is particularly important as a mechanism to avoid large insect populations at times when plants are most susceptible to damage. High levels of host plant resistance are available for sorghum midge, but only low levels of resistance for the other pests. Chemical control of diseases and insect pests is rarely practised in tropical Africa. Birds, especially Quelea quelea, cause important yield losses. Control measures include the choice of suitable planting dates, timely harvesting, bird scaring and the destruction of roosting and nesting sites. Brown sorghum is less preferred by birds than the tannin-free white sorghum. Sorghum is very susceptible to damage by storage pests, the main ones being rice weevil (Sitophilus oryzae), flour beetle (Tribolium castaneum) and the grain moth (Sitotroga cerealella). Damage can be minimized by drying grain adequately before storage. Cultivars with hard grain also suffer less damage. The parasitic weed Striga (especially Striga hermonthica (Del.) Benth., but also Striga asiatica (L.) Kuntze, Striga densiflora Benth. and Striga forbesii Benth.) has become a major constraint to sorghum cultivation, particularly in Africa, where severe infestations can lead to grain losses of 100% and land being abandoned. Striga can be controlled by cultural methods such as rotation with trap crops or with crops that are not susceptible (e.g. groundnut, cotton or sunflower), rigorous removal of the weeds before flowering and application of nitrogen fertilizer and herbicides. A few sorghum cultivars that are resistant or tolerant to Striga have been identified. Harvesting Sorghum is usually harvested when the grain moisture content has fallen below 20%, and the grain has become hard. Harvesting is done by hand using a knife to cut the panicles, which are temporarily stored in sacks before being taken to the threshing floor for further drying to a moisture content of 12 13%. Alternatively, the whole plant is cut or pulled up and the panicle removed later. Combine harvesting is possible, but many small farmers cannot afford to buy the machinery. In South Africa combine harvesting is more common. For dye production, leaf sheaths are harvested when the plant comes to maturity, about 4-6 months after sowing. They can be used immediately or dried and stored. Rainfed forage sorghum is usually cut only once, soon after flowering. Forage sorghum crops grown under more favourable conditions, often with irrigation and high levels of fertilizer, can be harvested and then left to regrow (ratoon). Broomcorn is harvested by hand as mechanical harvesters are not available. Sweet sorghum is harvested when the seed is in the soft dough stage when the sugar content of the stalk is highest. Yield Average sorghum grain yields on farmers' fields in Africa are as low as t/ha because sorghum is often grown in marginal areas under traditional farming practices (low inputs, traditional landraces). Under favourable conditions sorghum can produce grain yields up to 13 t/ha. In South Africa, with intensive agricultural practices and improved

171 SORGHUM 173 cultivars, average commercial yield was 2.3 t/ha in In China, where sorghum is grown with high levels of inputs, yield averages 3.6 t/ha and in the United States 3.8 t/ha. Forage yields from single-cut cultivars and hybrids can reach 20 t/ha of dry matter. Multicut cultivars and hybrids usually give only slightly higher total yields but produce better quality forage. Sweet sorghum yields about syrup per ha in the United States. Average broomcorn yields are kg/ha, enough to make brooms. Handling after harvest The harvested grain of sorghum is usually sun-dried, often in the panicle. Panicles, particularly those to be retained for seed, may be stored hanging from the ceiling of kitchens over cooking fires where the smoke helps to deter insect attack. Alternatively, the heads may be threshed after drying and the grain stored in granaries, above or below ground, designed to prevent insect attack. Traditional food preparation of sorghum is quite varied. The whole grain may be ground into flour or decorticated before grinding to either a fine particle product or flour which is then used in various food products. To prepare porridge, water is boiled and sorghum flour is gradually added until the desired consistency of the paste is reached. Regular stirring is needed to mix the contents thoroughly. Another simple form of sorghum food preparation is to boil the grain before or after decorticating. To make beer, sorghum grain is germinated, dried, pounded into flour and mixed with water and left to ferment in a warm place for some days. To make the non-fermented drink 'mageu' in Botswana and South Africa, milled sorghum malt is mixed with water and kept at room temperature for 2-3 days. Occasional stirring may be necessary. In a traditional method of dyeing hides with sorghum dye in West Africa, a watery extract of wood ashes, preferably from the wood of Anogeissus leiocarpa (DC.) Guill. & Perr., is prepared and allowed to stand for 3-4 hours. The major active compound of the lye is potassium- or sodium carbonate. The red leaf sheaths are pulverized and placed in a large vessel in which the dyeing is carried out. From time to time a little lye is added and diluted with plain water as desired, obtaining a crimson liquid. The tanned hide that has been dressed with oil is folded with the tanned side outwards, the hide is immersed for about two minutes in the dye bath, wrung out and shaken. Alternatively, the dye liquid is painted on the tanned surface with the fingers or a brush. The hide is then rinsed in cold water acidulated with lime juice or tamarind pulp. After the hide has been dried, the process is completed by rubbing the hide with a smooth stone on a wooden block. It is estimated that of dye bath is sufficient for about 6 skins of medium size. Another recipe uses about 30 leaf-sheaths of sorghum, about half a spoonful of soda, a handful of 'sant' pods (Acacia nilotica (L.) Willd. ex Delile) or 2 handfuls of chips of mangrove bark, 2 spoonfuls of palm oil and of water. These are all mixed together and boiled, the juice of 5 or 6 limes added, and the liquid is left to simmer for 2 hours. It is then ready for application on the skin by brushing or rubbing. To obtain a dye of constant high quality, a laboratory extraction technique has been designed in Burkina Faso. Sorghum leaf sheaths are crushed into fine particles, a solvent is added in an acid or basic medium (both give similar results) and a red liquid is produced. By addition of an acid the dyestuff is precipitated and is centrifuged off. The end product is a fine, burgundy-red powder with an apigeninidin concentration of 50-60%, ready for use as a dye. Pure apigeninidin can be obtained by further processing of the powder. Forage sorghum can be fed to livestock while still green or can be stored in various ways for later use. The forage is often dried and stacked or can be made into silage. Stover left after harvest of grain is often grazed by animals. Genetic resources A major collection of sorghum germplasm is maintained and distributed to interested researchers by the International Crops Research Institute for the Semi- Arid Tropics (ICRISAT), Patancheru, India. The collection extends to over 36,000 accessions from all the major sorghum-growing regions of the world (90 countries). Large germplasm collections of sorghum are also held in the United States (Southern Regional Plant Introduction Station, Griffin, Georgia, 30,100 accessions; National Seed Storage Laboratory, Fort Collins, Colorado, 10,500 accessions) and China (Institute of Crop Germplasm Resources (CAAS), Beijing, 15,300 accessions). In tropical Africa large germplasm collections of sorghum are held in Zimbabwe (SADC/ICRISAT Sorghum and Millet Improvement Program, Matopos, 12,340 accessions), Ethiopia (Institute of Biodiversity Conservation (IBC), Addis Ababa, 7260 accessions), Kenya (National Genebank of

172 174 CEREALS AND PULSES Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 3410 accessions) and Uganda (Serere Agricultural and Animal Production Research Institute, Serere, 2635 accessions). Breeding The main objectives in sorghum breeding include high grain yield, white grain for human consumption with improved nutritional value and processing quality, and red or brown grain for feed purposes and brewing. In many countries the emphasis is on producing cultivars which combine high grain yield with high stover yields because of the importance of the residues as animal feed. Incorporation of resistance to major yield-limiting diseases and pests, and tolerance of abiotic stresses are also of high priority. Resistance to grain moulds and other diseases as well as to insect pests such as head bugs and sorghum midge has been identified. High-yielding improved cultivars of sorghum are available in most of the main producing countries. These include cultivars and hybrids produced using cytoplasmic male sterility. Compared to traditional landraces they have a weak photoperiodic response and they are less hardy, less tall, with a lower grain quality but a higher yield potential. Striga-resistant cultivars have been released in Africa and India, e.g. 'Framida' in Ghana and Burkina Faso. Cultivars resistant to grain mould have also been released. Special cultivars with high biomass production and good forage quality are bred for animal feed. Modern sorghum cultivars predominate in the Americas, China and Australia, but in Africa they occupy probably less than 10% of the area under sorghum. In India about 50% of the sorghum area is sown to modern cultivars and 50% to traditional landraces. The sorghum genome is relatively small (about 760 Mbp) compared to that of maize (about 2500 Mbp), and construction of a physical genome map is in progress. Several genetic linkage maps have been developed, mainly based on RFLP markers. Various genes have been tagged, e.g. genes associated with head smut resistance, leaf blight resistance and shattering. Many QTLs have been mapped, including those associated with plant height, tillering, seed size, drought resistance and rust resistance. In-vitro plant regeneration has been achieved from calli derived from young leaf bases, shoot apices, immature inflorescences and immature embryos. Protocols have been developed for the production of stably transformed sorghum plants using microprojectile bombardment or Agrobacterium-mediated transformation, but the efficiency is generally low, especially with the former technique. Prospects Sorghum is a hardy, droughttolerant crop with a high potential yield, which plays an important role in tropical Africa and elsewhere, especially as source of food and fodder, but also for a range of other uses, including as a source of dye. Sorghum has lost part of its traditional area in tropical Africa to maize, which yields better in more favourable environments, is less liable to bird damage and easier to process. It is to be expected, however, that sorghum will remain an important food security crop in less favourable environments in tropical Africa. Important problems in sorghum cultivation to be addressed by research and breeding activities are the large yield losses caused by parasitic weeds (especially Striga hermonthica), anthracnose, downy mildew, grain moulds, sorghum midge and stem borers. Improved sorghum cultivars are not widely grown in tropical Africa, and the improvement of seed supply systems should accompany sorghum improvement programmes in this region. Demand for sorghum for nontraditional uses is likely to increase. In particular, the use of sorghum as a feed grain, already well established in many industrialized countries, is likely to become more common in developing countries. However, sorghum faces strong competition from maize in the international feed grain market. Similarly, as increased affluence results in increased demand for meat and dairy products, the use of sorghum as a forage crop in intensive production systems in many tropical regions is likely to expand. The use of sorghum as a raw material for industrial processes will also increase. Research should focus on innovations that are likely to reduce the costs of production of sorghum. This should include research to increase yield levels of available cultivars, and to improve agronomic practices. Emphasis should be placed on enhancing resistance to the main biotic and abiotic stresses and on production of cultivars richer in high quality proteins. Sorghum dye may profit from the trend of increasing use of natural colourants in foods and cosmetics. Rising harvesting costs of broomcorn in North America and Europe may offer possibilities for expanding this commodity in Africa. Major references Chantereau et al., 1997; de Vries & Toenniessen, 2001; de Wet, 1978; Doggett, 1988; Murty & Renard, 2001; Rooney & Serna-Saldivar, 2000; Smith & Frederiksen, 2000; Stenhouse & Tippayaruk, 1996; Sten-

173 SPOROBOLUS 175 house et al, 1997; Taylor, Other references Balole, 2001; Bellemare, 1993; Burkill, 1994; Byth (Editor), 1993; Dalziel, 1926; Gao et al., 2005; Harlan & de Wet, 1972; Kouda-Bonafos et al., 1994; Ministry of Agriculture and Rural Development, 2002; National Research Council, 1996; Neuwinger, 2000; Ogwumike, 2002; Pale et al., 1997; Phillips, 1995; Reddy, Ramesh & Reddy, 2004; Rey et al, 1993; Sanders, Ahmed & Nell, 2000; Seshu Reddy, 1991; USDA, 2004; Westphal, Sources of illustration Stenhouse & Tippayaruk, Authors T.V. Balole & G.M. Legwaila Based on PROSEA 10: Cereals. SPOROBOLUS FIMBRIATUS (Trin.) Nees Protologue Fl. Afr. austral, ill.: 156 (1841). Family Poaceae (Gramineae) Chromosome number 2n - 18, 36, 54 Vernacular names Dropseed, perennial dropseed grass, fringed dropseed (En). Origin and geographic distribution Sporobolus fimbriatus is found wild and occasionally cultivated from Sudan and Somalia southwards to South Africa. It has been introduced elsewhere, e.g. into the United States. Uses In southern Africa the grains of Sporobolus fimbriatus are eaten during times of food shortage; they may be ground to prepare a porridge. Sporobolus fimbriatus is a good pasture grass and is browsed by stock, e.g. sheep and cattle. It has been planted for soil stabilization. Properties In South Africa the crude protein content of Sporobolus fimbriatus ranges from 14% in spring to 10% in autumn, and the digestibility from 70% in spring to 63% in autumn. The plant may contain hydrocyanic acid, but poisoning is seldom a problem. Botany Perennial, tufted grass up to 1.7 m tall, with a short rhizome; stem (culm) 2-3 mm in diameter at the base, erect, usually unbranched. Leaves mostly basal, simple; basal leaf sheath papery, glabrous or hairy along the margins, terete to strongly compressed and keeled, persistent; ligule ciliate; leaf blade linear, 10-30(-60) cm x 2-7.5(-14) mm, tapering to a filiform apex, flat, folded or involute, the white midrib prominent above, rough on the surfaces. Inflorescence a panicle cm long, linear to lanceolate, the branches not in whorls, 2-12 cm long, smooth or somewhat rough, with the spikelets on the secondary or short tertiary branchlets. Spikelet mm long, dark green, 1-flowered; lower glume narrowly oblong to lanceolate, mm long, veinless, upper glume narrowly ovate, mm long, 1-veined; lemma narrowly ovate, as long as the spikelet or almost so, 1-veined; palea similar to lemma, but 2-veined; stamens 3, c. 1 mm long; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain), obovoid, c. 0.5 mm long, truncate, tetragonal in section. Sporobolus comprises about 160 species and occurs in the tropics and subtropics, extending into warm temperate regions. It may resemble Eragrostis, which differs in its 2-manyflowered spikelets (1-flowered in Sporobolus) and 3-veined lemma (1-veined in Sporobolus). The species of Sporobolus are often difficult to identify because they intergrade to such an extent that their limits are often not sharply defined. This is also the case for the variable Sporobolus fimbriatus. Sporobolus fimbriatus follows the C4-cycle photosynthetic pathway. Ecology Sporobolus fimbriatus is commonly found up to 2000 m altitude in open woodland and grassland, often in shallow rainwater pans, sometimes on rocky hillsides, also in disturbed or shady locations. Management The grain of Sporobolus fimbriatus is mostly collected from the wild. In experiments in South Africa ungrazed planted pasture of Sporobolus fimbriatus produced 3.3 t dry matter per ha per year, and grazed pasture 2.7 t dry matter per ha per year. Genetic resources and breeding A collection of 47 accessions of Sporobolus fimbriatus (46 from South Africa and 1 from Botswana) is held in the United States (USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington). In Africa germplasm collections are held in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 21 accessions), South Africa (Grassland Research Centre, Department of Agricultural Development, Pretoria, 4 accessions) and Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa, 1 accession). In view of its wide distribution and common occurrence Sporobolus fimbriatus is not threatened by genetic erosion. Prospects The present role of Sporobolus fimbriatus seems limited to being a local source of food during times of shortage and of fodder. It is unlikely to increase in importance in the future. Major references Clayton, Phillips & Renvoize, 1974; Cope, 1995; Cope, 1999; Gibbs Rus-

174 176 CEREALS AND PULSES sell et al., 1990; Phillips, Other references Ben-Shahar, 1991; du Pisani & Knight, 1988; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Klaassen & Craven, 2003; Myre, 1972; Sânchez-Monge y Parellada, 1981; Sharma & Sharma, 1979; van der Westhuizen et al., 2001; van Wyk & Gericke, 2000; Watt & Breyer-Brandwijk, Authors M. Brink SPOROBOLUS PANICOIDES A.Rich. Protologue Tent. fl. abyss. 2: 399 (1850). Family Poaceae (Gramineae) Vernacular names Famine grass (En). Origin and geographic distribution Sporobolus panicoides is found in East and southern Africa from Sudan and Ethiopia southwards to South Africa, and in tropical Arabia. Uses The grains of Sporobolus panicoides are eaten during times of food shortage. Botany Annual, slender grass up to 1 m tall; stem (culm) erect, solitary or tufted. Leaves simple; leaf sheath papery, glabrous, but hairy near the margins, slightly compressed; blade linear, 5-30 cm x 2-6 mm, attenuate at apex, flat or involute, pale green, glabrous or sparsely hairy above. Inflorescence a narrowly ellipsoid panicle 4-22 cm long, the branches in a succession of whorls, with 1-4 spikelets per branch. Spikelet mm long, pallid with purple tinge above, 1-flowered; lower glume1 1.5 mm long, rarely minute, narrowly ovate to lanceolate, obtuse to acute at apex, veinless, glabrous, upper glume as long as the spikelet, elliptical-oblong to ovate, acute at apex, 1- veined, glabrous; lemma a little shorter than spikelet, elliptical-ovate, 1-veined; palea 2- veined; stamens 3, mm long; ovary superior, with 2 plumose stigmas. Fruit a caryopsis (grain), 1-2 mm in diameter, oblong-globose, bright brown or orange. Sporobolus comprises about 160 species and occurs in the tropics and subtropics, extending into warm temperate regions. It resembles Eragrostis, which differs in its 2-manyflowered spikelets (1-flowered in Sporobolus) and 3-veined lemma (1-veined in Sporobolus). The species of Sporobolus are often difficult to identify because they intergrade to such an extent that their limits are often not sharply defined. However, Sporobolus panicoides is easily recognized by its comparatively large, brightly coloured grain, the sparsity of spikelets on the panicle branches and the partially or complete sterile lowermost panicle branch whorl. Ecology Sporobolus panicoides is locally common in sunny or lightly shaded locations, up to 2100 m altitude, in woodland on sandy soils, in granite sandveld and on rocky hillsides, often at roadsides or in other disturbed localities. Management The grains of Sporobolus panicoides are only collected from the wild. Genetic resources and breeding One accession of Sporobolus panicoides is kept at the National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu. Sporobolus panicoides is not threatened by genetic erosion as it is widespread and locally common. Prospects The present role of Sporobolus panicoides is very limited, being a local source of food during times of shortage. It is not probable that it will become more important in the future. Major references Clayton, Phillips & Renvoize, 1974; Cope, 1995; Cope, 1999; Gibbs Russell et al., 1990; Phillips, Other references Fröman & Persson, 1974; IPGRI, undated; Klaassen & Craven, 2003; Mackie, 1976; Shava & Mapaura, Authors M. Brink TRITICUM AESTIVUM L. Protologue Sp. pi. 1: 85 (1753). Family Poaceae (Gramineae) Chromosome number 2re = 42 Synonyms Triticum vulgare Vill. (1787). Vernacular names Bread wheat, common wheat, wheat (En). Blé tendre, blé, froment (Fr). Trigo mole, trigo (Po). Ngano (Sw). Origin and geographic distribution Bread wheat arose in the corridor extending from Armenia in Transcaucasia to the south-west coastal areas of the Caspian Sea in Iran. Hybridization of a wild Aegilops species (Aegilops tauschii Coss., with the D-genome) with emmer, an old type of cultivated wheat belonging to Triticum turgidum L., gave rise to the hexaploid wheats, but it is unknown whether bread wheat or spelt wheat (Triticum spelta L.) appeared first. The earliest archaeological finds of spelt wheat are from the southern Caspian area and are dated at around 5000 BC. Finds of bread wheat are difficult to distinguish from durum wheat (Triticum turgidum), but one thinks that those found in the

175 TRITICUM 177 Triticum aestivum -planted Caucasus, on the anatolian plateau (Turkey), in Central Europe and in Central Asia from the fifth millennium onwards belong to bread wheat. The D-genome in fact conferred to bread wheat and spelt wheat the adaptation to cold winters and humid summers, allowing them to conquer temperate Eurasia, whereas the Mediterranean remained the area of emmer and durum wheat. By the third millennium BC, bread wheat had reached China. In 1529, the Spanish took it to the New World. Bread wheat was introduced into tropical Africa by Arab traders, missionaries and colonial settlers. It is not known exactly when it reached Ethiopia. It was brought from northern Africa to West Africa, where it was already known around 1000 AD. In the early 20 th century it was introduced into Kenya and eastern DR Congo. Bread wheat today is grown in almost all parts of the world. In tropical Africa, it is mainly produced in Nigeria, Sudan, Ethiopia, Kenya, Tanzania, Zambia and Zimbabwe. Uses Bread wheat flour is made into numerous products including bread (leavened or flat; baked, steamed or deep fried), pastries, crackers, biscuits, pretzels, noodles, farina, breakfast foods, baby foods and food thickeners. It is also used as a brewing ingredient in certain beverages (white beer). Leavened breads are the most popular use of wheat in almost all parts of the world. Increased bread consumption is often linked to increasing urbanization and higher per capita income. Bread wheat utilization has also been adapted to local cuisine. In Ethiopia, for instance, the flour is used to prepare 'injera' (pancake-like unleavened bread), porridge and soup. The grain is eaten as a snack and during social gatherings as 'nitro' (boiled whole grain often mixed with pulses), 'kollo' (roasted grain) and 'dabo-kollo' (ground and seasoned dough, shaped and deep fried). Industrial uses of wheat products centre on the production of glues, alcohol, oil and gluten. By-products of flour milling, particularly the bran, are used almost entirely to feed livestock, poultry or prawns. Wheat germ (from wheat embryos) is sold as a human food supplement. Straw is fed to ruminants or used for bedding material, thatching, wickerwork, newsprint, cardboard, packing material, fuel and as substrate for mushroom production. In many dry parts of the world it is chopped and mixed with clay to produce building material. Production and international trade According to FAO estimates, the average world production of wheat grain (bread wheat and durum wheat together) in amounted to 576 million t/year from 209 million ha. Worldwide, bread wheat constitutes more than 90% of the area under the cultivated wheats. The main wheat producing countries are China (96.8 million t/year from 25.2 million ha), India (71.0 million t/year from 26.4 million ha), the United States (56.9 million t/year from 20.6 million ha), the Russian Federation (39.4 million t/year from 21.7 million ha) and France (35.1 million t/year from 5.0 million ha). Wheat production in tropical Africa in was 2.5 million t/year from 1.6 million ha, the main producing countries being Ethiopia (1.4 million t/year from 1.1 million ha), Kenya (272,000 t/year from 137,000 ha), Sudan (254,000 t/year from 124,000 ha), Zimbabwe (237,000 t/year from 43,000 ha), Zambia (87,000 t/year from 13,000 ha), Tanzania (82,000 t/year from 60,000 ha) and Nigeria (75,000 t/year from 53,000 ha). In Ethiopia close to 50% of the wheat production consists of bread wheat, the other 50%of durum wheat. From to the world production of wheat increased from 248 to 576 million t/year, whereas the harvested area remained stable at around 210 million ha. In the same period the wheat production in tropical Africa increased from 960,000 to 2.5 million t/year, and the harvested area from 1.2 to 1.6 million ha. Average world export of wheat amounted to 115 million t/year in , the main exporters being the United States (26.7 million t/year), Canada (16.5 million t/year), Australia (15.9 million t/year), France (15.9 million t/year) and Argentina (10.0 million t/year).

176 178 CEREALS AND PULSES Main importers are Italy, Brazil, Japan and Iran, each importing more than 5 million t/year. All countries in tropical Africa are net importers. The main importer in tropical Africa is Nigeria (1.9 million t/year in ), followed by Ethiopia (770,000 t/year), Sudan (710,000 t/year) and Kenya (570,000 t/year). The share of food aid in wheat imports is as high as 80%for some countries. Properties The composition of wheat grain is 7-8% coat material, 90% endosperm and 2-3% embryo. The embryo mainly comprises oil and protein, and little starch. The endosperm is starchy, and is surrounded by the aleurone layer which is rich in proteins. When a wheat grain is milled, the outer layers and embryo are separated from the endosperm. The pulverized endosperm becomes wheat flour, while the other parts form the bran. The endosperm varies both in hardness and vitreousness: hard bread wheat grain high in gluten protein tends to be vitreous and low-protein soft wheat grain tends to be opaque. Hard bread wheat grain is best suited for bread making while the soft wheat grain is best for cookies, cakes and pastries. Flour colour varies from white to slightly yellow. Bread wheat grain (hard red spring type) contains per 100 g edible portion: water 12.8 g, energy 1377 kj (329 kcal), protein 15.4 g, fat 1.9 g, carbohydrate 68.0 g, dietary fibre 12.2 g, Ca 25 mg, Mg 124 mg, P 332 mg, Fe 3.6 mg, Zn 2.8 mg, vitamin A 9 IU, thiamin 0.50 mg, riboflavin 0.11 mg, niacin 5.7 mg, vitamin BÖ 0.34 mg, folate 43 ug and ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 195 mg, lysine 404 mg, methionine 230 mg, phenylalanine 724 mg, threonine 433 mg, valine 679 mg, leucine 1038 mg and isoleucine 541 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 727 mg, palmitic acid 283 mg and oleic acid 236 mg. Soft, white bread wheat grain contains per 100 g edible portion: water 10.4 g, energy 1423 kj (340 kcal), protein 10.7 g, fat 2.0 g, carbohydrate 75.4 g, dietary fibre 12.7 g, Ca 34 mg, Mg 90 mg, P 402 mg, Fe 5.4 mg, Zn 3.5 mg, vitamin A 9 IU, thiamin 0.41 mg, riboflavin 0.11 mg, niacin 4.8 mg, vitamin B mg, folate 41 ig and ascorbic acid 0 mg (USDA, 2005). Bread wheat grain is deficient in the amino acids lysine and threonine, and somewhat in isoleucine and valine. It is a good source of B-group vitamins and minerals. Wheat grain possesses a unique viscoelastic and insoluble storage protein complex known as gluten, comprising 78-85% of the total wheat endosperm protein. Gluten is composed mainly of glutenin (polymeric) and gliadin (monomeric ) proteins. Glutenins confer elasticity and dough strength, while gliadins confer mainly viscous flow and extensibility to the gluten complex. Wheat flour contains roughly equal amounts of glutenins and gliadins, and their imbalance may influence its visco-elastic properties. Description Annual, tufted grass up to 150 cm tall, with 2-5(-40) tillers; stem (culm) cylindrical, smooth, hollow except at nodes. Leaves distichously alternate, simple and entire; leaf sheath rounded, auricled; ligule membranous; blade linear, cm x 1 2 cm, parallel-veined, flat, glabrous or pubescent. Inflorescence a terminal, distichous spike 4 18 cm long, with sessile spikelets borne solitary on zigzag rachis. Spikelet mm long, laterally compressed, 3-9-flowered, with bisexual florets, but 1-2 uppermost ones usually rudimentary, sometimes only 1 of the florets bisexual; glumes almost equal, oblong, shorter than spikelet, thinly leathery, keeled towards the tip, apiculate to awned; lemma rounded on back but keeled towards the tip, leathery, Triticum aestivum - 1, lower part of plant; 2, ligule and auricles; 3, inflorescence; 4, spikelet; 5, floret (lemma andpalea removed); 6, grains. Source: PROSEA

177 TRITICUM 179 awned or blunt; palea 2-keeled, hairy on the keels; lodicules 2, ciliate; stamens 3; ovary superior, tipped by a small fleshy hairy appendage and with 2 plumose stigmas. Fruit an ellipsoid caryopsis (grain), at one side with a central groove, reddish brown to yellow or white. Other botanical information Triticum is a classic example of allopolyploidy consisting of diploid (2/i - 14), tetraploid (2n = 28) and hexaploid (2re = 42) species. Selection at the diploid and tetraploid levels has proceeded from wild species with hulled grain and brittle rachis to the free-threshing species with tough rachis; hexaploid wheats are not known in the wild, they appeared in cultivation. The classification of the genus Triticum and other related genera within the tribe Triticeae was strongly debated. Polyploidy and biphyletic genome differentiation (B vs. G genome) are isolating mechanisms offering adequate species borders. In this approach, Triticum comprises only 5-6 species, including the diploid Triticum monococcum L. (einkorn, grown sporadically in southern Europe and western Asia), the tetraploid Triticum turgidum L. and the hexaploid Triticum aestivum L. (comprising all cultivated hexaploids). Spelt wheat (Triticum spelta L.) is sometimes separated from Triticum aestivum. It is a hexaploid, not freethreshing wheat, with only 2 3 florets per spikelet, cultivated in small quantities in Europe, Africa and on the plateau of western Iran. It can be cultivated under extreme circumstances, not demanding fertile soils, being relatively disease resistant, and having good taste, food and baking qualities. Before 1850 it was a very important wheat in Europe, declining afterwards, especially because it has to be hulled before milling, but is now gaining in popularity in organic wheat cultivation. Commercially, wheat is classified into distinct categories of grain hardness (soft, mediumhard, and hard) and colour (red, white and amber). Based on growing habit, bread wheat is divided into two subclasses, spring or winter, but facultative types exist. These subclasses in turn may also be divided into grades, which are generally used to adjust prices, based mainly on grain soundness (effects of rain, heat, frost, insect and mould damage), cleanliness, grain protein content and cc-amylase activity. In tropical Africa mostly spring wheats are grown. Hybrids of wheats (tetraploid or hexaploid) and rye called triticale (xtriticosecale) have been developed and these show a mix of characteristics from the parents, combining the hardiness of rye with the high yield and quality of wheat. Triticale is presently grown only locally in tropical Africa, e.g. in Ethiopia, Kenya, Tanzania and Madagascar, and also in northern Africa and South Africa. As a new food crop, it fell short of expectations, but it is becoming increasingly popular as a forage crop. Growth and development Germination of wheat occurs at temperatures of 4-37 C, the optimum being C. The radicle emerges first and the coleoptile emerges 4-6 days after germination. The primary roots may remain functional for life unless destroyed by disease or mechanical injury, but they constitute only a small portion of the total root system. The first true leaf of the seedling emerges from the coleoptile. Secondary roots start to develop about two weeks after seedling emergence. They arise from the basal nodes and form the permanent root system, which spreads out and may penetrate as deep as 2 m, but normally no more than 1 m. Leaf and tiller production increase rapidly soon after crop emergence. The duration of the vegetative stage may vary from days depending on temperature and the cultivar's vernalization and daylength response. For floral induction, spring types usually require temperatures between 7 C and 18 C for 5-15 days, while winter types require temperatures between 0 C and 7 C for days. Flowering begins at the middle third of the spike and continues towards the basal and apical parts in 3-5 days. All spike-bearing tillers eventually flower almost simultaneously. Wheat is normally self-pollinated; crosspollination is 1-4%. Pollen is largely shed within the floret. Stigmas remain receptive for 4-13 days. Pollen is viable for up to 30 minutes only. Grains in the centre of the spike and in the proximal florets tend to be larger than the other ones. Physiological maturity is reached when the flag leaf (uppermost leaf) and spikes turn yellow and the moisture content of the fully formed grain has dropped to 25 35%. The complete crop cycle of bread wheat varies from days in tropical Africa. Ecology Bread wheat can be grown from within the Arctic Circle to near the equator, but it is most successful between N and S. Optimum temperatures for development are C, with minima of 3-4 C and maxima of C. An average temperature of about 18 C is optimal for yield. Temperatures above 35 C stop photosynthesis and growth, and at 40 C the heat kills the crop.

178 180 CEREALS AND PULSES Wheat does not grow well under very warm conditions with high relative humidity, and in the tropics it is best grown at higher elevations ( m) or in the cooler months of the year. Bread wheat requires at least 250 mm water during the growing season for a good crop; it can be grown in areas that receive mm rain annually. The sensitivity to daylength differs among genotypes, but most are quantitative long-day plants; they flower earlier at long daylengths, but they do not require a particular daylength to induce flowering. Soils best suited for bread wheat production are well aerated, well drained, and deep, with 0.5% or more organic matter. Optimum soil ph ranges between 5.5 and 7.5. Wheat is sensitive to soil salinity. Propagation and planting Bread wheat is propagated by seed. The 1000-seed weight is g. It is advisable to use certified seed that has been treated with fungicides against soil- and seed-borne diseases, but this is rarely practised in tropical Africa. Wheat is sown by hand or machine. When broadcast, the seed is incorporated in the soil using an animal-drawn plough or machine-drawn disc. The seed may also be dibbled directly into a furrow behind a plough and covered, or machine-planted in rows. Common seed rates are kg/ha for broadcasting and kg/ha for rowplanting. The optimum spacing is cm between rows, but it may extend up to 35 cm. The sowing depth is 2-5(-12) cm, with deeper planting required in dry conditions. At a sowing depth beyond cm seedling emergence is poor. When using a no-till planting machine, sowing can be done straight into the stubble of the previous crop. For rainfed wheat, the seed can be dry-sown, before the start of the rainy season, or when the soil is moist. Bread wheat is usually grown in sole cropping. Management Uniform crop stand and early vigour discourage weed growth in bread wheat. In this respect tillering allows the crop to compensate for poor stands and variable weather conditions. Yield losses due to weeds are caused by early competition in the first 4-5 weeks. Hand weeding, tillage practices, stubble management, pre-sowing irrigation, proper crop rotation and herbicides may control weeds. Herbicide use in tropical Africa ranges from little to none in many countries (e.g. Sudan, Rwanda, Burundi, Madagascar) to almost complete coverage in Kenya, Tanzania, Zambia and Zimbabwe. In tropical Africa bread wheat is produced mainly under rainfed conditions, except in Malawi, Zambia and Zimbabwe where it is grown as an irrigated (flood and sprinkler) 'winter' season crop. In Nigeria wheat production is restricted to the river basin irrigation schemes of its northern states. Irrigation has great potential to increase wheat production in Sudan and Somalia. Care must be taken not to over-irrigate since wheat is sensitive to early waterlogging. Irrigation timing is based either on pre-defined crop stages or on estimates of soil moisture depletion. The mean nutrient removal per 1 t/ha of grain is kg N, 5-8 kg P, kg K, 2-4 kg S, 3-4 kg Ca, kg Mg, and smaller amounts of micronutrients. The exact values depend on the available nutrients and water in the soil, the temperature, and the cultivar. Average fertilizer rates in tropical Africa range from 9 kg N and 10 kg P on rainfed wheat in Ethiopia to 180 kg N, 84 kg P and 50 kg K on irrigated wheat in Zimbabwe. Commercial fertilizer application ranges from less than 1%of the wheat area in Burundi to 100% in Kenya and Zimbabwe. Organic manure and compost are not commonly used on wheat, except in Rwanda. Boron deficiency, resulting in grain set failure, can be observed on certain soils; boron is applied to irrigated wheat in Zambia, Zimbabwe and Madagascar. Copper is applied to most rainfed wheat in Kenya, and manganese is needed in certain areas of Tanzania. Soil acidity can be a constraint, e.g. in wheat production areas at lower elevations in Zambia. Liming might raise the ph, but its economic returns are poor for rainfed wheat. Wheat is best rotated with non-grass crops, particularly with pulses. In the highland areas of East Africa wheat is grown continuously or in rotation with other cereals, pulses or rapeseed (Brassica oilseed crops). In other regions double cropping systems are common, with irrigated wheat grown in the cool dry season and crops such as cotton, sorghum, maize, soya bean and groundnut in the hot rainy season. In Zimbabwe, for instance, double cropping of irrigated wheat and rainfed soya bean is widely adopted, with the same machinery for sowing and harvesting used for both crops. In tropical Africa wheat is produced in farming systems ranging from small scale, labourintensive, rainfed systems, e.g. in Kenya and southern Tanzania, to highly mechanized schemes and farms, e.g. in Nigeria, Sudan, northern and central Tanzania and Zimbabwe.

179 TEITICUM 181 Diseases and pests Bread wheat is affected by several diseases and pests. In tropical Africa stripe rust or yellow rust (Puccinia striiformis), spread by air-borne uredospores, and Septoria blotches, particularly Septoria leaf blotch (Septoria tritici, synonym: Mycosphaerella graminicola), are the major diseases in the highlands. Stem rust or black rust (Puccinia graminis) can be very damaging in Ethiopia, Kenya and some parts of Sudan; like stripe rust it is spread by air-borne uredospores. Other diseases important in some years are common bunt (Tilletia spp.), loose smut (Ustilago tritici, synonym: Ustilago nuda f.sp. tritici), barley yellow dwarf virus (BYDV) and bacterial leaf streak or black chaff (Xanthomonas translucens). The use of resistant cultivars is the most effective control measure against these diseases. However, resistance breakdown is very frequent for stripe rust. Fungicide application to control stripe rust occurs in Kenya, Uganda and Tanzania. The most important insect pests in tropical Africa are aphids, which may also transmit viruses. The African migratory locust (Locusta migratoria) is a periodic pest that causes crop damage in northern and eastern Ethiopia. The Hessian fly (Mayetiola destructor) has long been an important pest in regions adjacent to the Mediterranean Sea in northern Africa, southern Europe and western Asia. Pest control with commercial insecticides in tropical Africa is rare, except in Sudan, Zambia and Zimbabwe for aphids. Birds (especially Quelea quelea) are especially important in irrigated wheat. Important storage insects, e.g. in Ethiopia, include Sitophilus spp. on whole grains, and Tribolium spp. and Ephestia cautella (synonym: Cadra cautella, flower moth) on wheat flour. Clean storage conditions and maintaining grain moisture and temperature at sufficiently low levels inhibit insect activity and development. Rodents, mainly the black rat (Rattus rattus), also damage stored seeds. Harvesting In tropical Africa bread wheat is usually harvested with sickles or knives, and on large-scale farms with combines. A crop harvested at physiological maturity (grain moisture content 25-35%) must be dried thoroughly before threshing. Wet weather at harvest time can cause serious losses in grain quality because the grain sprouts readily. Sickle-harvested wheat plants are stacked or spread out to dry in the sun. Threshing is done by trampling animals, by beating bagged spikes, or during combine harvesting. In most parts of tropical Africa wheat stubble is grazed by livestock. Yield Yields of bread wheat in tropical Africa vary from 400 kg/ha in Somalia and 700 kg/ha in Angola to 5 t/ha in Zambia and 6.3 t/ha in Zimbabwe. The mean yield of wheat in tropical Africa is estimated at about 1.5 t/ha. Lower yields are due to high temperature, high humidity, disease pressure and the low levels of fertilizer applied. Maximum recorded grain yields of irrigated winter and spring wheats are 14 and 9.5 t/ha, respectively; the absolute maximum yield, based on genetic potential, is estimated at 20 t/ha. Handling after harvest Threshed grain of bread wheat is winnowed, cleaned and prepared for store or market. Seeds should be dried to a moisture content of 13 14% for safe storage. High temperatures and moist conditions may result in spoilage. Regular re-drying may be necessary to maintain seed viability, if the seed is not stored in an airtight container. Genetic resources The International Maize and Wheat Improvement Center (CIMMYT), Mexico City, Mexico (60,400 accessions) and the International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria (9700 accessions) maintain extensive germplasm collections of Triticum aestivum. Large germplasm collections are also held in the United States (USDA-ARS National Small Grains Germplasm Research Facility, Aberdeen, Idaho, 42,000 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, 35,900 accessions), and the Russian Federation (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 25,900 accessions). In tropical Africa the Institute of Biodiversity Conservation (Addis Ababa, Ethiopia) has the largest collection of bread wheat (3400 accessions). Wheat is a priority crop for collection and conservation. More collection needs to be done of its wild and weedy relatives in regions where they are native, of landraces in areas where they have not been collected before, and of new or obsolete improved cultivars with specific traits from breeding programmes around the world for future improvement work. Breeding CIMMYT and ICARDA have large breeding programmes and, upon request, have the international mandate to disseminate bread wheat germplasm to national programmes. In tropical Africa, Ethiopia and Kenya have strong public sector breeding pro-

180 182 CEREALS AND PULSES grammes. In Zimbabwe, there is private sector wheat research, and to some extent in Kenya and Zambia too. High grain yield and disease resistance, mainly to stripe rust and Septoria, are the major objectives. Major breeding methods used in tropical Africa are conventional. A number of high-yielding cultivars, mostly spring types derived from CIMMYT germplasm, have been released in tropical African countries. In 1995 their estimated usage ranged from 5% in Malawi to 100% in Zambia and Zimbabwe. Bread wheat is one of the crops that benefited most from transfer of genes from other species, such as Aegilops, Hordeum and Secale spp., by artificial hybridization, mainly to increase resistance to diseases, especially rusts. Developments in molecular genetics and genetic engineering of wheat have been slower than in cereals such as rice and maize, due to its ploidy level, size and complexity of its genome, the low level of polymorphism and relatively inefficient transformation systems. Consequently, far fewer maps exist in wheat and few QTL (quantitative trait loci) studies have been reported. On the other hand, the hexaploid nature of bread wheat and its amenity to cytogenetic manipulation have offered unique tools for molecular genetic studies. These include the uses of aneuploid stocks to assign molecular markers to specific chromosome arms, of chromosomal deletion stocks for physical mapping and of chromosome substitution lines to map genes of known chromosomal location. The development of improved chemical hybridizing agents, which allows breeders to surmount the problems associated with cytoplasmic male sterile systems, has considerably increased the progress towards the development of economically acceptable hybrid wheat cultivars. Recently, an efficient Agrobacteriummediated transformation system has been developed for the large-scale production of transgenic wheat plants. Private companies have developed transgenic herbicide-resistant bread wheat cultivars, but these have not yet been produced commercially. Prospects Since bread wheat is the most important food grain source for humans, the need to continuously increase its production cannot be overemphasized. Bread consumption from wheat in tropical Africa is low and varies from country to country; wheat consumption ranges from 2.5 kg/person/year in Uganda to 43.3 kg/person/year in Sudan. However, with the increasing trends of urbanization and income, there is likely to be a concomitant demand for traditional and new convenient, processed wheat-based products. No tropical African countries are 100% self-sufficient for wheat and the region is confronted by rapidly increasing wheat imports. In many of these countries wheat production is constrained by limited usage of high-yielding cultivars, fertilizer, other inputs and irrigation. Increases in wheat production may come from area expansion to non-traditional areas, coupled with social and economic incentives, and further increases in yield by agronomic research and breeding. Since the 1990s, area expansion of bread wheat has been observed in Sudan, Ethiopia, Kenya, Tanzania and Zambia. Research to improve wheat yields at a global scale includes further mixing of germplasm through wide hybridization and synthetic hexaploids, biotechnology tools, hybrid wheat, and basic studies on wheat physiology and host-plant relationships of various diseases and pests. Tolerances to drought, heat, aluminium soil acidity and waterlogging are some of the abiotic factors that require continued research attention. Major references CIMMYT, 1985; Curtis, Rajaram & Gomez Macpherson (Editors), 2002; Heisey & Lantican, 1999; Heyene (Editor), 2002; Klatt (Editor), 1988; Payne, Tanner & Abdalla, 1996; Saunders & Hettel (Editors), 1994; Tanner & Raemaekers, 2001; van Ginkel & Villareal, 1996; Wiese, Other references Ageeb et al. (Editors), 1996; Bowden, 1959; Braun et al. (Editors), 1997; Byerlee & Moya, 1993; Dvorak et al., 1998; Edwards, 1997; Feldman, Lupton & Miller, 1995; Gebre-Mariam, Tanner & Hulluka (Editors), 1991; Hanson, Borlaug & Anderson, 1982; Hu et al., 2003; Jordaan, 1999; Khairallah et al, 2001; Phillips, 1995; Pickett, 1993; Quisenberry & Reitz (Editors), 1967; Roelfs, Singh & Saari, 1992; Simmonds & Rajaram (Editors), 1988; USDA, 2005; Walker & Boxall, 1974; Zhou et al., Sources of illustration van Ginkel & Villareal, Authors G. Belay Based on PROSEA 10: Cereals.

181 TRITICUM 183 TRITICUM TURGIDUM L. Protologue Sp. pi. 1: 86 (1753). Family Poaceae (Gramineae) Chromosome number 2n 28 Synonyms Triticum dicoccon Schrank (1789), Triticum durum Desf. (1798). Vernacular names Durum wheat, macaroni wheat (En). Blé dur (Fr). Trigo duro, trigo rijo (Po). Origin and geographic distribution Hybridization between the diploids Triticum urartu Tumanian ex Gandylian (A-genome) and the yet unconfirmed B-genome donor (possibly a species of Aegilops section Sitopsis), followed by chromosome doubling gave rise to the first wild tetraploid wheat. Remains of primitive types of cultivated Triticum turgidum (emmer wheat, which has hulled grain) were discovered at several archaeological sites in Syria and dated at around 8000 BC. Emmer wheat became the predominant cultivated wheat in the Fertile Crescent (southern Turkey, northern Iraq and adjacent regions of Iran and Syria, as well the Joran valley) and spread into much of Asia, northern Africa and Europe. It remained the main wheat for several thousands of years. Free-threshing types, such as durum wheat, arose by accumulation of mutations and subsequent selection from the primitive emmer wheat. Around the beginning of the Christian era durum wheat had replaced emmer in most of the wheat growing areas of the Old World. Durum wheat is now commercially the most important type of Triticum turgidum. It is not certain when and how durum wheat reached tropical Africa, but it might have reached the northern highlands of Ethiopia around 3000 Triticum turgidum -planted BC. In tropical Africa durum wheat is predominantly grown in Ethiopia and to some extent in Eritrea and Angola. In other countries, e.g. Sudan and Tanzania, it has been grown experimentally. Durum wheat is also widely grown in northern Africa (from Morocco to Egypt), Mediterranean Europe (Italy, southern France), Turkey, the Middle East (Syria, Jordan, Iraq), Russia, Asia (Iran, Afghanistan, India, China), North America (Canada and the United States) and Argentina. Uses Throughout the world durum wheat is mainly ground to semolina (coarse flour) that is made into various pasta products (macaroni, spaghetti, noodles) and traditional flat bread (little leavened). In tropical Africa durum wheat utilization has been adapted to the local cuisine. In Ethiopia it is used mainly to make 'kitta' (unleavened bread), 'injera' (flat pancake-like unleavened bread), and homemade alcoholic and non-alcoholic drinks. Durum wheat is also preferred for preparation of 'kinchie' (crushed kernels, cooked with milk or water and mixed with spiced butter), which is often served for breakfast. The grain is eaten as a snack and during social gatherings as 'nifro' (boiled whole grain often mixed with pulses), 'kollo' (roasted grain), and 'dabo-kollo' (ground and seasoned dough, shaped and deep fried). In northern Africa and the Middle East durum wheat is preferred for making couscous; its granules result from the agglomeration of semolina particles. In the Middle East it is also durum wheat which is used for making 'bulghur', i.e. a wheat which is parboiled, dried and then crushed. The straw of durum wheat is fed to animals and used as bedding material for animals and for thatching. Production and international trade Durum wheat and bread wheat statistics are usually combined and therefore individual and reliable statistics on durum wheat are difficult to obtain. According to FAO estimates, the average world production of wheat grain (durum wheat and bread wheat together) in amounted to 576 million t/year from 209 million ha. Worldwide, durum wheat constitutes less than 10% of the area under the cultivated wheats. Major durum wheat producers are northern Africa, where it covers nearly 50% of the total wheat area, the United States, Canada and the Russian Federation. The main durum wheat-producing country in tropical Africa is Ethiopia. Close to 50% of its total wheat production (1.4 million t/year in 1999

182 184 CEREALS AND PULSES 2003) is durum wheat. In Ethiopia durum wheat production is mainly for subsistence. Ethiopia also produced emmer wheat, but this crop is disappearing. Properties Durum wheat grain contains per 100 g edible portion: water 10.9 g, energy 1418 kj (339 kcal), protein 13.7 g, fat 2.5 g, carbohydrate 71.1 g, Ca 34 mg, Mg 144 mg, P 508 mg, Fe 3.5 mg, Zn 4.2 mg, vitamin A 0 IU, thiamin 0.42 mg, riboflavin 0.12 mg, niacin 6.7 mg, vitamin Ek 0.42 mg, folate 43 ug and ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 176 mg, lysine 303 mg, methionine 221 mg, phenylalanine 681 mg, threonine 366 mg, valine 594 mg, leucine 934 mg and isoleucine 533 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 930 mg, palmitic acid 422 mg and oleic acid 335 mg (USDA, 2005). Durum wheat grain is deficient in the amino acids lysine and threonine, and somewhat in isoleucine and valine. It is a good source of B-group vitamins and minerals. Durum wheat grain is vitreous, amber in colour, and is the hardest of all wheats. The physical and chemical characteristics of durum wheat gluten provide greater stability of the dough and make it specially suited for pasta products. For preparation of pasta, the grain is milled only as far as the semolina stage; a finely ground flour is not required. In the process of cooking, pasta products of good quality do not disintegrate or become soft, mushy, starchy or sticky. Protein should have a minimum level of 12%. Durum wheat is not suitable for making cakes and leavened bread because of its high gluten content and dough strength. Description Annual, often strongly tufted grass up to 170 cm tall; stem (culm) cylindrical, smooth, hollow except at nodes. Leaves distichously alternate, simple and entire; leaf sheath rounded, auricled; ligule membranous; blade linear, cm x 1-2 cm, parallel-veined, flat, slightly hairy. Inflorescence a terminal, dense, distichous spike 4-12 cm long, with sessile spikelets borne solitary on zigzag, hairy, tough rachis. Spikelet mm long, laterally compressed, 4-7-flowered, with bisexual florets, but the 1 3 uppermost ones usually rudimentary; glumes almost equal, oblong, shorter than to almost as long as spikelet, thinly leathery, 5 11-veined, strongly keeled throughout, apiculate to awned; lemma rounded on back but keeled towards the tip, leathery, with an awn 8-20 cm long; palea 2-keeled, hairy on the keels; lodicules 2, ciliate; stamens 3; ovary superior, tipped by a small fleshy hairy appendage and with 2 plumose stigmas. Fruit an ellipsoid caryopsis (grain), at one side with a central groove. Other botanical information Triticum is a classic example of allopolyploidy consisting of diploid (2/i = 14), tetraploid (2re = 28) and hexaploid (2n = 42) species. Selection at the diploid and tetraploid levels has proceeded from wild species with hulled grain and brittle rachis to the free-threshing species with tough rachis; hexaploid wheats are not known in the wild, they appeared in cultivation. The classification of the genus Triticum and other related genera within the tribe Triticeae was strongly debated. Polyploidy and biphyletic genome differentiation (B vs. G genome) are isolating mechanisms offering adequate species borders. In this approach, Triticum comprises only 5 6 species, including the diploid Triticum monococcum L. (grown sporadically in southern Europe and western Asia), the tetraploid Triticum turgidum L., and the hexaploid Triticum aestivum L. Some tetraploid cultivated wheats are sometimes specifically distinguished from Triticum turgidum. Triticum aethiopicum Jakubz. is a Triticum turgidum - 1, inflorescences; 2, spikelet; 3, grains. Redrawn and adapted by Achmad Satiri Nurhaman

183 TRITICUM 185 special type of free-threshing wheat, a traditional cereal crop in Ethiopia and the southern part of the Arabian Peninsula. Its spikes are loose to dense, its glumes are usually awned and its grain mostly purple. Triticum dicoccon Schrank (emmer wheat) is the oldest cultivated tetraploid wheat, domesticated in the area of Palestine, south-western Syria and northwestern Jordan. It has disarticulating spikes with 2-grained spikelets and hulled grains, not easy to decorticate. At present it is still cultivated in Ethiopia, Iran, Turkey, Transcaucasia, former Yugoslavia, the Czech Republic, Slovakia and India. Triticum durum Desf. is the free-threshing durum wheat or macaroni wheat, that appeared in the Mediterranean, and is cultivated in regions with a hot dry climate; it has its greatest diversity in Ethiopia. It has slender spikes and comparatively long glumes. Triticum polonicum is the freethreshing Galicia wheat (erroneously named 'Polish wheat' by Linnaeus), occasionally cultivated in the same areas as the true durum wheat. It has much longer glumes (2.5 3 cm). In Ethiopia it is found only in mixture with other wheats. The free-threshing rivet wheat or cone wheat (Triticum turgidum L. sensu stricto) is cultivated in northern Africa, southern and central Europe and Asia. It has stout spikes nearly square in section and comparatively short glumes. It is also grown in Ethiopia, usually in mixtures. Most durum wheat cultivars are spring or semi-winter types. Only a few winter types are known. Growth and development Germination of wheat occurs at temperatures of 4-37 C, the optimum being C. The coleoptile emerges 4-6 days after germination. Flowering begins at the middle third of the spike, then rapidly progressing both upward and downward. Durum wheat is predominantly selfpollinated; in Ethiopia cross-pollination rates up to 4.3% have been recorded. Physiological maturity is reached when the moisture content of the fully formed grain has dropped to 25-35%. The complete crop cycle of durum wheat is days in Ethiopia. Ecology Durum wheat is better suited to regions with a low average annual rainfall than bread wheat, e.g. in the Middle East, northern Africa and parts of Mediterranean Europe. In the tropics durum wheat is best grown at higher elevations or in the cooler months of the year. In Ethiopia durum wheat is mostly produced in the central, northern and north-western highlands at m altitude during the main rainy season ('meher') between August and December. Highly rustresistant cultivars are needed to grow durum wheat below 1900 m in Ethiopia. High temperatures and low humidity improve grain quality, and durum wheat is susceptible to low temperatures and severe frosts. The minimum amount of water required for an acceptable crop is 250 mm. Soils best suited for durum wheat are well aerated, well drained and deep, with 0.5% or more organic matter. Optimum soil ph is Durum wheat is sensitive to soil salinity. In Ethiopia durum wheat is preferentially grown on heavy black clay soils (Vertisols); farmers usually delay planting and use surface drainage systems (furrows) to avoid waterlogging. N and micronutrient deficiencies can be limiting on Vertisols. Durum wheat can also be grown on light soils (Andosols), but here short, stiff and disease resistant cultivars are required. Propagation and planting Durum wheat is propagated by seed. The 1000-seed weight is g. Durum wheat can be sown by hand or machine; in Ethiopia it is usually broadcast. Dormancy can be a problem in introduced cultivars, but not in the local Ethiopian landraces. Seeding rate is commonly (-175) kg/ha, the higher rates being necessary on heavy clay soils where stand establishment is usually poor on flat seedbeds. It is advisable to use certified seed that has been treated with fungicides against soil- and seed-borne diseases, but this is not practised in tropical Africa. In Ethiopia an oxen-drawn implement ('maresha') is used to till the land before sowing, with 2-3 ploughings made before planting. In Ethiopia planting dates vary from mid-july to early September. Management Weed competition during tillering of the durum wheat crop, usually in the first days after sowing, is most detrimental to grain yield. Uniform crop stand and early vigour discourage weed growth. Competition occurring later in the crop cycle can affect grain numbers and grain weight, but usually has smaller effects on grain yield. Weeds can be controlled by hand weeding, proper crop rotation, pre-seeding irrigation, machine cultivation, or application of chemical herbicides. In tropical Africa hand weeding remains the most common means of weed control. Blanket fertilizer recommendation rates for durum wheat in Ethiopia are 41 kg N and 26 kg P per ha; additionally 23 kg/ha N can be

184 186 CEREALS AND PULSES top-dressed under heavy rain conditions at early growth stages. However, farmers in Ethiopia do not usually give priority to durum wheat when applying commercial fertilizer. Diseases and pests The most important diseases of durum wheat in tropical Africa are stem rust (Puccinia graminis) and leaf rust (Puccinia recondita f.sp. tritici, synonym: Puccinia triticina). The use of resistant cultivars is the most effective control measure against these diseases. In cooler regions, stripe rust or yellow rust (Puccinia striiformis) limits durum wheat production, e.g. in the Arsi highlands of Ethiopia. The most important insect pests in tropical Africa include aphids (which may also transmit viruses), and grasshoppers. The African migratory locust (Locusta migratoria) is a periodic pest that causes crop damage in northern and eastern Ethiopia. The Hessian fly (Mayetiola destructor) has long been an important pest in regions adjacent to the Mediterranean Sea in northern Africa, southern Europe and western Asia. Control of insect pests with commercial insecticides in tropical Africa is rare. Important storage insects in Ethiopia include Sitophilus spp. on whole grains, and Tribolium spp. and Ephestia cautella (synonym: Cadra cautella, flower moth) on wheat flour. Rodents, mainly the black rat (Rattus rattus), also damage stored seeds. Harvesting In tropical Africa durum wheat is usually harvested with sickles and rarely by machine. A crop harvested at physiological maturity (grain moisture content 25-35%) must be dried thoroughly before threshing. Wet weather at harvest time can cause serious losses in grain quality because the grain sprouts readily. Plants are stacked or spread out to dry in the sun. Threshing is mostly done by trampling animals. Yield Durum wheat yields on farmers' fields in Ethiopia vary from 800 kg/ha to 2.5 t/ha; mean yield is estimated at less than 1 t/ha. Yields tend to be rather low due to the low application of improved cultivars and optimal production practices, and low levels of fertilizer applied. Yield progress in durum wheat has generally been lower than that in bread wheat. However, durum wheat grain yields of 5-6 t/ha can be obtained with irrigation and the use of improved cultivars and better production practices. Straw yields are equally important in Ethiopia and range from 9-15 t/ha. Handling after harvest In tropical Africa, e.g. in Ethiopia, threshed grains of durum wheat are separated from the residues by winnowing. The clean seeds are stored, sold or processed for home consumption. Harvested durum wheat grain should be dried to moisture content of 13 14% for safe storage. High temperatures and moist conditions may result in spoilage. Regular re-drying may be necessary to maintain seed viability, if the seed is not stored in an airtight container. Genetic resources The International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria (21,010 accessions) and the International Maize and Wheat Improvement Center (CIMMYT), Mexico City, Mexico (7880 accessions) maintain large germplasm collections of Triticum turgidum. Large germplasm collections are also held in the United States (USDA-ARS National Small Grains Germplasm Research Facility, Aberdeen, Idaho, 42,030 accessions), the Russian Federation (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 5580 accessions) and Australia (Australian Winter Cereals Collection, Agricultural Research Centre, Tamworth, New South Wales, 5520 accessions). In tropical Africa the Institute of Biodiversity Conservation (Addis Ababa, Ethiopia) has the largest collection of Triticum turgidum (12,500 accessions). Since Ethiopia is an important centre of diversity of durum wheat, several studies since the 1970s have dealt with the magnitude and structure of Ethiopian durum wheat germplasm using morphological, protein, cytological and molecular markers. While the area of durum wheat has decreased since the 1970s, no drastic changes in the overall diversity are evident. Breeding CIMMYT and ICARDA have the international mandate to disseminate durum wheat germplasm to national programmes. In tropical Africa a strong breeding programme has been underway in Ethiopia since High grain yield and disease resistance, mainly to stem and leaf rusts, have been the major objectives, and recently industrial quality has been included. Genotype x environment interactions in Ethiopia are very high and therefore emphasis has shifted from wide to specific adaptation. Major breeding methods are conventional, and include selection from indigenous landraces and introductions from CIMMYT and ICARDA, and hybridization. Greater success was achieved from the international introductions than from the landrace selections. More than 16 durum wheat cultivars have been officially approved, but their area does

185 TYLOSEMA 187 not exceed 10% of the total durum wheat area. 'Boohai', 'Foka', 'Kilinto' and 'Yerer' are among the most widely sown cultivars. Linkage-maps of durum wheat have been developed and important QTLs (quantitative trait loci) for grain quality traits have been identified. The developments in wheat molecular genetics and genetic engineering have been relatively slow, especially when compared to other cereals such as rice and maize, due to its ploidy level, size and complexity of its genome, the low level of polymorphism and relatively inefficient transformation systems. Breeding of durum wheat is less advanced than of bread wheat; in addition it has benefited less in wide hybridization and alien gene transfers. Durum wheat is an important component species for bread wheat breeding through formation of synthetic hexaploids, and for the production and development of triticale ÇxTriticosecale), the hybrid of wheat and rye. Prospects In tropical Africa, Ethiopia has the greatest potential for durum wheat because of its favourable growing environments in the cool dry highlands and tradition of growing the crop. There is an increasing demand for quality durum wheat grain by the local pasta industries, which is usually met through import. Breeding programmes have developed cultivars that meet the quality demand by the industry, but in the absence of premium price over the higher-yielding bread wheat cultivars, farmers are losing interest in growing durum wheat. The future trends of durum wheat production, as a result of unfavourable market prices, therefore may seem discouraging. On the other hand, large-scale commercial farmers are entering into durum wheat production to supply the industry, some even replacing bread wheat due mainly to price competition from imported flour. Adaptive research is needed to develop durum wheat that reliably produces 2-3 t/ha in farmers' fields. More progress is also required in agronomic research, identification of suitable production areas and in establishing an attractive pricing and marketing structure for farmers. The crucial factor is a stable and long-term commitment from the government, the farmers, the private sector (including seed producers) and national research programmes. With this functional partnership in place, Ethiopia could even export quality durum wheat. Major references Bechere, Kebede & Belay, 2001; Bechere, Tesemma & Mitiku, 1994; Gebre-Mariam, Tanner & Hulluka (Editors), 1991; Morris & Sears, 1967; Scarascia Mugnozza (Editor), 1973; Srivastava, 1984; Tanner & Raemaekers, 2001; Tesemma & Belay, 1991; van Ginkel & Villareal, 1996; Wiese, Other references Alamerew et al., 2004; Belay, 1997; Belay, Tesemma & Mituku, 1993; Belay et al., 1997; Bowden, 1959; Curtis, Rajaram & Gomez Macpherson (Editors), 2002; Elouafi & Nachit, 2004; Eticha et al., 2005; Feldman, Lupton & Miller, 1995; Gashawbeza et al., 2003; Jauhar, 2003; Mac Key, 1966; Mohamed, 1999; Payne, Tanner & Abdalla, 1996; Perrino et al., 1996; Phillips, 1995; Tarekegn, 1994; Tsegaye, 1996; USDA, 2005; Walker & Boxall, Sources of illustration Landwehr, 1976; Vaughan & Geissler, Authors G. Belay TYLOSEMAESCULENTUM (Burch.) A.Schreib. Protologue Mitt. Bot. Staatssamml. München 3: 611 (1960). Family Caesalpiniaceae (Leguminosae - Caesalpinioideae) Synonyms Bauhinia esculenta Burch. (1824). Vernacular names Marama bean, morama bean, gemsbok bean, camel's foot (En). Marama (Fr). Origin and geographic distribution Marama bean is native to the Kalahari desert and neighbouring sandy regions in Angola, Namibia, Botswana and South Africa, but it also occurs in Zambia and Mozambique. Experimental cultivation in Kenya, South Africa, Australia, Israel and the United States (Texas) Tylosema esculentum - wild

186 188 CEREALS AND PULSES has been successful. Uses Marama bean is an important part of the diet of the Khoisan people in the Kalahari, where subsistence agriculture is marginal due to drought and low soil fertility, and it is a delicacy among other peoples in southern Africa. The seeds are eaten boiled or roasted. They may be boiled with maize meal or ground into flour to prepare a porridge or a coffee- or cocoalike drink. Roasted seeds are sometimes sold locally but only on a small scale. Marama beans have a pleasant sweet flavour when boiled or roasted, comparable to roasted cashew nuts or almonds, although bitter types are known. The roasted seeds have sometimes been used by Europeans in southern Africa as a culinary substitute for almonds. Immature seeds and stems may be eaten cooked as a vegetable or in soups. The seed oil is used in Botswana for cooking and for making butter. Young tubers are eaten baked, boiled or roasted, as a vegetable dish. Tubers older than 2 years become fibrous and bitter and are usually not eaten, but they are an important emergency source of water for humans and animals. The pods and tubers are recorded to be eaten by animals, but it is not clear whether the foliage is browsed, as contradictory reports exist. Marama bean may have potential as a ground cover or ornamental. Properties Mature, shelled marama bean seeds contain per 100 g: water 3.9 g, energy 2660 kj (635 kcal), protein 31.8 g, fat 42.2 g and carbohydrate 18.9 g (Bower et al., 1988). The protein content of marama bean is comparable to that of soya bean, and the oil content is twice as high as that of soya bean and comparable to that of groundnut. The essential amino-acid composition per 100 g food is: tryptophan 219 mg, lysine 1119 mg, methionine 257 mg, phenylalanine 874 mg, threonine 822 mg, valine 1149 mg, leucine 1774 mg and isoleucine 1119 mg (FAO, 1970). The seeds have a relatively high trypsin inhibitor activity, which can be remedied by cooking. The seed oil is golden-yellow, with a nutty odour and a pleasant, although slightly bitter flavour, and has been described as similar to almond oil in consistency and taste. Its principal fatty acids are oleic acid (48-49%), linoleic acid (19-26%), palmitic acid (12-14%), stearic acid (7-10%) and arachidic acid (3%). Per 100 g dry weight the defatted seed meal contains: energy 194 kj (46 kcal), protein 55.0 g, available starch 13.0 g and fibre 1.6 g. Per 100 g, the tubers of a 5- month-old plant contain: water 92.1 g, protein 2.1 g, fat 0.1 g and carbohydrate 4.4 g. Young tubers have a sweet and pleasant taste and the texture has been described as similar to that of artichoke. The tubers are reddish when dried. Description Perennial herb or shrub, with tuberous root; stems prostrate and trailing, up to 6 m long, herbaceous or lower parts woody, rusty-hairy, with axillary forked tendrils 1-4 cm long. Leaves alternate, simple; stipules 3-5 mm x 2-3 mm; petiole cm long; blade 2- lobed for more than half its length, glabrous or pubescent beneath; lobes reniform, cm x cm. Inflorescence a lateral raceme up to 16 cm long; peduncle 2-4 cm long. Flowers bisexual, zygomorphic, 5-merous, heterostylous; pedicel cm long; sepals free but upper 2 fused, 8-12 mm x 2-3 mm, rusty-hairy; petals unequal, 4 larger ones cm x l_ 1.5 cm and tapering into a basal claw, the upper one smaller, yellow turning reddish with age; stamens 2, free, with filaments 6-12 mm long, staminodes 8, with filaments 3-6 mm long; ovary superior, 5-6 mm long, 1-celled, style elongate, stigma small. Fruit an ovoid to oblong pod cm x 3-4 cm, flattened, woody, l-2(-6)-seeded, constricted between the seeds. Seeds ovoid to globose, cm x cm, reddish to brownish black. Tylosema esculentum - 1, part of flowering stem; 2, fruit; 3, seed. Redrawn and adapted by Achmad Satiri Nurhaman

187 TYLOSEMA 189 Other botanical information Tylosema comprises 5 species and occurs in southern and eastern Africa. Some taxonomists do not consider Tylosema a separate genus, but include it in Bauhinia. Tylosema fassoglense (Schweinf.) Torre & Hillc, which also has edible seeds and tubers, has longer leaf stalks and more shallowly lobed leaves. Growth and development In field experiments in Kenya marama bean seeds started to germinate 9-10 days after planting. Once germinated the seedlings develop rapidly. Marama bean has been recorded as not flowering until the 3 rd or 4 th year after planting, but in experiments in Texas plants started flowering after 2 years, and fruits and seeds were formed after 3.5 years. In its native area marama bean flowers from October to March. It is predominantly outcrossing and may be self-incompatible; it is pollinated by insects. In cultivation fruit and seed set tend to be low. In southern Africa the stems die back during the dry and cool period (May-August), but the tuber remains viable and produces new stems when the temperature rises. Marama bean does not form root nodules and relies on soil nitrogen. Its drought-adaptive mechanisms include closure of leaves, the maintenance of green-leaf area under drought by early stomatal closure, and the use of moisture reserves in the tuber (which shrinks greatly in dry years). Marama bean plants have long trailing stems that creep along the ground and avoid the effects of the strong destructive windstorms of the Kalahari. Ecology Marama bean occurs naturally in an extreme environment with high temperatures (typical daily maximum of 37 C in the growing season), low rainfall ( mm) and long periods of drought. It is found on sandy and limestone (including dolomite) soils, but not on soils developed over granite or basalt. Marama bean is found in grassland and wooded grassland vegetation. It occurs in localized patches. Propagation and planting Propagation of marama bean is by seed. Germination is sometimes said to be improved by scarification. Soaking will kill the seed and it should not be sown in waterlogged soils. The 1000-seed weight is 2-3 kg. Preliminary results under laboratory conditions show that vegetative propagation using sprouts is possible. Harvesting The seeds of marama bean are collected in its native area from the wild and by hand. The tubers are harvested by handdigging when they weigh about 1 kg. Yield In the Kalahari young tubers of marama bean of 1 year old and about 1 kg in weight are preferred. Tubers may reach 10 kg after a few years and tuber weights of up to 300 kg have been reported; a tuber weighing 277 kg contained water. Information on seed yields of marama bean is not available. Handling after harvest Raw seeds of marama bean store well and remain edible for years. Dry storage is preferable. Oil can be extracted from the seeds by conventional pressing or solvent extraction. To obtain water from the tuber, the skin is scraped away and a hole is made. The flesh in and around the hole is mashed with a wooden stick until the consistency is porridge-like. This porridge is put into a piece of fabric and the water is squeezed out with both hands. The water can also be extracted from the tubers by pounding pieces of it in a container. Genetic resources Marama bean is considered neither rare nor threatened. No substantial germplasm collections are known to exist. The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, the National Genebank, Muguga, Kenya, and the Plant Genetic Resources Unit of the Agricultural Research Council, Pretoria, South Africa, have 1 accession each. Marama bean shows orthodox seed storage behaviour. Breeding Programmes for selection and breeding work of marama bean are recorded to be underway in the United States, Australia and Israel. RAPD analysis of 3 populations from various parts of Botswana has shown that a considerable amount of genetic variation exists within marama bean, most of it within rather than between populations. Sufficient genetic variation for breeding may be found by sampling plants from 1 or 2 populations. Prospects Marama bean is regarded as having considerable potential as a crop for arid and semi-arid regions, and it is being investigated in Australia, Israel and the United States (Texas). It has potential for its roasted seeds and as a source of oil. However, before large-scale cultivation can be promoted, more information is needed on its ecological requirements, adaptability to cultivation and agronomy. Furthermore, genetic improvement and germplasm collection need attention and research should be carried out on the presence of toxic constituents or antinutritional factors in the seeds and tubers. Major references Bower et al., 1988; Da-

188 190 CEREALS AND PULSES kora, Lawlor & Sibuga, 1999; Keegan & van Staden, 1981; Ladizinsky & Smartt, 2000; Monaghan & Halloran, 1996; National Academy of Sciences, 1979; Powell, 1987; Ross, 1977; van Wyk & Gericke, 2000; Wickens, Other references Brummitt & Ross, 1976; Chandel & Singh, 1984; FAO, 1970; Francis & Campbell, 2003; Graham & Vance, 2003; Hao Gang et al, 2003; Hartley, Tshamekeng & Thomas, 2002; Hornetz, 1993; ILDIS, 2002; IPGRI, undated; Keith & Renew, 1975; Ketshajwang, Holmback & Yeboah, 1998; Leger, 1997; Lock, 1989; Mitchell et al., 2003; Schreiber, 1967; USDA, ARS & National Genetic Resources Program, 2001; Victor, undated; Vietmeyer, 1978; Watt & Breyer-Brandwijk, Sources of illustration Powell, Authors L.J.G. van der Maesen TYLOSEMAFASSOGLENSE (Schweinf.) Torre & Hillc. Protologue Bol. Soc. Brot., ser. 2, 29: 38 (1955). Family Caesalpiniaceae (Leguminosae - Caesalpinioideae) Chromosome number In 52 Synonyms Bauhinia fassoglensis Schweinf. (1868), Bauhinia kirkii Oliv. (1871). Vernacular names Sprawling bauhinia, creeping bauhinia (En). Bauhinia rampant (Fr). Origin and geographic distribution Tylosema fassoglense occurs wild from Sudan and Ethiopia southwards to Namibia, Mozambique and South Africa. Uses The seeds of Tylosema fassoglense are frequently eaten, for instance in DR Congo, Ethiopia, Tanzania, Malawi and South Africa. Immature and mature seeds can be eaten raw, but they are usually cooked or roasted. The pods are also eaten raw or cooked. The seeds are a coffee substitute. The leaves and young branches of Tylosema fassoglense are grazed. In Kenya the Masai and Kipsigis people make rope from the stems and plaited items from the young stems or from the fibres. The fibre is also suitable for making cloth. Water is obtained from the tuber in arid regions, and the tuber is sometimes made into porridge. Sap from the shoots can be used as potable water. The roots are used to produce a brown dye. In Ethiopia the seeds, after being hardened over a fire, are strung into necklaces and bracelets. In traditional African medicine root decoctions of Tylosema fassoglense are taken to treat gastrointestinal problems in various countries. They are also used against anaemia, fever and pneumonia, and to heal the uterus after childbirth. The pulverized tuber is taken for the treatment of venereal diseases. The leaf sap is applied to treat inflammations of the middle ear. Infusions of powdered flowers are drunk against jaundice and hypertension. A decoction of the roots and flowers is drunk to treat impotence. Children are encouraged to eat the pods, because these are thought to be good for the stomach. In veterinary medicine root decoctions of Tylosema fassoglense are administered as a galactagogue to cows before calving, and as a drench for a retained placenta. Properties The composition of seeds of Tylosema fassoglense per 100 g edible portion is: water 7.5 g, energy 1888 kj (451 kcal), protein 43.5 g, fat 32.6 g, carbohydrate 14.6 g, fibre 4.2 g, Ca 80 mg, P 200 mg and Fe 40 mg (Malaisse & Parent, 1985). Seeds collected in DR Congo and Burundi yielded g oil per 100 g, with as principal fatty acids linoleic acid (36 43%), oleic acid (33-35%), palmitic acid (12-16%), stearic acid (3-5%), behenic acid (3-5%) and arachidic acid (2-4%). Per 100 g the defatted seedcake meal contains 59 g protein, with a very high level of tyrosine (7-9 g per 100 g dry weight) and relatively high proportions of lysine and proline (3-4 g and 4-5 g per 100 g dry weight, respectively). The seedcake meal contains substantial amounts of trypsin inhibitors (295 TUI/mg) and phytate (3.5 g per 100 g dry weight), but cyanogenic glycosides have not been detected. For human or animal consumption of the seedcake, removal or inactivation of the trypsin inhibitors is recommended. Recently a cyanoglucoside (lithospermoside) has been isolated from the roots. In the rainy season the tuberous root may contain 86% water. Botany Perennial herb or shrub, with tuberous root; stem prostrate and trailing or climbing, up to 6 m long, herbaceous or woody below, young parts rusty-tomentose or rustyhairy, with axillary forked tendrils (2-)3 6.5( 9.5) mm long. Leaves alternate, simple; stipules 2-4 mm x 2 mm, persistent; petiole (2-)3-10(-20) cm long; blade bilobed for up to onethird (sometimes up to half) its length, (5-)7-13(-20) cm x (4-)8-15(-24) cm, base deeply cordate, lobes ovate to obovate, sometimes rounded, subglabrous to densely rusty pubescent beneath. Inflorescence a lateral raceme 5-

189 UROCHLOA cm long; peduncle (2-)4-12(-18) cm long. Flowers bisexual, zygomorphic, 5-merous, heterostylous; pedicel (1.5 )2-4.5(-6) cm long; sepals l-1.5(-2.5) cm x 3 4 mm, with upper 2 completely united and the other 3 free; petals unequal, 4 (larger ones) obovate-circular, (1.5 ) 2-4(-4.5) cm x 1-3 cm and tapering into a basal claw, the upper one much smaller, yellow, sometimes fading to pink; stamens 2, free, with filaments mm long, staminodes 8, with filaments 3-6 mm long; ovary superior, 5-6 mm long, 1-celled, pubescent, style elongate, stigma small. Fruit an obovoid to oblong-ovoid pod 5-12 cm x cm, flattened, woody, 1-2- seeded. Seeds ellipsoid to globose, somewhat compressed, cm x 1-2 cm, chestnutbrown to black. Tylosema comprises 5 species and occurs in southern and eastern Africa. Some taxonomists do not consider Tylosema a separate genus, but include it in Bauhinia. Tylosema fassoglense is extremely variable, especially in its indumentum, leaf size and inflorescence size. Growth of Tylosema fassoglense is rapid, with the shoots growing up to 5 cm per day. In southern Africa Tylosema fassoglense flowers from October to March. Regeneration after fire is rapid. Tylosema fassoglense does not form root nodules and relies on soil nitrogen. Ecology Tylosema fassoglense occurs up to 2100 m altitude in woodland and grassland, sometimes in cultivated areas. It grows well on poor, sandy soils, but is also found on rocky or clay soils. It is moderately tolerant to flooding and drought. Management Tylosema fassoglense is collected from the wild. Fresh tuber weights up to 78 kg have been recorded. To prepare porridge from the tuber, it is scraped clean, then grated, crushed or pounded, and ground into a fine meal which is cooked. Genetic resources and breeding No substantial germplasm collections of Tylosema fassoglense are known to exist. The Plant Genetic Resources Unit of the Agricultural Research Council, Pretoria, South Africa, has 1 accession. Tylosema fassoglense is considered neither rare nor threatened. Prospects Tylosema fassoglense has interesting properties, such as tolerance of low soil fertility and drought, seeds with high levels of protein and fat, and tuberous roots storing water. Therefore, research into the potential of this plant and its possible cultivation is certainly justified. Major references Brenan, 1967; Castro et al, 2005; Dubois et al., 1995; Dubois et al, 1994; Ross, Other references Fort, Jolad & Nelson, 2001; Grobbelaar & Clarke, 1975; Huxham et al., 1998; Lock, 1989; Malaisse & Parent, 1985; Neuwinger, 2000; Tabuti, Lye & Dhillion, 2003; Thulin, 1989a; van Wyk & Gericke, 2000; Watt & Breyer-Brandwijk, Authors M. Brink UROCHLOAMOSAMBICENSIS (Hack.) Dandy Protologue Journ. Bot. 69: 54 (1931). Family Poaceae (Gramineae) Chromosome number 2n 28, 30, 42 Vernacular names Sabi grass, common urochloa, bushveld signal grass (En). Origin and geographic distribution Urochloa mosambicensis is distributed from Kenya southwards to South Africa; it has been introduced as a pasture grass into many other tropical countries, including Ghana and Madagascar. It was introduced into Australia in the early 1900s and has become an important grass for the northern Australian beef industry. Uses In southern Africa the grain of Urochloa mosambicensis is commonly used as a cereal; the ground grain is made into porridge. Urochloa mosambicensis is a useful, droughtresistant, palatable pasture grass also suitable for hay making. It is planted as a pasture grass in East Africa, southern Africa, Madagascar, India, Sri Lanka and Australia. In South Africa it is sown to improve overgrazed pastures. In India it is used against soil erosion. In Australia it plays a role in mine site rehabilitation. Properties Young green leaves of Urochloa mosambicensis typically contain up to 2.5% N, 0.2% P and are 65-70% digestible. In the late wet season these values are 1.2%, 0.15% and 55-60%, respectively. Dry leaves and stems are much lower in quality and typically contain 0.5% N and 0.2% P. Information on the nutritional characteristics of the grain is not available. Botany Tufted or stoloniferous perennial grass up to 1.5 m tall; stem (culm) ascending, sometimes rooting at the lower nodes. Leaves alternate, simple and entire; leaf sheath silky pubescent; ligule a ciliate membrane; blade linear, 2-30 cm x 3-20 mm, pale to bright green, more or less hairy. Inflorescence composed of 2-20 racemes borne on a central axis 3-15 cm long; racemes (l-)2-9( 14) cm long,

190 192 CEREALS AND PULSES bearing solitary spikelets on a narrowly winged rachis. Spikelet ovate, mm x mm, glabrous or hairy, acuminate, 2-flowered with lower floret male and upper bisexual; lower glume elliptical-oblong, shorter than spikelet, 3-veined, shiny, upper glume as long as the spikelet, 5-veined with cross-veins, granulöse to rugulose, with a mucro; lemma acuminate, leathery, 5-veined, with a mucro, palea shorter than lemma; stamens 3; ovary superior, with 2 plumose stigmas. Fruit a strongly flattened caryopsis (grain), pale buff or cream. Urochloa comprises about 12 species distributed in the Old World tropics, mainly in Africa. It is distinguished from the related Brachiaria by the shape and orientation of the spikelets but the boundary between the two genera is unclear due to a number of intermediate species. It has been proposed that Brachiaria be nearly completely reduced to Urochloa, which would increase the size of Urochloa to about 120 species, with a pantropical distribution. Within Urochloa the species are sometimes difficult to separate. Urochloa mosambicensis is the perennial counterpart of the annual Urochloa trichopus (Höchst.) Stapf, which does not possess dormant buds at the base. The grain of Urochloa brachyura (Hack.) Stapf, distributed in East and southern Africa, is eaten in Namibia; the plant is also grazed by animals. Seeds of Urochloa mosambicensis germinate early in the wet season and vegetative growth continues until soil water is exhausted. Flowering starts 3-4 weeks after the start of the rainy season and continues until growth ceases. Seed matures in 3-4 weeks. Leaves live for 5-25 weeks depending mainly on water supply. Plants are often short-lived (3-4 years). Urochloa mosambicensis is an obligate apomict. It follows the C4 photosynthetic pathway. Ecology In its natural habitat Urochloa mosambicensis occurs up to 1600 m altitude in regions with an average annual rainfall of ( 1600) mm, in savanna woodland and open grassland, often in disturbed or overgrazed locations (e.g. fallow land, roadsides). It grows in a wide range of soils, but prefers lighter, more fertile soils. In northern Australia it becomes dominant after fires. Management The grains of Urochloa mosambicensis are mostly collected from the wild, but sometimes plants are grown in gardens alongside maize. The 1000-seed weight is g. Fresh seed has dormancy, which breaks down after 9-12 months storage. Dormancy can be broken by hammer-milling, destroying the hard lemma. In India Urochloa mosambicensis is also propagated vegetatively using rooted cuttings. In pastures a seed rate of 4 kg/ha is recommended, or 2 kg/ha when grown intercropped with other pasture plants. Urochloa mosambicensis does well in intercropping with leguminous pasture plants and is commonly grown together with Stylosanthes spp. To obtain the grain, the inflorescences are picked when still slightly green and spread out in the sun to dry. When dry, the grains are easily rubbed from the stalks; they are ground. Grain yields of kg/ha per year have been recorded from Australia. In pastures dry matter yields of 1 8 t/ha per year are produced. Genetic resources and breeding The largest germplasm collections of Urochloa mosambicensis are held in Australia (Australian Tropical Crops & Forages Genetic Resources Centre, Biloela, Queensland, 73 accessions, mainly from African countries; CSIRO Townsville Division of Tropical Crops and Pastures, Townsville, Queensland, 63 accessions). In Africa 18 accessions are held in South Africa (Grassland Research Centre, Department of Agricultural Development, Pretoria), 7 accessions in Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa) and 7 accessions in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu). In view of its wide distribution and abundance, Urochloa mosambicensis is not threatened by genetic erosion. The collection held in Biloela has been investigated for a range of morphological and agronomical attributes, and considerable variation was found in time to maturity, stolon development, plant height and yield. Cultivars of Urochloa mosambicensis have been registered in Australia, e.g. 'Nixon' and 'Saraji'. Prospects Urochloa mosambicensis is a useful wild cereal in southern Africa, but it has more potential as a pasture grass for semi-arid tropical regions. Investigations are needed to assess the nutritional quality of the grains. Major references Burkill, 1994; Clayton, 1989; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Mclvor, 1992; Pengelly & Eagles, Other references Bogdan, 1977; Clayton & Renvoize, 1982; FAO, undated; Gibbs Russell et al., 1990; Mackay, 1974; Prakash & Uniyal, 1980; van Wyk & Gericke, 2000; Veldkamp, 1996a. Authors M. Brink

191 UROCHLOA 193 UEOCHLOA TRICHOPUS (Höchst.) Stapf Protologue Oliv., Fl. trop. Afr. 9(4): 589 (1920). Family Poaceae (Gramineae) Chromosome number 2n =14, 28 Origin and geographic distribution Urochloa trichopus is distributed in the more dry regions throughout tropical Africa. It also occurs in Yemen and has been introduced into Brazil and India. Uses The grain of Urochloa trichopus is sometimes gathered for food, e.g. in Kordofan (Sudan), Tanzania, Botswana and Zimbabwe. In Botswana it is ground into flour, which may be cooked with water, milk or melon juice or made into cake; it is also used for making beer. Urochloa trichopus is valued as a fodder in semi-arid regions; in Brazil and India it is a forage grass. Properties The fodder value of Urochloa trichopus plants in the Sahel is: crude protein 10.7%, crude fibre 28.5%, crude fat 1.4%, nitrogen-free extractives 45.2%, P 0.19%, K 4.69%, Ca 0.38%, Mg 0.37% and Na 0.02%. In Botswana the crude protein content of Urochloa trichopus ranges from 6.2% in the dry season (July) to 10.4% in the rainy season (January), and the dry matter digestibility ranges from 41% in July to 57% in January. Information on the nutritional characteristics of the grain is not available. Botany Coarse, tufted annual grass up to 1.7 m tall; stem (culm) geniculately ascending, often rooting at the lower nodes. Leaves alternate, simple and entire; leaf sheath glabrous to slightly pubescent; ligule a ciliate membrane; blade linear, 5-30 cm x 5-20 mm, acuminate, glabrous or hairy. Inflorescence composed of 3-20 racemes borne on a central axis 4 20 cm long; racemes 1-14 cm long, bearing solitary spikelets on a narrowly winged rachis. Spikelet ovate, mm long, glabrous or less often hairy, acuminate, 2-flowered with lower floret male and upper bisexual; lower glume elliptical-oblong, slightly shorter than spikelet, 3- veined, upper glume as long as the spikelet, 5(- 7)-veined with cross-veins; lemma acuminate, leathery, 5-veined, with a mucro; palea shorter than lemma; stamens 3; ovary superior, with 2 plumose stigmas. Fruit a strongly flattened caryopsis (grain). Urochloa comprises about 12 species distributed in theold World tropics, mainly in Africa. It is distinguished from the related Brachiaria by the shape and orientation of the spikelets but the boundary between the two genera is unclear due to a number of intermediate species. It has been proposed that Brachiaria be nearly completely reduced to Urochloa, which would increase the size of Urochloa to about 120 species, with a pantropical distribution. Within Urochloa the species are sometimes difficult to separate. Urochloa trichopus is the annual counterpart of the perennial Urochloa mosambicensis (Hack.) Dandy, which possesses dormant buds at the base. Ecology Urochloa trichopus occurs from sealevel up to 1500 m altitude in semi-arid climates, in grassland and savanna woodland; also in disturbed locations and as an arable weed. Management Urochloa trichopus is collected from the wild. In Botswana stored grain is attacked by weevils, ants and rats, but it generally stores well. In Botswana the grain is considered difficult to thresh and pound. Urochloa trichopus is considered a weed in Ethiopia. Genetic resources and breeding The International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, holds 5 accessions of Urochloa trichopus (3 from Ethiopia; 2 from Mali). Three accessions from Ethiopia are held at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia; 2 accessions from Tanzania in the Australian Tropical Crops & Forages Genetic Resources Centre, Biloela, Queensland. In view of its wide distribution, Urochloa trichopus is not threatened by genetic erosion. Prospects Urochloa trichopus is a useful source of food and fodder in semi-arid regions of tropical Africa, but is unlikely to increase in importance. For use as a cereal, the small grain size and difficulty in processing are considered serious limitations. Its role as a pasture grass will probably remain modest compared to that of its perennial and more persistent counterpart Urochloa mosambicensis. Major references Burkill, 1994; Clayton & Renvoize, 1982; Gibbs Russell et al., 1990; Modiakgotla et al, 1999; Phillips, Other references Bartha, 1970; Clayton, 1972; Clayton, 1989; Cope, 1995; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Longhi-Wagner & de Oliveira, 2002; Pratchett, 1983; Trouin, 1970; Veldkamp, 1996a. Authors M. Brink

192 194 CEREALS AND PULSES VATOVAEAPSEUDOLABLAB (Harms) J.B.Gillett Protologue Kew Bull. 20(1): 104 (1966). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Origin and geographic distribution Vatovaea pseudolablab is found wild in the drier parts of Sudan, Ethiopia, Somalia, Kenya, Uganda and Tanzania; also in Yemen and Oman. Uses The seeds of Vatovaea pseudolablab are eaten either raw or after boiling or roasting. Immature pods, flowers and leaves are eaten raw or cooked as a vegetable. The tuberous and juicy roots are edible and are consumed raw or after boiling or roasting. They are sometimes eaten as a snack, especially after roasting; they are also used as emergency food and as a source of water. Flour made from the roots is mixed with sorghum flour to prepare a stiff porridge. It is normally stored and used in lean periods. Farmers grow and consume Vatovaea pseudolablab commonly, but during food shortages more people rely on it for their daily food. The plant is eaten by cattle, goats, sheep, camels and donkeys. The root fibres are made into rope, hats and fly whisks. Properties The tuberous roots of Vatovaea pseudolablab are fibrous and contain much juice; they have a pleasant, sweet taste even when eaten raw. Botany Liana or shrub up to 1.5( 3) m tall; stem branched, glabrous to sparsely pubescent; roots tuberous. Leaves alternate, 3-foliolate; stipules oblong, c. 3.5 mm x 1.5 mm; petiole up to 6 cm long, ribbed, rachis up to 2 cm long; stipels small; petiolules 1-2 mm long; leaflets ovate to narrowly ovate-rhomboid, up to 8 cm x 6.5 cm, sometimes slightly 3-lobed, glabrous to sparsely pubescent. Inflorescence an axillary false raceme up to 50 cm long, pubescent, many-flowered; peduncle 6-21 cm long; bracts up to 2 mm long. Flowers bisexual, papilionaceous; pedicel c. 3 mm long; calyx c. 5 mm long, 5-lobed, 2-lipped, the lower 3 lobes roundedtriangular, the upper 2 lobes united; corolla greenish purple, standard 1-2 cm x cm, emarginate, with 2 appendages near the base, wings with a long narrow spur, keel incurved; stamens 10, 9 fused and 1 free; ovary superior, linear, 1-celled, style long, incurved, usually hairy inside towards the apex and with a reflexed appendage above the stigma. Fruit a linear-oblong pod cm x cm, curved, flattened, widening towards the apex, dehiscent, at first silky pubescent, later glabrescent, up to 8-seeded. Seeds almost globose to irregularly ellipsoid or squarish, mm x mm x mm, brown, sometimes speckled with black. Vatovaea comprises a single species. Although Vatovaea pseudolablab becomes woody, plants may already flower when still quite herbaceous; they are basically self-pollinating. Ecology Vatovaea pseudolablab is found up to 1500 m altitude in dry grassland or bushland in regions with an annual rainfall of mm, often along lava or drainage lines, occasionally in seasonally wet grassland on clay. Management Vatovaea pseudolablab is commonly collected from the wild, but only occasionally sown, e.g. in Kenya. In Ethiopia it is semi-domesticated by Konso farmers, who keep it in their fields intercropped with other food plants. Vatovaea pseudolablab can be propagated by seed. The tuberous roots can be dug out any time of the year; they are best gathered when the foliage has died back. Flour is produced from the roots by peeling, chopping, drying and grinding. Genetic resources and breeding Vatovaea pseudolablab populations are dwindling in East Africa and in the Arabian Peninsula because it is a popular food and fodder. Its genetic pool is likely to shrink fast if no action is taken. Two accessions of Vatovaea pseudolablab are kept in Ethiopia at the International Livestock Research Institute (ILRI), Addis Ababa. Prospects Vatovaea pseudolablab is a useful multipurpose plant for dry regions and its potential seems worthwhile exploiting. It is recommended to start collecting and evaluating germplasm and to test accessions for their performance in the field. Promising material should be multiplied further. Furthermore, investigations should be carried out on the agronomy of the plant and its nutritional properties. Major references Beentje, 1994; Gillett et al, 1971; Maundu, Ngugi & Kabuye, 1999; Schippers, 2000; Thulin, Other references African Studies Center, undated; Gillett, 1966; Huxham et al., 1998; ILDIS, 2002; IPGRI, undated; Maundu, 1997; Morgan, 1981; Thulin, 1989a; Thulin, 1989b. Authors M. Brink

193 VICIA 195 VICIA FABA L. Protologue Sp. pi. 2: 737 (1753). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n 12 Vernacular names Faba bean, broad bean, horse bean, field bean, tick bean (En). Fève, fève de(s) marais, fèverole, fèvette, gourgane (Fr). Faveira, fava (Po). Origin and geographic distribution Faba bean is only known in cultivation. Its centre of origin and domestication is probably in western Asia, from where it spread into Europe, Africa and central Asia. Ethiopia and Afghanistan are considered secondary centres of diversity. Faba bean domestication occurred between 7000 and 4000 BC, and by the 3 rd millennium BC it was widely distributed throughout the Mediterranean region. The evolution of the large-seeded type was much later (around 500 AD), and may have occurred in western Asia and in the Mediterranean region. Faba bean was probably not grown to any extent in Japan and China before 1200 AD, nor in the Americas before the arrival of the Spaniards. Nowadays, faba bean is widely grown in temperate and subtropical regions and at higher altitudes in the tropics. In tropical Africa it is mainly found in East Africa, especially in Sudan and Ethiopia. Uses Faba bean is grown as a field crop for the dry mature seeds and as a garden crop for the immature seeds or pods. In Ethiopia, Mediterranean countries, the Middle East and China the dry mature seeds are widely used as food, and in many countries the green immature seeds are boiled or eaten raw as vegetable. In Mediterranean countries and in India whole Vicia faba -planted immature pods are eaten. In Ethiopia and Eritrea main dishes include 'shiro wot' (hulled seeds ground and made into sauce), 'kik wot' (hulled and split seeds boiled and made into sauce), and 'ful' (hulled and boiled seeds, spiced and minced with butter). Snacks include 'eshet' (fresh green seeds eaten raw or roasted), 'kolo' (roasted dry seeds), 'nifro' (boiled dry or fresh green seeds), 'gunkul' (seeds soaked, sprouted and roasted), 'ashuk' (seeds roasted first and then soaked), and 'endushdush' (seeds soaked first and then roasted). Throughout the Arab world faba bean seeds are consumed minced with onion, garlic and herbs, and eaten for breakfast as 'ful medames'. Stewed seeds are eaten at any time of the day; seeds made into a paste are often used as a sandwich filling. Mature seeds and vegetative parts of faba bean serve as concentrate, hay and silage for domestic animals. The straw is used as fuel for cooking in Ethiopia. The stems and leaves are used as green manure, e.g. in China. In China seeds and vegetative parts have a wide range of medicinal applications. In Europe the inside of the green pods is rubbed on warts to remove them. Production and international trade According to FAO statistics the world production of dry faba bean seeds in amounted to 3.9 million t/year from 2.6 million ha. The main producing countries are China (1.9 million t/year from 1.2 million ha), Ethiopia (405,000 t/year from 370,000 ha), Egypt (396,000 t/year from 134,000 ha) and Australia (242,000 t/year from 164,000 ha). The annual production in sub-sahara Africa in was estimated at 510,000 t, almost entirely from Ethiopia (405,000 t) and Sudan (100,000 t). The annual world production of dry faba bean seeds declined from about 5 million t (from 5 million ha) in the early 1960s to about 4 million t (from 2.7 million ha) in the early 2000s. The reduction in area under cultivation in China from about 3.5 million ha in the early 1960s to about 1.25 million ha in the early 2000s accounted for the largest share of the reduction in production. In contrast, the annual production in sub- Sahara Africa increased during the same period from 230,000 t (250,000 ha) to 540,000 t (450,000 ha). The world production of green faba bean seeds in was estimated at 940,000 t/year from 2.6 million ha, with Algeria (118,000 t/year), China (114,000 t/year) and Morocco (112,000 t/year) as the largest producers; the production of green faba bean seeds in tropical Africa is negligible. World exports of dry faba bean seeds in 1998-

194 196 CEREALS AND PULSES 2002 amounted to 475,000 t. The main exporting countries were Australia (201,000 t), the United Kingdom (114,000 t), China (63,000 t) and France (53,000 t). The main importers in this period were Egypt (197,000 t), Italy (169,000 t) and Spain (52,000 t). The exports from African countries are negligible. Properties The composition of raw mature faba bean seeds per 100 g edible portion is: water 11.0 g, energy 1425 kj (340 kcal), protein 26.1 g, fat 1.5 g, carbohydrate 58.3 g, dietary fibre 25.0 g, Ca 103 mg, Mg 192 mg, P 421 mg, Fe 6.7 mg, Zn 3.1 mg, vitamin A 53 IU, thiamin 0.56 mg, riboflavin 0.33 mg, niacin 2.8 mg, vitamin Ik 0.37 mg, folate 423 (ig and ascorbic acid 1.4 mg. The essential amino acid composition per 100 g edible portion is: tryptophan 247 mg, lysine 1671 mg, methionine 213 mg, phenylalanine 1103 mg, threonine 928 mg, valine 1161 mg, leucine 1964 mg and isoleucine 1053 mg. The principal fatty acids per 100 g edible portion are: linoleic acid 581 mg, oleic acid 297 mg and palmitic acid 204 mg (USDA, 2004). In certain persons genetically predisposed, living mainly in the Mediterranean area, consumption of faba bean seeds, particularly immature ones, and even the inhalation of pollen, results in 'favism', a kind of haemolytic anaemia resulting from the accumulation of ß- glycosidase (vicine and convicine) and their aglycones in individuals deficient in the enzyme glucose-6-phosphate dehydrogenase in their red blood cells. Soaking before cooking inactivates the toxic compounds. Other antinutritional factors in faba bean seeds include trypsin inhibitors, lectins (haemagglutinins), tannins, oligosaccharides and phytate. Faba bean seeds have lipid-lowering effects in humans and rats. Proteins isolated from the seed have shown antioxidative activity, whereas the lectin agglutinin may slow the progression of colon cancer. Faba bean straw is a good feed with high protein content (5-20%) and digestibility (50% of the dry matter). The high tannin content of the seeds (up to 9%) results in a bitter taste when they are fed raw to animals, but cultivars have been developed with low tannin content (1%) and high digestibility. Description Erect, robust, stiff, glabrous, annual herb up to 2 m tall; stem stout, square, hollow with one or more basal branches; taproot well-developed, with strong lateral roots. Leaves alternate, paripinnate, with 2-6 leaflets, without tendril, but rachis ending in a short acumen; stipules conspicuous, widely Vicia faba - 1, flowering and fruiting branch; 2, seeds. Source: PROSEA varying in shape, toothed; leaflets ovate to elliptical, (3-)4-8(-10) cm x l-2(-4) cm, entire. Inflorescence an axillary, sessile, short raceme, 1-6-flowered. Flowers bisexual, papilionaceous, almost sessile; calyx campanulate, 5-lobed, tube c. 7 mm long, lobes almost equal, narrowly triangular, 2 8 mm long; corolla white, marked by a dark brown blotch, fragrant, standard broadly ovate, c. 2.5 cm x 1.5 cm, approaching the keel, wings oblong-ovate, c. 2.5 cm x 0.5 cm, keel c. 1.5 x 0.5 cm; stamens 10, 9 united and 1 free, c. 15 mm long, anthers ellipsoid to ovoid, about 1 mm long, dark brown; ovary superior, sessile or nearly so, very slender, compressed, c. 1.5 cm long, style abruptly upturned, c. 3 mm long, with a tuft of hairs near the glandular-papillate stigma. Fruit a narrowly oblong, cylindrical to flattened pod, (3-)5-10(-30) cm x l-1.5(-3) cm, bulging over the seeds, sparsely pubescent when mature, beaked, 2-6-seeded. Seeds ovoid to oblong, compressed, 1 3 cm in diameter, brown, reddish or green; hilum narrowly oblong. Seedling with hypogeal germination. Other botanical information Vicia comprises about 120 species, mainly in the temperate regions of the northern hemisphere and

195 VICIA 197 South America, with a few species in Africa. Vicia faba is unique in the genus: it has larger but fewer chromosomes and the greatest amount of DNA content (around 13,000 Mbp). No other Vicia could successfully be crossed with Vicia faba despite many attempts. Morphometry and seed-protein electrophoresis studies have shown marked differences between Vicia faba and wild relatives {Vicia narbonensis L., Vicia galilaea Plitmann & Zohary and Vicia hyaeniscyamus Mouterde). The infraspecific taxonomy of Vicia faba is confusing. Several varieties have been distinguished, based on the shape and size of the seeds. Cultivars with small and rounded seeds are often called tick bean, those with intermediate seed size horse bean, and those with large and flat seeds broad bean. However, there is no discontinuity in seed size between the groups, and they can be freely crossed. Arbitrarily, small-seeded types have been recognized as those with a 1000-seed weight of less than 700 g, medium-seeded types with g, and large-seeded types with more than 1200 g. Vicia sativa L. is widely cultivated as a forage. Its seeds, young stems and leaves are recorded as being used for human consumption in Ethiopia and the Caucasus. However, the seeds and hay can have toxic effects (HCN-poisoning due to the cyanogenic glycoside vicianine; antinutritional effects of ß-cyanoalanine). The seeds of Vicia villosa Roth, cultivated for fodder in East Africa, and Vicia paucifolia Baker are also said to be collected and eaten. Vicia monantha Retz. (bard vetch) has at least in former times been grown in oases in the Sahara. However, the seeds of many Vicia species, including Vicia villosa and Vicia monantha, are known to contain canavanine, a toxic arginine analogue. Growth and development Five principal stages have been distinguished in a key for faba bean development: germination and emergence, vegetative development, reproductive development, pod senescence and stem senescence. Vegetative development continues after reproductive development has started, thus both stages run concurrently. The onset of flowering strongly depends on environmental conditions (temperature, photoperiod), and may range from 1 month to 7-8 months. The longer durations occur in winter-sown crops in temperate regions. Flowering starts, on average, at node 7 and continues over as many as 20 nodes. Faba bean pollination habit is intermediate between self- and cross-pollinating. Cross-pollination rates up to 92% have been recorded, but they are mostly between 20% and 50%. Insects facilitate cross-pollination. The duration of the growth cycle varies from 3 months (Sudan, Canada) to 11 months (northwestern Europe). In Ethiopia the growth cycle is 3-7 months. Faba bean is effectively nodulated by Rhizobium leguminosarum. Ecology Faba bean is grown in temperate regions, as a winter crop in the subtropics, and as a high-altitude crop in the tropics. It is not suited to the lowland tropics, where it may flower well but usually does not produce pods. A mean daily temperature around 13 C is optimal for growth. In Ethiopia faba bean is grown at m altitude, but mostly at m. Rust is the major production constraint below 1800 m, and frost above 3000 m. Faba bean requires an annual rainfall of mm, of which more than 60% during the growing period. Long photoperiods reduce the time to flowering and the position of the first flowering node, e.g. in northern European cultivars, but under field conditions daylengthneutrality is often observed. Faba bean prefers well-drained, almost neutral soils (ph ), with moderate fertility. It hardly tolerates waterlogging or drought. Propagation and planting Faba bean is propagated by seed. The 1000-seed weight is g. Faba bean does not require a fine seedbed, but the land should be ploughed to a loose seedbed. The crop is broadcast or planted in rows; in mechanized agriculture drilling is common. The planting depth is 2 5 cm. Seed rates vary widely; higher rates are required in the cool high-altitude areas of the tropics, where crop growth is slower than in warm midaltitude areas. Seed rates up to kg/ha are recommended in Ethiopia, kg/ha in Sudan and kg/ha in Egypt. Spacings vary from place to place. In Ethiopia 40 cm between rows and 5 cm between plants is recommended. In Sudan a distance between rows of cm is recommended, with 5-20 cm within rows and 1-3 plants per pocket. However, small-scale farmers in Sudan, Ethiopia and Eritrea practice broadcasting. In Egypt planting on ridges is the usual practice. In case of sowing on both sides of the ridges, a spacing of 60 cm between ridges and cm between pockets with 2 seeds/pocket is optimal. In Ethiopia common sowing dates are mid-june in mid-altitude areas and late June to early July in high-altitude areas. Planting in Egypt and

196 198 CEREALS AND PULSES Sudan may start in mid-october and proceed until late November. Faba bean is grown as a sole crop or in intercropping, e.g. with pea in Ethiopia, sugar cane in Egypt and various crops (wheat, rape, cotton and barley) in China. Management Faba bean is sensitive to weed competition and rigorous control of weeds is needed from 3-8 weeks after seedling emergence. Weeds are controlled manually or with herbicides. One or 2 manual weedings may be required, the first one at 3 4 weeks after emergence, the second one at 6 8 weeks. Faba bean is grown under irrigation in Egypt and Sudan, whereas in Ethiopia and Eritrea it is grown entirely under rainfed conditions. Nitrogen application may not be necessary where Rhizobium leguminosarum is present, but in some countries kg N/ha is applied as a starter. Atmospheric nitrogen fixation rates of kg N per ha per year (on average around 200 kg) have been recorded for faba bean. In areas where the bacteria are absent, inoculation of the seed with bacteria is an option. Most small-scale farmers in Ethiopia do not apply chemical fertilizers. Experiments in Ethiopia have shown little or no response to N- fertilization, but P-application often leads to significant yield increases. In Sudan faba bean is not normally responsive to application of N and K, due to the presence of N-fixing bacteria and high inherent K in the soil. However, P is limiting, as the soils are alkaline (ph>8) and only a little P is available for the crop. Hence, placement of P close to the root system is recommended. In Egypt, 36 kg N and 30 kg P per ha is applied for traditional cultivars (yielding about 2.5 t/ha), whereas for improved cultivars (yielding up to 5 t/ha) additional top dressings (at 40 and 70 days after sowing) of 50 kg K per ha are recommended as well as a micronutrient spray of 60 g Zn, 40 g Mn and 20 g Fe per ha. Faba bean plays an important role in soil fertility management as a rotation crop; it is often grown in rotation with cereals, especially with wheat or barley. Diseases and pests The most important fungal diseases of faba bean are chocolate spot {Botrytis fabae and Botrytis cinerea), ascochyta blight (Didymella fabae; synonym Ascochyta fabae), rust (Uromyces viciae-fabae), and black root rot (Fusarium spp.). Chocolate spot and rust have been recorded as causing up to 50% yield loss in Egypt. Suggested control measures include use of resistant cultivars, cultural practices (crop rotation, drainage, disease-free seed, burning of crop residues) and fungicides. Important virus diseases of faba bean are bean yellow mosaic virus (BYMV), bean leaf roll virus (BLRV) and broad bean stain virus (BBSV). Root-knot nematodes (Meloidogyne spp.), stem nematodes (Ditylenchus dipsaci) and root-lesion nematodes (Pratylenchus spp.) also affect faba bean. Aphids (Aphis craccivora, Aphis fabae and Acyrthosiphon pisum) are major insect pests of faba bean, e.g. in Sudan and Egypt. Other insect pests are the leaf weevil (Sitona lineatus), the pod borer (Helicoverpa armigera), the root nodule weevil (Sitona amurensis), cutworms (Agrotis spp.), the leaf miner (Liriomyza congesta) and the lesser armyworm (Spodoptera exigua). Bruchids (Bruchus and Callosobruchus spp.) are major storage pests, e.g. in Ethiopia. In Europe, the Middle East and northern Africa the parasitic herb Orobanche crenata Forssk. (bean broomrape) is a critical problem. No practical control measure is available. Harvesting Harvesting of faba bean is done before full physiological maturity, because late harvesting may result in pod shattering and rotting, particularly when rain is encountered. The appropriate stage is when the leaves and the pods dry out and the seed moisture content is reduced to 16 18%. Faba bean can be combine harvested, but in tropical Africa manual harvesting is the common practice. Plants are hand-pulled or cut using a small knife or sickle. Harvesting is usually done in the early morning or late afternoon to reduce losses from shattering. The harvested plants are gathered into small heaps and left in the field for a few days to dry. Then they are transported to a threshing ground. Yield The average seed yield of faba bean in Africa (1.3 t ha/ha) is below world average (1.5 t/ha), while the average yields obtained in Asia (1.7 t/ha) and Europe (2.2 t/ha) are higher. Exceptionally high yields are obtained in Egypt and Sudan where the crop is irrigated (3.0 and 2.3 t/ha, respectively). Handling after harvest Threshing of faba bean is traditionally done by beating the plants with sticks or by trampling animals. Seeds should be stored under dry and cool conditions, free of pests and prevented from absorbing moisture. Cleaning seeds and storage structures before storing is important. Seeds with a moisture content of 11-14% can be stored for 2-7 years at temperatures of 5-10 C and for1 4 years at C. Genetic resources Over 25,000 faba bean accessions are currently conserved in different

197 VICIA 199 countries. The International Center for Agricultural Research in the Dry Areas (ICARDA) in Aleppo, Syria, holds about 10,700 faba bean accessions and 5900 accessions of wild Vicia species. Other important collections are kept in China (Institute of Crop Germplasm Resources (CAAS), Beijing; 3800 accessions) and Australia (Australian Temperate Field Crops Collection, Horsham; 2200 accessions). The largest collection of faba bean germplasm in Africa (2000 accessions) is kept at the Institute of Biodiversity Conservation (IBC), Addis Ababa, Ethiopia. The collections include sources for multiple disease resistance, wild and primitive forms, lines carrying structural mutations, breeding lines and cultivars of special interest. The worldwide diversity available in faba bean has not yet been adequately sampled, and the available collections have not sufficiently been characterized. Faba bean shows orthodox seed storage behaviour. Breeding High yield and resistance/tolerance to both biotic and abiotic stresses are the prime objectives across faba bean breeding programmes. Some breeding efforts to improve the yield potential of conventional indeterminate types have been promising. Sources of resistance to chocolate spot, ascochyta blight and rust identified at ICARDA have been used in many national faba bean breeding programmes. Australia has released cultivars resistant to chocolate spot and ascochyta blight. In Ethiopia the cultivars 'Wayu' and 'Selale' with resistance to black root rot disease on waterlogged Vertisols have recently been released. More than 10 cultivars have been released for different agro-ecological conditions in Ethiopia and Egypt, and 7 in Sudan. Recently, export-quality seed (large seed size) has attracted attention in breeding programmes in China and Ethiopia. Attempts to develop hybrid faba bean cultivars have not yet been successful because of lack of an effective male sterility system. Efforts to change the indeterminate growth habit into determinate types with increased yield through mutation breeding have also not been successful so far. In-vitro callus formation and plant regeneration have been achieved with hypocotyl, cotyledon and embryo expiants. Stably transformed faba bean lines have been produced using an Agrobacterium-mediated gene transfer system. Genetic linkage maps of the faba bean genome have been constructed based on morphological markers, isozymes, RAPDs, seed protein genes and microsatellites. A gene controlling resistance to rust has been tagged, and quantitative trait loci associated with seed weight, resistance to ascochyta blight and resistance to bean broomrape have been located. The presence of vicine and convicine in faba bean seeds is controlled by a single recessive gene that reduces their content 20-fold. However, the same gene increases susceptibility to pathogens and parasites. Two recessive genes eliminate tannin production in faba bean. Prospects Faba bean productivity is far below the potential in many countries of tropical Africa because of the biological limitations of the traditional cultivars and poor management practices. However, faba bean will remain an important crop in parts of tropical Africa. Export demand is strong and regional markets are emerging, e.g. between Ethiopia (exporter) and Sudan and Egypt (importers). In addition to the needs emanating from the physical environment, farming systems and local consumers' preferences, export qualities and standards also deserve priority in research. Efforts are being undertaken in some countries, e.g. China, to develop new highervalue types superior in colour, smell and taste, and these efforts, coupled with the wealth of genetic diversity available, might result in new opportunities. Major references Enneking, 1995; Hawtin & Webb (Editors), 1982; Hebblethwaite (Editor), 1983; Jansen, 1989e; Jellis, Bond & Boulton, 1998; Knight (Editor), 2000; Knott, 1990; Lang et al., 1993; Muehlbauer & Kaiser (Editors), 1994; Thulin, 1989a. Other references Bond, 1995; Bond et al., 1985; Böttinger et al, 2001; Ghizaw et al., 1999; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; ILDIS, 2002; Kay, 1979; Madar & Stark, 2002; Maxted, 1995; McPhee & Muehlbauer, 2002; Polhill, 1990; Purseglove, 1968; Roman et al., 2004; Singh & Saxena (Editors), 1993; Smartt, 1976; Summerfield (Editor), 1988; Tindall, 1983; USDA, 2004; Westphal, 1974; Zemede Asfaw & Mesfin Tadesse, Sources of illustration Jansen, 1989e. Authors M. Jarso &G. Keneni

198 200 CEREALS AND PULSES VICIA HIESUTA (L.) Gray Protologue Nat. arr. Brit. pi. 2: 614 (1821). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n - 14 Vernacular names Hairy tare, tiny vetch, hairy vetch (En). Ers velu, vesceron, vesce hérissée (Fr). Cigerâo (Po). Origin and geographic distribution Vicia hirsuta is widely distributed in Europe, Asia and Africa. In Africa it is native from northern Africa through DR Congo and East Africa to Angola and South Africa. It is often introduced and naturalized elsewhere, e.g. in the Indian Ocean islands. Vicia hirsuta is sometimes cultivated as a pulse or as a fodder crop in India and was formerly grown in eastern Europe. Uses The seeds of Vicia hirsuta are collected from the wild and eaten cooked or roasted in Ethiopia. They were eaten as a famine food in Europe and Asia. The leaves and shoots are used as a vegetable in Ethiopia. Vicia hirsuta is also a forage. Properties The seeds of Vicia hirsuta contain trypsin inhibitors, but heating for 20 minutes at 100 C at ph 2.0 reduces the trypsin inhibiting activity by 50%. The seeds also contain the non-protein amino acid canavanine, a toxic arginine analogue. Botany Trailing or climbing annual herb up to 90 cm tall; stem glabrous or thinly hairy. Leaves alternate, paripinnate, with 6-20 leaflets; stipules semisagittate, 2-15 mm x mm, the upper part entire, the lower deeply divided into 2-3 filiform segments; petiole 0 5(-10) mm long, rachis usually terminating in a branched tendril; petiolules c. 0.5 mm long; leaflets linear or narrowly oblong, 4-20 mm x 1-3 mm, almost glabrous. Inflorescence an axillary raceme 2 6 cm long, 2 7-flowered; peduncle cm long. Flowers bisexual, papilionaceous; pedicel mm long; calyx 5- lobed, pubescent, with tube 1( 2.5) mm long and lobes mm long; corolla white, rose or pale blue, standard obovate, 3-5 mm x 2 mm, wings and keel slightly shorter; stamens 10, 9 fused and 1 free; ovary superior, hairy, 1- celled, style short, curved, stigma small. Fruit an oblong pod 6-10 mm x 3-4 mm, compressed, pilose, dehiscent, (1 )2( 3)-seeded. Seeds globose, 2 3 mm in diameter, dark brown or mottled pale and dark brown. Seedling with hypogeal germination. Vicia comprises about 120 species, mainly in the temperate regions of the northern hemisphere and South America, with a few species in Africa. Vicia hirsuta is effectively nodulated by Rhizobium leguminosarum. Ecology In East Africa Vicia hirsuta is found in grassland, scrub, forest margins and lava plains at m altitude. Vicia hirsuta is a long-day plant. In many countries it is considered a weed. Genetic resources and breeding The largest germplasm collections of Vicia hirsuta are maintained at the International Centre for Agricultural Research in Dry Areas (ICARDA), Aleppo, Syria (39 accessions) and the International Centre for Underutilised Crops, University of Southampton, Southampton, United Kingdom (32 accessions). In tropical Africa some accessions are held in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 9 accessions) and Ethiopia (International Livestock Research Institute (ILRI), Addis Ababa, 5 accessions). In view of its wide distribution and unspecific habitat requirements Vicia hirsuta is not threatened with genetic erosion. Prospects Vicia hirsuta is only occasionally used as a pulse. It is unlikely that its importance as a food crop will increase in the future. Still, more information would be useful on the nutritional quality of the seed and appropriate processing methods to eliminate its toxic compounds. Major references Enneking, 1995; Gillett et al., 1971; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Thulin, 1983; Zemede Asfaw & Mesfin Tadesse, Other references Bohra & Sharma, 1981; Holm, Pancho & Herberger, 1979; ILDIS, 2005; Mutch & Young, 2004; Polhill, 1990; Sharma & Lavania, 1977; Southon et al., 1994; Thulin, 1989a. Authors M. Brink VIGNAACONITIFOLIA (Jacq.) Maréchal Protologue Bull. Jard. Bot. Belg. 39(2): 160 (1969). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number In = 22 Synonyms Phaseolus aconitifolius Jacq. (1768). Vernacular names Moth bean, moth gram, mat bean, dew bean, dew gram (En). Haricot mat, mat, haricot papillon (Fr).

199 VlGNA 201 Origin and geographic distribution Moth bean is native to India, Pakistan and Myanmar where it grows both wild and cultivated. It is also grown in other parts of Asia, Africa, the United States and Cuba. As a pulse it is mostly grown in India and Thailand; elsewhere it is mostly a forage, green manure or cover crop. In tropical Africa it has been recorded from Sudan, Eritrea, Somalia, Kenya and Botswana. Uses The ripe whole or split seeds of moth bean are eaten cooked or fried. Sprouted and cooked seeds are preferred as breakfast items in India whereas fried splits are consumed in the form of a ready to eat product. The seeds are sometimes ground into flour, which is mixed with other flours to make unleavened bread. The immature pods are sometimes eaten boiled as a vegetable. In India the pod walls and residues left after the preparation of dhal are fed to animals. Moth bean is also grown for green manure, forage and hay and as a cover crop. Seeds are used medicinally in diets to treat fevers; roots are said to be narcotic. Production and international trade In India moth bean is grown on 1.5 million ha producing annually about 0.4 million t of seed which is traded and consumed within the country. Worldwide moth bean is grown on about 2 million ha. Properties Mature, raw moth bean seeds contain per 100 g edible portion: water 9.7 g, energy 1435 kj (343 kcal), protein 22.9 g, fat 1.6 g, carbohydrate 61.5 g, Ca 150 mg, Mg 381 mg, P 489 mg, Fe 10.9 mg, Zn 1.9 mg, vitamin A 32 IU, thiamin 0.56 mg, riboflavin 0.09 mg, niacin 2.8 mg, vitamin Be 0.37 mg, folate 649 Hg and ascorbic acid 4.0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 147 mg, lysine 1248 mg, methionine 220 mg, phenylalanine 1028 mg, valine 734 mg, leucine 1541 mg and isoleucine 1138 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 485 mg, palmitic acid 313 mg, linolenic acid 265 mg, oleic acid 129 mg and stearic acid 51 mg (USDA, 2005). The protein has a lower digestibility than that of mung bean (Vigna radiata (L.) R.Wilczek). The digestibility of the starch and protein is considerably improved by processing treatments such as soaking, removal of the seed coat, germination and pressure cooking. Botany Annual, slender, hairy herb with short, angular, erect stem up to 40 cm tall and many prostrate branches up to 150 cm long. Leaves alternate, 3-foliolate; stipules lanceo- Vigna aconitifolia - 1, flowering branch; 2, infructescence; 3, seeds. Source: PROSEA late, c. 12 mm long, peltate; petiole 5-10 cm long, grooved; stipels small; leaflets 5-12 cm long, deeply divided into 3 5 narrow lobes. Inflorescence an axillary, head-like, dense false raceme; peduncle 5-10 cm long. Flowers bisexual, papilionaceous; pedicel 5-8 mm long; calyx campanulate, c. 2.5 mm long; corolla yellow, standard orbicular, up to 8 mm long, wings c. 6 mm long, keel sickle-shaped, c. 7 mm long; stamens 10, 9 united and 1 free; ovary superior, sessile, c. 4 mm long, style incurved. Fruit a cylindrical pod cm x 0.5 cm, brown, covered with short stiff hairs, 4 9-seeded. Seeds rectangular to cylindrical, 3 5 mm x mm, whitish green, yellow to brown, often mottled with black; hilum white, linear. Seedling with epigeal germination. Vigna comprises about 80 species and occurs throughout the tropics. Vigna aconitifolia belongs to subgenus Ceratotropis, which also includes Vigna radiata (L.) R.Wilczek (mung bean), Vigna umbellata (Thunb.) Ohwi & H.Ohashi (rice bean), Vigna mungo (L.) Hepper (black gram) and Vigna angularis (Willd.) Ohwi & H.Ohashi (adzuki bean). In India numerous landraces and cultivars of moth bean

200 202 CEREALS AND PULSES exist. For germination of moth bean a temperature of c C is optimal. Vegetative development starts slowly. Moth bean is predominantly selfpollinated and takes days after sowing to mature. It effectively nodulates with Bradyrhizobium strains from the cowpea crossinoculation group. Ecology In India moth bean is the most drought-resistant pulse crop and particularly cultivated in hot, arid to semi-arid regions. For optimum production it requires an average temperature of C, but it withstands daytime temperatures up to 45 C. In India moth bean is grown from sea-level up to an altitude of 1300 m. Moth bean thrives with a welldistributed annual rainfall of mm, but it is also grown successfully in areas with as low as mm annual rainfall. Even with as little as mm in 3-4 showers during the growing period, some yield can be obtained. Moth bean is a quantitative short-day plant, but day-neutral types are also known. It grows on many soil types but is particularly suitable for dry light sandy soils. It does not tolerate waterlogging. Some degree of salinity and a wide ph range (3.5-10) are tolerated. Management Moth bean is propagated by seed; the 1000-seed weight is g. It should be sown on a well-prepared seedbed. Moth bean is usually broadcast, at a seed rate of kg/ha when grown for seed as a sole crop and 7-34 kg/ha when grown for forage. When sown in rows the seed rate is 2-5 kg/ha for pure stands; it is sown in rows cm apart at a depth of cm. When grown as a rainfed crop in arid regions best results were obtained in India by planting equal amounts of early and late types in alternate rows. Moth bean is frequently sown towards the end of the rainy season and grown on residual soil moisture. Weed control is important until a full canopy has developed. Irrigation and fertilizer applications are rare. In India moth bean is grown as a sole crop or intercropped with pearl millet, sorghum or other cereals, occasionally with pulses. It is grown as a green manure in rotation with cotton. The most important diseases of moth bean are mung bean yellow mosaic virus (MYMV) transmitted by white fly (Bemisia tabaci), and root rot and seedling blight caused by Macrophomina phaseolina, which is soil- and seed-borne. Cultivars resistant to yellow mosaic are available; some cultivars are moderately resistant to Macrophomina phaseolina. Moth bean is also affected by nematodes, especially Meloidoigyne incognita. It is parasitized by several Striga species. Bruchids (Callosobruchus spp.) feed on the seed during storage. Plants are difficult to harvest with a mower because of the prostrate branches. They are usually cut with a sickle, left to dry for one week, then threshed and winnowed. Average seed yields of moth bean are only kg/ha, although in the United States and Australia experimental seed yields of up to 2600 kg/ha have been obtained. Yield of green matter for forage is t/ha and of hay t/ha. Genetic resources and breeding The largest germplasm collection of moth bean is at the National Bureau of Plant Genetic Resources (NBPGR), New Delhi, India, where more than 1000 accessions are held. Smaller collections are available in the United States (USDA Southern Regional Plant Introduction Station, Griffin, Georgia, 56 accessions), Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, Kikuyu, 47 accessions) and the Russian Federation (N.I. Vavilov All- Russian Scientific Research Institute of Plant Industry, St. Petersburg, 56 accessions). Increased efforts in germplasm collection, characterization, evaluation and preservation are recommended. Improved moth bean cultivars have been developed and released in India, e.g. 'RMO-40', 'RMO-225', 'RMO-257', 'RMO-435' and 'Jwala'. Genetic transformation of moth bean has been achieved using particle bombardment or Agrobacterium-mediated transfer. Prospects Moth bean is considered to be one of the most drought-tolerant pulse crops, but its spreading habit, which makes harvesting difficult, and the lack of information on its potential and on appropriate management practices limits its spread and use. Although recorded from various countries, it has not become important in tropical Africa. It could, however, increase production of food and forage in arid and semi-arid regions, and protect the soil against erosion. The ecological limits, optimal cultivation practices and most appropriate cultivars should be investigated. Priorities for breeding include the development of erect, early maturing types, resistance to diseases and high nutritional quality of the seed. Major references Kay, 1979; Narain, Singh & Kumar, 2000; Negi, Boora & Khetarpaul, 2001; Thulin, 1983; van Oers, 1989a. Other references Bogdan, 1977; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Kamble et al., 2003;

201 VlGNA 203 Kathju et al., 2003; Khatri, 2004; National Academy of Sciences, 1979; Nimkar, Mandwe & Dudhe, 2005; Rathore, 2001; Thulin, 1993; USDA, Sources of illustration van Oers, 1989a. Authors M. Brink & P.C.M. Jansen Based on PROSEA 1: Pulses. VlGNAADENANTHA (G.Mey.) Maréchal, Mascherpa & Stainier Protologue Taxon 27: 202 (1978). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 22 Synonyms Phaseolus adenanthus G.Mey. (1818). Vernacular names Wild bean (En). Pois marron (Fr). Fava caranguejo (Po). Origin and geographic distribution Vigna adenantha most probably originated from the Neotropics, where it has its greatest variability. It is distributed pantropically and is occasionally cultivated. In tropical Africa it occurs in most countries, but it has not been recorded from Ethiopia, Namibia, Botswana, Zambia, Zimbabwe or Mozambique. In the Indian Ocean islands it is found in Madagascar, the Seychelles and Réunion. Uses The green pods and ripe seeds of Vigna adenantha are eaten as emergency food. In Liberia the plant is or has been cultivated for its edible tuberous roots, which are cooked and eaten. The tuberous roots are also eaten in times of food scarcity in India. Cattle in Sudan browse the plant. In Nigeria a decoction of the whole plant is used as a medicine for gonorrhoea, and mixed with rice water to treat diabetes. With its large pink and white flowers which turn yellow with age, Vigna adenantha may be grown as an ornamental climber. Properties In tropical America Vigna adenantha provides a good forage containing 17.4% crude protein and 0.18% P. Botany Perennial climbing herb up to 4 m long, with tuberous roots; stem twining, glabrous or sparsely hairy, rooting at the lower nodes. Leaves alternate, 3-foliolate; stipules oblong-ovate, 3-6 mm long, base slightly cordate, apex acute, conspicuously veined; petiole 1-14 cm long, rachis cm long; petiolules 3-4 mm long, hairy; leaflets ovate to rhombic, lateral ones slightly asymmetric, (2.5-)5-10(- 14) cm x (1.5-) (-8) cm, base rounded or truncate, apex obtuse to acute, sparsely appressed-hairy on both sides, venation reticulate. Inflorescence an axillary false raceme 5-30 cm long, 6-12-flowered; peduncle up to 25 cm long, rachis 2-7 cm long. Flowers bisexual, papilionaceous; pedicel 2-3 mm long, with ovate-oblong bracteoles 3 4 mm x 2 mm; calyx with tube 3-4 mm long, the 3 lower lobes falcate or narrowly oblong, 3-5 mm long, the upper pair fused into a short, bifid lip, sparsely pubescent; corolla with almost circular standard, cm x cm, rose or white with green veins and a green basal eye surrounded by violet-purple inside, wings c. 3 cm long, white-tinged violet, green and yellow at the base, keel c. 5 cm long, with a long beak, spirally incurved for about 3 turns, white to violet-blue; stamens 10, 9 fused but upper one free; ovary superior, appressed-hairy, style slender, strongly curved. Fruit an oblong pod 7-15 cm x cm, slightly curved, flattened, glabrous or slightly hairy, 9-15-seeded. Seeds reniform, mm x mm x2.5 5 mm, dark reddish brown; hilum central, small, white. Vigna comprises about 80 species and occurs throughout the tropics. However, studies of the embryological characters indicate that Vigna adenantha is possibly better classified in the genus Phaseolus. The seed has a large cavity between the cotyledons which enables it to float, and the distribution pattern of the species indicates that seeds are sometimes dispersed by sea water. Ecology Vigna adenantha is found in humid or swampy locations, along the sea shore and rivers, and in cultivated and disturbed areas at low altitudes. Vigna adenantha is a short-day plant. Management For uniform and faster germination, seeds need scarification. Genetic resources and breeding The Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia holds 143 accessions of Vigna adenantha. In tropical Africa the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, holds 18 accessions. Vigna adenantha is widespread pantropically and is not in danger of genetic erosion. Prospects Vigna adenantha will remain of minor importance as an emergency food. More research is needed to evaluate its potential as food, forage, medicinal and ornamental crop. Major references Burkill, 1995; du Puy et al., 2002; Faigón Soverna, Galati & Hoc, 2003; Gillett et al., 1971; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors),

202 204 CEREALS AND PULSES Other references CSIR, 1969; Dalziel, 1937; Friedmann, 1994; Hepper, 1958; ILDIS, 2005; Lai & Pitman, 1987; Maréchal, Mascherpa & Stainier, 1978; Pitman & Singer, 1985; Tateishi, 1988; Thulin, Authors M. Brink & P.C.M. Jansen VIGNA ANGULARIS (Willd.) Ohwi & H.Ohashi Protologue Journ. Jap. Bot. 44(1): 29 (1969). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n - 22 Synonyms Phaseolus angularis (Willd.) W.Wight (1909). Vernacular names Adzuki bean, azuki bean (En). Haricot adzuki (Fr). Feijâo adzuki (Po). Origin and geographic distribution The exact origin of adzuki bean is not known; wild types occur in Nepal, south-eastern China, Taiwan, Korea and Japan. Cultivation is known since ancient times from northern Korea, China and Japan. Adzuki bean has been introduced to many countries in the world. In Africa experimental plantings have been carried out in DR Congo, Kenya and Angola, but up-to-date information is lacking. Adzuki bean has also been recorded for Madagascar and the Seychelles. Uses The dried seeds of adzuki bean are eaten, either cooked whole or made into flour for use in soups, cakes, confectionery and ice cream. Adzuki bean is particularly popular in China, Taiwan, Korea and Japan ('azuki an'), where the red seeds have a cultural value related to birth, wedding and death. Immature seeds and sprouted seeds are eaten as a vegetable. The seeds may be popped like maize grain, used as coffee substitute or eaten candied. Adzuki bean is also grown for forage, as green manure and for soil conservation. Flour is also used for shampoos, to make facial creams and as ingredient in culture media. In China the seeds are used to treat kidney problems, constipation, abscesses, certain tumours, threatened miscarriage, retained placenta, nonsecretion of milk and for improvement of blood circulation and urination. The leaves are said to lower fever and the sprouts are used to avert threatened abortion caused by injury. Production and international trade No statistics on the world production of adzuki bean are available. Major producers of the crop are China (670,000 ha), Japan (60,000 ha), South Korea (25,000 ha) and Taiwan (15,000 ha). Japan produces about 100,000 t/year and consumes about 140,000 t/year; it imports from China, Taiwan, the United States, Thailand and Canada. Average export from China in the 1990s was 25,000-40,000 t/year. Both the seed and the seed flour are important trade items in oriental markets. Properties Mature, raw adzuki bean seeds contain per 100 g edible portion: water 13.4 g, energy 1377 kj (329 kcal), protein 19.9 g, fat 0.5 g, carbohydrate 62.9 g, dietary fibre 12.7 g, Ca 66 mg, Mg 127 mg, P 381 mg, Fe 5.0 mg, Zn 5.0 mg, vitamin A 17 IU, thiamin 0.46 mg, riboflavin 0.22 mg, niacin 2.6 mg, vitamin B mg, folate 622 ig and ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 191 mg, lysine 1497 mg, methionine 210 mg, phenylalanine 1052 mg, threonine 674 mg, valine 1023 mg, leucine 1668 mg and isoleucine 791 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 113 mg and oleic acid 50 mg (USDA, 2005). Adzuki bean seeds have a sweet, nutty taste. Enzyme-resistant fractions of adzuki bean seeds have shown hypocholesterolaemic effects in rats. Hot water extracts have shown in-vivo hypoglycaemic and antitumour properties. Water extracts of the seed coat have shown hepatoprotective activity. Botany Annual, usually bushy and erect herb up to 90 cm tall, sometimes climbing or prostrate and rooting at the nodes; taproot40 50 cm long. Leaves alternate, 3-foliolate; stipules small, peltate, often bifid with basal appendages; stipels lanceolate; leaflets lanceolate to ovate, 5 10 cm x 5-8 cm, acuminate, entire to 3-lobed. Inflorescence an axillary false raceme, 2-20-flowered; peduncle long in lower nodes to very short in upper nodes. Flowers papilionaceous, bisexual; pedicel short, bearing an extrafloral nectary at base; bracteoles longer than calyx; calyx campanulate, with short teeth; corolla mm long, bright yellow, standard orbicular, wings oblong, keel turned towards the right, with a horn-shaped spur on the left side; stamens 10, 9 fused and 1 free; ovary superior, shortly hairy, style abruptly bent in upper part, hairy on one side near top, stigma lateral, discoid. Fruit a cylindrical pod 5-13 cm x 0.5 cm, pendulous, slightly constricted between the seeds, nearly glabrous, pale yellow, blackish or brown, 2-14-

203 VIGNA 205 Vigna angularis - 1, fruiting branch; 2, flower; 3, seed. Source: PROSEA seeded. Seeds cylindrical with rounded ends, flattened, mm x mm, smooth, wine red, occasionally buff, creamish, black or mottled. Seedling with hypogeal germination; primary leaves simple, opposite, cordate. Vigna comprises about 80 species and occurs throughout the tropics. Vigna angularis belongs to subgenus Ceratotropis, which also includes Vigna radiata (L.) R.Wilczek (mung bean), Vigna umbellata (Thunb.) Ohwi & H.Ohashi (rice bean), Vigna mungo (L.) Hepper (black gram) and Vigna aconitifolia (Jacq.) Maréchal (moth bean). Cultivated plants of Vigna angularis have been classified as var. angularis, wild plants as var. nipponensis (Ohwi) Ohwi & H.Ohashi. Wild adzuki bean has an indeterminate growth habit with thin twining stems, small leaves, short and strongly dehiscent black to grey pods and black-mottled seeds. Numerous cultivars have been recorded within Vigna angularis, differing in time to maturity, seed colour and plant habit. Intermediate types between wild and cultivated plants, called weedy types, have been found in Japan. The seeds of adzuki bean retain their viability for at least 5 years when stored with about 13% moisture content, at 15% relative humidity. Germination requires a soil temperature above 6-10 C, with C being optimal. Emergence takes 7-20 days. Growth is slow compared to other pulses. Flowering lasts days and can occur up to 3 times when planted early in the growing season. Selfpollination is predominant, but cross-pollination also occurs. The growth duration is (60-) (-190) days. Nitrogen fixation levels up to 100 kg N/ha have been observed, the amount depending on soil moisture content and ph. Adzuki bean effectively nodulates with Bradyrhizobium bacteria. Ecology Adzuki bean performs best in subtropical and warm temperate climates. It requires average temperatures of C for optimal growth. It tolerates high temperatures but is sensitive to frost. In the tropics it is more suitable for higher altitudes. Adzuki bean grows in areas with average annual rainfall of mm. It is a quantitative short-day plant but day-neutral cultivars exist. Adzuki bean can be grown on a wide range of soils (ph 5-7.5), provided they are well drained. Management Propagation of adzuki bean is by seed. The 1000-seed weight is g. Sowing practices differ greatly but usually seed is sown 2-3 cm deep, in rows cm apart and cm within the row; sometimes it is broadcast. Seed rates vary widely (8-70 kg/ha). Because of the relatively slow growth of adzuki bean, weed control is very important, particularly between germination and flowering. Fertilizer application differs widely. An adzuki bean crop yielding 2160 kg/ha was recorded to have an uptake per ha of 74 kg N, 18 kg P and 50 kg K. Irrigation of adzuki bean is not normally done. In China adzuki bean is often intercropped with maize, sorghum and millet. In Japan adzuki bean is grown in rotation with many crops (e.g. rice, wheat, sweet potato, yam). The seed may be sown directly in rice stubble at a high rate to reduce weed problems. Numerous fungi and bacteria are known to cause diseases in adzuki bean, including powdery mildew (Erysiphe polygoni, synonym: Erysiphe betae), brown stem rot (Cephalosporium gregatum, synonym: Phialophora gregata) and bacterial blight (Xanthomonas campestris). Several insect pests, such as the adzuki pod worm (Matsumuraeses phaseoli), the Japanese butterbur borer (Ostrinia scapulalis pacified) and cutworm (Spodoptera litura) attack the crop. Bean weevil (Callosobruchus chinensis)

204 206 CEREALS AND PULSES attacks the stored seed. In general the pods of adzuki bean do not shatter readily and the crop can be harvested with a mower or bean harvester. Traditionally, plants are cut by hand and allowed to cure on the ground for several days before being stacked into drying piles. Drying occurs until moisture content of the seed is about 16% and threshing can start. Some pods are very thin and in wet conditions seed may germinate in the pods. For hay, adzuki bean should be cut when the pods are about half mature. For seed, cutting is done when all pods are mature. Seed yields up to 3500 kg/ha are obtained. In an experimental planting in Kenya seed yields were kg/ha. Genetic resources and breeding Large germplasm collections of adzuki bean are held in China (Institute of Crop Germplasm Resources (CAAS), Beijing, more than 3700 accessions) and Japan (Tokachi Agricultural Experiment Station, Hokkaido-ken, about 2500 accessions). In China, Japan, Korea and Taiwan breeding has resulted in locally adapted better yielding cultivars, e.g. 'Baihong No 1' (China), 'Erimo' (Japan), 'Chungwonpat' (Korea) and 'Kaohsiung No 3' (Taiwan). In Japan alone more than 300 cultivars, landraces and breeding lines have been registered. In-vitro adzuki bean plants are routinely obtained using epicotyls as explants. A genetic transformation system for adzuki bean has been established using Agrobacterium-mediated transfer. A genetic linkage map has been constructed using molecular (RAPD, RFLP) and morphological markers. Prospects Adzuki bean is a suitable crop for the subtropics and the high-altitude tropics. The potential of adzuki bean as an anti-erosion crop should not be overlooked either. Further research on its potential in the high-altitude regions of tropical Africa is recommended. Major references Kay, 1979; Lumpkin & McClary, 1994; Schuster et al., 1998; van Oers, 1989b; Zong et al., Other references Duke, 1981; Han et al., 2003; Han et al., 2004; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Itoh et al., 2004; Itoh, Umekawa & Furuichi, 2005; Kaga et al., 1996a; USDA, 2005; Yamaguchi, 1992; Yamada et al., Sources of illustration van Oers, 1989b. Authors P.CM. Jansen Based on PROSEA 1: Pulses. VlGNAMUNGO (L.) Hepper Protologue Kew Bull. 11(1): 128 (1956). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number In = 22 Synonyms Phaseolus mungo L. (1767). Vernacular names Black gram, urd bean, urad bean (En). Haricot urd, urd (Fr). Feijào urida (Po). Mchooko mweusi (Sw). Origin and geographic distribution Black gram was most probably domesticated in India from its wild ancestral type, which is also found in Bangladesh, Pakistan and Myanmar. At present black gram cultivation is of major importance in India only, but it is also grown to some extent throughout tropical Asia. In Africa it is grown in Gabon, DR Congo, Kenya, Uganda, Tanzania, Malawi, Mozambique, South Africa, Madagascar and Mauritius. It is grown in the United States and Australia mainly as a fodder crop. Uses Black gram seeds are eaten as a pulse, direct or in various preparations (whole or split, boiled or roasted, ground into flour for cake, bread or porridge). It is with the flour of black gram that in India the flat biscuits 'papadum' are made. Seed sprouts are also consumed. Green pods are eaten as a cooked vegetable. Small quantities of the pods and foliage are used to supplement cattle feed or as forage. Sometimes black gram is sown as a cover crop and for green manure. The pod walls are fed to cattle. Flour from the seed is used as a substitute for soap; it makes the skin soft and smooth. In traditional medicine, the seed is used for its suppurative, cooling and astringent properties, e.g. pounded and applied as a poultice on abscesses. Production and international trade In India, the major producer and consumer, average annual production of black gram seed is about 1.3 million t from 3 million ha. Thailand produces annually about 90,000 t which is mainly exported to Japan, where seed sprouts from black gram are preferred to those from green gram (Vigna radiata (L.) R.Wilczek) because of their longer shelf life. Annual production in Pakistan is about 28,000 t from 57,000 ha, and in Sri Lanka 6000 t from 8000 ha. Sri Lanka additionally imports 6000 t/year. Properties Black gram seeds contain per 100 g edible portion: water 8.6 g, energy 1470 kj (351 kcal), protein 25.1 g, fat 1.8 g, carbohydrate 61.0 g, crude fibre 4.4 g, Ca 196 mg, Mg 260 mg, P 575 mg, Fe 6.8 mg, Zn 3.1 mg, vita-

205 VlGNA 207 min A 114 IU, thiamin 0.36 mg, riboflavin 0.28 mg, niacin 1.8 mg, vitamin Ik 0.28 mg, folate 628 Xg and ascorbic acid 4.8 mg. The essential amino-acid composition of black gram seeds per g nitrogen is: tryptophan 65 mg, lysine 415 mg, methionine 91 mg, phenylalanine 365 mg, threonine 217 mg, valine 351 mg, leucine 518 mg and isoleucine 319 mg (Haytowitz & Matthews, 1986). Black gram seeds have shown anti-atherogenic activity in guinea pigs. Botany Erect, hairy annual herb up to 100 cm tall, sometimes twining, with a welldeveloped taproot; stem diffusely branched from the base, furrowed. Leaves alternate, 3- foliolate; stipules peltate, ovate; petiole 6-20 cm long; stipels falcate; leaflets ovate or rhombic-ovate, 4 10 cm x 2-7 cm, entire, acuminate. Inflorescence an axillary false raceme; peduncle up to 18 cm long. Flowers bisexual, papilionaceous, small; bracteoles linear to lanceolate, exceeding the calyx; calyx campanulate; corolla yellow, standard mm wide, wings about as long as standard, keel spirally coiled with a terminal horn-like appendage; stamens 10, 9 united and 1 free; ovary superior, style spirally curved. Fruit a cylindrical pod 4-7 cm x 0.5 cm, erect or almost so, with long hairs and short hooked beak, 4-10-seeded. Seed el- Vigna mungo - 1, part of fruiting branch; 2, flower; 3, seed. Source: PROSEA lipsoid, up to 5 mm long, with square ends, and raised and concave hilum, usually black or mottled, sometimes green. Seedling with epigeal germination. Vigna comprises about 80 species and occurs throughout the tropics. Vigna mungo belongs to subgenus Ceratotropis, which also includes Vigna radiata (L.) R.Wilczek (mung bean), Vigna umbellata (Thunb.) Ohwi & H.Ohashi (rice bean), Vigna angularis (Willd.) Ohwi & H.Ohashi (adzuki bean) and Vigna aconitifolia (Jacq.) Maréchal (moth bean). There has been confusion on the taxonomie status of Vigna mungo and Vigna radiata; because they are closely related it was proposed that they be grouped into a single species. However, at present they are considered as 2 separate species with as major differences: flower colour (bright yellow in Vigna mungo, pale yellow in Vigna radiata), pocket on the keel (longer in Vigna mungo than in Vigna radiata), fruit shape (pods of Vigna mungo are shorter and erect on the peduncle, in Vigna radiata the pods are longer and spreading or pendulous). Three taxa are distinguished within Vigna mungo: - var. mungo, with large, black-seeded and early-maturing cultivars; - var. viridis Bose, with greenish dull or glossy seeds and late-maturing cultivars; - var. silvestris Lukoki, Maréchal & Otoul, the wild type; compared to cultivated types it is smaller, more climbing, more hairy, with denser inflorescences and small seeds with prominent raised aril; it is considered the ancestor of the cultivated black gram. For cultivated types a classification into cultivars and cultivar groups would be more appropriate. Germination of black gram normally takes 7 10 days. Flowering starts days after sowing. Flowers are normally self-pollinating, with the pollen shedding before the flower opens. Maturity is reached in days after sowing. Black gram effectively nodulates with Bradyrhizobium bacteria. Ecology Black gram is basically a warm season crop, but in India it is grown in both summer and winter, up to 1800 m altitude. It is quite drought resistant but intolerant of frost and prolonged cloudiness. It is normally grown in areas with an average temperature of C and an annual rainfall of mm. In higher rainfall areas it may be grown in the dry season on residual moisture. Heavier, well-drained soils such as black-cotton soils

206 208 CEREALS AND PULSES with ph 6-7 are preferred, but black gram is also grown on lighter soils. Management Black gram is propagated by seed. The 1000-seed weight is g. It is sown broadcast or in rows at a depth of cm. The seed rate is kg/ha, space between rows cm, space within the row cm. Thorough field preparation is not required; rough tillage suffices. Weeding is done only once or twice until the canopy is established. The crop is mainly rainfed and fertilizer application is not common. In the wet season in India it is mainly intercropped, with sugar cane, cotton, groundnut, sorghum or pigeon pea as the main crops. In the dry season it is often sole cropped on rice fallow. Important diseases of black gram are mung bean yellow mosaic virus (MYMV), Cercospora leaf spot (caused by Cercospora sp.), web blight {Rhizoctonia solani, synonym: Thanatephorus cucumeris) and powdery mildew (Erysiphe polygoni, synonym: Erysiphe betae). The most serious pests are white fly and thrips. In storage the seeds are attacked by bruchids (Callosobruchus spp.). Black gram must be harvested before the pods are fully ripe to prevent shattering. The plants are cut or uprooted, stacked to dry for up to 7 days, and threshed by beating with sticks or animal trampling. Alternatively, the pods may be handpicked. Yield of dry seed averages kg/ha but it can reach kg/ha. In India black gram seeds are usually processed into split seeds (dhal). Genetic resources and breeding About 2100 accessions of black gram are maintained by the National Bureau of Plant Genetic Resources (NBPGR), New Delhi, India, at its various research stations. The USDA Southern Regional Plant Introduction Station, Griffin, Georgia, United States, holds 300 accessions, and the Asian Vegetable Research and Development Centre (AVRDC) in Taiwan maintains a collection of 200 accessions. Breeding programmes for improvement of this pulse aim for a plant type combining determinate growth habit with a plant height of 30 cm, early maturity (60-90 days), and suitability for many different agroclimatic regions. Sources of resistance against most current diseases are available and several resistant cultivars have been released. Genetic variability of black gram is great, allowing development of suitable cultivars for most tropical and subtropical climates. Genetic transformation of black gram has been achieved using Agrobacterium-mediated transfer. Prospects It would be worthwhile trying black gram on a much larger scale in tropical Africa because of its highly nutritious seeds and its wide ecological applicability. Germplasm diversity needs to be exploited to obtain suitable cultivars for Africa. Major references Arora & Shri S. Mauria, 1989; Dikshit et al., 2004; Kay, 1979; Lawn & Ahn, 1985; Souframanien & Gopalakrishna, Other references CSIR, 1976; Ghafoor et al., 2001; Gillett et al, 1971; Haytowitz & Matthews, 1986; ILDIS, 2005; Maréchal, Mascherpa & Stainier, 1978; Midya et al, 2005; Purseglove, 1968; Saini & Jaiwal, 2005; Srivastava & Joshi, Sources of illustration Arora & Shri S. Mauria, Authors P.C.M. Jansen Based on PROSEA 1: Pulses. VlGNARADIATA (L.) R.Wilczek Protologue Fl. Congo Beige 6: 386 (1954). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number In = 22 Synonyms Phaseolus radiatus L. (1753), Phaseolus aureus Roxb. (1832). Vernacular names Mung bean, green gram, golden gram (En). Haricot mungo, mungo, ambérique, haricot doré (Fr). Feijâo mungo verde (Po). Mchooko, mchoroko (Sw). Origin and geographic distribution Mung bean originated in India or the Indo-Burmese region where it has been cultivated for millen- Vigna radiata -planted

207 VlGNA 209 nia. The ancient cultivation of mung bean in India is supported by fossilized remains discovered in central India and dated BC. Mung bean cultivation spread in early times to most other Asian countries and later to Africa, Australia, the Americas and the West Indies. It has not become a major crop outside Asia, although mung bean is cultivated in many tropical African countries. In certain areas of Kenya, especially the Eastern Province, mung bean is the principal cash crop. Uses Mature mung bean seeds or flour enter a variety of dishes such as soups, porridge, snacks, bread, noodles and even ice-cream. In Kenya mung bean is most commonly consumed as whole seeds boiled with cereals such as maize or sorghum. Boiled whole seeds are also fried with meat or vegetables and eaten as a relish with thick maize porridge ('ugali') and pancakes ('chapatti'), whereas consumption of split seeds (dhal) is common among people of Asian descent. In Ethiopia the seeds are used in sauces. In Malawi the seeds are cooked as a side dish, mostly after removing the seed coat by grinding. In India and Pakistan the dried seeds are consumed whole or after splitting into dhal. Split seeds are eaten fried and salted as a snack. The seeds may also be parched and ground into flour after removing the seed coat; the flour is used in various Indian and Chinese dishes. The flour may be further processed into highly valued starch noodles, bread, biscuits, vegetable cheese and extract for the soap industry. Sprouted mung bean seeds are eaten raw or cooked as a vegetable; in French they are erroneously called 'germes de soja', in English 'bean sprouts'. Immature pods and young leaves are eaten as a vegetable. Plant residues and cracked or weathered seeds are fed to livestock. Mung bean is sometimes grown for fodder, green manure or as a cover crop. The seeds are said to be a traditional source of cures for paralysis, rheumatism, coughs, fevers and liver ailments. Production and international trade Reliable production statistics for mung bean are difficult to obtain, as its production is often lumped together with that of other Vigna and Phaseolus spp. India is the main producer, with an estimated production in the late 1990s of about 1.1 million t. China produced 891,000 t (19% of total pulse production in China) from 772,000 ha in No mung bean production statistics are available for Africa. China exported 110,000 t in 1998, 290,000 t in 1999 and 88,000 t in All mung bean produced in India is for domestic consumption. In most parts of Africa where there are Asian communities, mung bean food products are sold in the cities. Properties The composition of mature mung bean seeds per 100 g edible portion is: water 9.1 g, energy 1453 kj (347 kcal), protein 23.9 g, fat 1.2 g, carbohydrate 62.6 g, dietary fibre 16.3 g, Ca 132 mg, Mg 189 mg, P 367 mg, Fe 6.7 mg, Zn 2.7 mg, vitamin A 114 IU, thiamin 0.62 mg, riboflavin 0.23 mg, niacin 2.3 mg, vitamin B mg, folate 625 (ig and ascorbic acid 4.8 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 260 mg, lysine 1664 mg, methionine 286 mg, phenylalanine 1443 mg, threonine 782 mg, valine 1237 mg, leucine 1847 mg and isoleucine 1008 mg (USDA, 2004). The starch consists of 28.8% amylose and 71.2% amylopectin. Mung bean seed is highly digestible and low in antinutritional factors. It causes less flatulence than the seed of most other pulses, making it suitable for children and older people. Mung bean starch is considered to have a low glycaemic index, i.e. to raise the blood sugar level slowly and steadily. The composition of sprouted mung bean seeds per 100 g edible portion is: water 90.4 g, energy 126 kj (30 kcal), protein 3.0 g, fat 0.2 g, carbohydrate 5.9 g, dietary fibre 1.8 g, Ca 13 mg, Mg 21 mg, P 54 mg, Fe 0.9 mg, Zn 0.4 mg, vitamin A 21 IU, thiamin 0.08 mg, riboflavin 0.12 mg, niacin 0.75 mg, vitamin B mg, folate 61 ug and ascorbic acid 13.2 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 37 mg, lysine 166 mg, methionine 34 mg, phenylalanine 117 mg, threonine 78 mg, valine 130 mg, leucine 175 mg and isoleucine 132 mg (USDA, 2004). Sprouting especially leads to an increased ascorbic acid concentration. Mung bean hay contains: moisture 9.7%, crude protein 9.8%, fat 2.2%, crude fibre 24.0%, ash 7.7%, N-free extract 46.6%, digestible crude protein 7.4%, total digestible nutrients 49.3%. Aqueous extracts of mung bean seed have shown in-vivo hypotensive and hepatoprotective effects in rats. Extracts from mung bean seeds and husks have shown antioxidative effects. Description Annual, erect to semi-erect, slightly pubescent herb up to 1.3 m tall; root system consisting of a well-developed taproot with deeply placed lateral roots; stem much branched, with a tendency to twine at the tips, angular, covered with long spreading hairs.

208 210 CEREALS AND PULSES Vigna radiata - 1, part of flowering branch; 2, part of fruiting branch; 3, seeds. Source: PROSEA Leaves alternate, 3-foliolate (sometimes 5- foliolate), dark green; stipules 5-18 mm x 3-10 mm, peltate, ovate, rhomboid or obovateoblong; petiole 5-21 cm long, rachis cm long; stipels conspicuous, 5-10 mm long; petiolules 3-6 mm long; leaflets entire or 2 3-lobed, 5-18 cm x 3-15 cm, elliptical, rhomboid or ovate, base broadly cuneate or rounded, apex acuminate, glabrous or hairy on both surfaces, distinctly 3-veined from the base, the lateral leaflets unequal-sided. Inflorescence an axillary false raceme up to 20 cm long, 4 15( 30)- flowered. Flowers bisexual, papilionaceous; pedicel 2-3 mm long; calyx campanulate, tube 3-4 mm long and glabrous, lobes narrowly triangular, mm long, ciliate, upper pair united into a bifid lobe; corolla yellow or greenish, standard 11 mm x 16 mm, glabrous, wings c. 11 mm x 7 mm, keel c. 10 mm long, often tinged grey or reddish, with a long beak incurved almost 360, and with a distinct pocket on one side; stamens 10, 9 united and 1 free; ovary superior, sessile, c. 7 mm long, hairy. Fruit a linear-cylindrical pod (2.5 )4-9(-15) cm x 4-9 mm, usually straight, black or tawny brown, with brown short spreading pubescence, (7-)10 15( 20)-seeded, somewhat constricted between the seeds. Seeds mm x mm x mm, globose to ellipsoid or cubelike, commonly green but sometimes yellow, olive, brown, purplish brown or black, marbled or mottled with black patches, glossy or dull; hilum white, conspicuously flat, c. 1.5 mm x 0.5 mm; seed coat often with ridges, making the seed rough to the touch. Seedling with epigeal germination. Other botanical information Vigna comprises about 80 species and occurs throughout the tropics. Vigna radiata belongs to the subgenus Ceratotropis, a relatively homogenous and morphologically and taxonomically distinct group, primarily of Asian distribution. Other cultivated Asiatic Vigna species in this subgenus include Vigna aconitifolia (Jacq.) Maréchal (moth bean), Vigna angularis (Willd.) Ohwi & Ohashi (adzuki bean), Vigna mungo (L.) Hepper (black gram or urd bean), Vigna trilobata (L.) Verde, (pillipesara) and Vigna umbellata (Thunb.) Ohwi & Ohashi (rice bean). Hybrids have been obtained between many of these species. The species have often been confounded, especially Vigna radiata and Vigna mungo. The wild types of mung bean, which are usually smaller in all parts than cultivated types, are usually classified into 2 botanical varieties: - var. sublobata (Roxb.) Verde, occurring in India, Sri Lanka, South-East Asia, northern Australia (Queensland), in tropical Africa from Ghana to East Africa, southern Africa and Madagascar; var. setulosa (Dalzell) Ohwi & Ohashi, with large, almost orbicular stipules and dense long hairs on the stem, and occurring in India, China, Japan and Indonesia. The cultivated types of mung bean are grouped as Vigna radiata var. radiata, although a classification into cultivar groups would be more appropriate. Two types of mung bean cultivars are usually distinguished, based mainly on seed colour: golden gram, with yellow seeds, low seed yield and pods shattering at maturity; often grown for forage or green manure; - green gram, with bright green seeds, more prolific, ripening more uniformly, less tendency for pods to shatter. Two additional types are recognized in India, one with black seeds and one with brown seeds. Growth and development The minimum temperature for seed germination of mung bean is about 12 C, the optimum temperature

209 VlGNA 211 around 25 C. Seedlings emerge in 3-7 days. Mung bean is a short-duration crop, flowering within days and maturing within days after sowing. Self-pollination is the rule, but up to 5% outcrossing may occur. Flowers are usually pollinated during the night, before they open early in the morning. It takes 3-4 weeks from flower opening to mature pod. Flower abscission is prevalent and may reach 90%. Mung bean mostly has a determinate growth habit, but because the inflorescences remain meristematic and may redevelop flowers after a period of adverse conditions, it flowers and fruits over a period of several weeks. Green leaves, open flowers, green pods and ripe pods occur simultaneously on the same plant. A large part of the dry matter accumulated during seed filling may still be partitioned to vegetative parts and thus rapid senescence does not occur. Mung bean nodulates readily with Bradyrhizobium strains from the cowpea cross-inoculation group. Because those strains are rather common, mung bean shows little response to inoculation. Ecology Mung bean is a warm-season crop and grows mainly within a mean temperature range of C, the optimum being C. It can therefore be grown in summer and autumn in warm temperate and subtropical regions and at altitudes below 2000 m in the tropics. It is sensitive to frost. Mung bean is mostly grown in regions with an average annual rainfall of mm, but it can do with less. It withstands drought well, by curtailing the period of flowering and maturation, but it is susceptible to waterlogging. High humidity at maturity causes damage to seeds leading to seed discoloration or sprouting while still in the field. Mung bean cultivars differ markedly in photoperiod sensitivity, but most genotypes show quantitative short-day responses, flower initiation being delayed by photoperiods longer than hours. Mung bean grows in a wide range of soil types, but prefers well-drained loams or sandy loams with ph (5-)5.5-7(-8). Some cultivars are tolerant to moderate alkaline and saline soils. Propagation and planting Mung bean is propagated by seed. The 1000-seed weight is g. There is no seed dormancy, but germination can be affected by a hard seedcoat. Mung bean is broadcast or dibbled in hills or in rows. Recommended sowing rates are 5 30 kg/ha for sole cropped mung bean, and 3-4 kg/ha under intercropping. Recommended spacings are cm x 5-30 cm. For the more modern cultivars ripening in days, maximum yields are obtained at plant densities of 300, ,000 plants/ha. The latermaturing traditional cultivars generally need wider spacing. Recommended spacings for solecropped mung bean in Kenya are 45 cm between rows and 15 cm within the row, with a seed rate of 6-10 kg/ha and a sowing depth of 4-5 cm. Mung bean can be grown mixed with other crops such as sugar cane, maize, sorghum or tree crops in agroforestry systems. Shortduration mung bean is often relay-cropped to make use of a short cropping period. In Kenya mung bean is usually intercropped with maize, sorghum or millet; it is occasionally grown in pure stands or intercropped with other pulses. The usual practice here is to place 1-2 rows of mung bean between rows of a cereal, or to plant mung bean in the cereal row. Management In pure stands, 1 2 weedings are necessary during the early stages of growth. In Kenya weeding is done using hoes and machetes. Farmers do not normally apply any inorganic fertilizer to a mung bean crop. Mung bean uses residues from fertilizer applications to the main crops in the system, though it responds well to phosphorus. Nutrient removal per t of seed harvested (dry weight) is kg N, 3-5 kg P, kg K, kg Ca, kg S and kg Mg. The nutrient removal is much higher when crop residues are removed to be used for fodder. In its major area of cultivation, the monsoon tropics, mung bean is mainly grown as a rainy season crop on dryland or as a dry-season crop after the monsoon in rice-based systems on wetland, making use of residual moisture or supplementary irrigation. In some areas where adequate early rains occur, an early-season crop can be grown before the monsoon. In semiarid regions of Kenya with mm rainfall evenly distributed over 2 rainy seasons, 2 mung bean crops are grown per year. In the Wei Wei Integrated Development Project in Sigor, Kenya, mung bean is grown under irrigation. In India mung bean is often sown as a fallow crop on rice land as a green manure. Diseases and pests The most important and widespread fungal diseases of mung bean are Cercospora leaf spot (Cercospora canescens) and powdery mildew (Erysiphe polygoni). Less serious are scab {Elsinoë iwatae), anthracnose (Colletotrichum lindemuthianum) and rust (Uromyces spp.). Important bacterial diseases are blights caused by Xanthomonas and Pseu-

210 212 CEREALS AND PULSES domonas spp. Mung bean suffers from several virus diseases but they are not well described, except for mung bean yellow mosaic virus (MYMV), which is widespread in South Asia. The main insect pests are aphids (Aphis fabae, Aphis craccivora), bean fly (Ophiomyia phaseoli), thrips (Megalurothrips sjostedii), pod borers (Heliothis spp., Etiella zinckenella, Maruca testulalis) and pod-suckers such as the green stink bug (Nezara uiridula). In the drier areas of Kenya the apion weevil (Apion soleatum) may cause heavy losses. Stored mung bean seed is attacked by bruchids (Callosobruchus spp.). In Africa it is common to use ash made from neem (Azadirachta indica A.Juss.) leaves or cow dung to protect seeds against storage pests. Insecticides are seldom used on mung bean in tropical Africa. Harvesting When grown for the mature seed, mung bean is usually harvested when the pods begin to darken. Harvesting is highly labour intensive as the pods of most local cultivars of mung bean are highly susceptible to shattering and mature at different times. Mung bean is generally harvested in 2-5 handpickings at weekly intervals. In Kenya individual pods are picked as they mature. Where the crop matures uniformly, the entire plant is harvested and sun-dried before threshing. Short-duration cultivars, which ripen more uniformly, may be processed as whole plants with small rice threshers. Cultivars differ markedly in harvesting efficiency, depending on position (above or within canopy) and size of pods. Yield Average mung bean yields are low: kg/ha. Under irrigation in Kenya yields are obtained of 1.25 t/ha. Yields over 3 t/ha have been obtained in trials. Handling after harvest Handpicked pods are dried in the sun. Shattering can be speeded up by beating with a stick or by trampling. Seed is cleaned by screening and winnowing, and dried to a moisture content of 10-12% before storage. Properly dried mung bean seeds maintain high viability over a long period. Seed stored by small farmers for sowing is often of poor quality because of bruchid damage. To prepare mung bean sprouts, the seeds are soaked overnight, drained, placed in containers in the dark, sprinkled with warm water every few hours, and kept for 4-5 days at a temperature of 24 C and a relative air humidity of 60-70%. One kg of mung bean seed produces 6-10 kg sprouts. Genetic resources Large germplasm collections of mung bean are held in the Philippines (National Plant Genetic Resources Laboratory, University of the Philippines Los Banos (UPLB), Los Banos, about 6900 accessions), Taiwan (Asian Vegetable Research and Development Centre (AVRDC), Shanhua, about 5600 accessions), United States (Southern Regional Plant Introduction Station, Griffin, Georgia, about 3900 accessions), India (National Bureau of Plant Genetic Resources, New Delhi, about 3000 accessions) and China (CAAS, Beijing, about 3000 accessions). In tropical Africa germplasm collections of mung bean are held in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu, 330 accessions), Nigeria (International Institute of Tropical Agriculture, Ibadan, 125 accessions) and Ethiopia (International Livestock Research Institute, Addis Ababa, 40 accessions). Breeding In many traditional mung bean growing regions farmers still grow old landraces. Many cultivars have been developed from those landraces by pure-line selection. The traditional late robust types may be replaced by new types useful for short seasons and multiple cropping systems with mung bean occupying the land for short periods between major crops. These new types are short plants with high harvest index, reduced photoperiodic sensitivity and a relatively uniform maturity. Many modern cultivars with improved resistance to major diseases and pests have been released in the major producing countries. Sources of resistance have been identified in germplasm of mung bean and related species. Among the Asiatic Vigna species, black gram (Vigna mungo) shows most promise for interspecific hybridization with mung bean. AVRDC in Taiwan is working on the development of mung bean tolerant to diseases (leaf spot, powdery mildew) and pests (bean fly, bruchids). Information on mung bean breeding in Africa is scanty. In Kenya mung bean improvement work has been carried out by the National Dryland Farming Research Station, Machakos since the late 1970s. Germplasm was collected locally and was introduced from elsewhere, mainly from India and AVRDC. Promising lines were selected and 2 cultivars ('KVR22' and 'KVR26') have been released. 'KVR22' has a determinate growth habit and golden-yellow seed colour; it flowers in days and matures uniformly in days after germination. It has shown high resistance to MYMV, moderate resistance to powdery mildew and

211 VlGNA 213 tolerance to aphids, but it is susceptible to thrips and apion weevil. 'KVR26' has a determinate growth habit and a green seed colour; it flowers in days, and matures fairly uniformly in days. It is much appreciated for its high yield, earliness and large seed size. Direct in-vitro plant regeneration in mung bean is possible using cultured shoot tips, cotyledons and cotyledonary node expiants. Regeneration through organogenesis from callus has also been reported. Somatic embryogenesis has been induced from mature cotyledons, hypocotyl, nodal segments and leaf expiants. AVRDC uses molecular markers to select for resistance to diseases and pests and has worked on gene mapping using RFLP and isozyme electrophoresis. Agrobacterium-mediated genetic transformation of mung bean has been achieved. Prospects Mung bean is a suitable crop for tropical Africa, especially the semi-arid regions, because of its short crop cycle and nutritional quality. Furthermore, it has a niche on the international market for the production of bean sprouts. However, it has not yet become important in tropical Africa, which may be due to its low yields, susceptibility to diseases and pests, high labour requirement (weeding, harvesting), lack of suitable cultivars and good quality planting material, and lack of information on its potential benefits. It therefore deserves increased attention from research and extension. Major references Dana & Karmakar, 1990; Kay, 1979; Lawn, 1995; Lawn & Ahn, 1985; Mayeux, 1990; Ministry of Agriculture and Rural Development, 2002; Muthoka & Shakoor, 1988; Poehlman, 1991; Siemonsma & Arwooth Na Lampang, 1989; Westphal, Other references Avenido, Motoda & Hattori, 2001; Burkill, 1995; Chiu & Fung, 1997; Devi et al., 2004; Dookun, 2001; Duke, 1981; du Puy et al., 2002; Gillett et al., 1971; Hafeez, Asad & Malik, 1991; Hanelt & Institute of Plant Genetics and Crop Plant Research (Editors), 2001; Huijie et al., 2003; ILDIS, 2005; Jaiwal et al., 2001; Joshi & Saxena, 2002; Madar & Stark, 2002; Mugova & Mavunga, 2000; Thulin, 1989a; Tindall, 1983; USDA, 2004; Wu et al., Sources of illustration Siemonsma & Arwooth Na Lampang, Authors K.K. Mogotsi Based on PROSEA 1: Pulses. VlGNASUBTERRANEA (L.) Verde. Protologue Kew Bull. 35(3): 474 (1980). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number In = 22 Synonyms Glycine subterranea L. (1763), Voandzeia subterranea (L.) DC. (1825). Vernacular names Bambara groundnut, bambarra groundnut, earth pea, jugo bean (En). Voandzou, pois de terre, pois bambara (Fr). Mancara de Bijagó, jinguba de Cabambe (Po). Njugu mawe (Sw). Origin and geographic distribution The centre of origin of bambara groundnut is probably north-eastern Nigeria and northern Cameroon. It is found in the wild from central Nigeria eastwards to southern Sudan, and is now cultivated throughout tropical Africa, and to a lesser extent in tropical parts of the Americas, Asia and Australia. Its use as a pulse in West Africa was recorded by Arabic travellers in the 14 th Century. Its importance declined after the introduction of groundnut from the New World tropics. Uses Bambara groundnut is grown primarily for its seeds, which are used in many types of foods, some of which are an important part of the diet and play a role in traditional ceremonies (e.g. funeral rites) and gift exchanges. Mature, dry seeds are boiled and eaten as a pulse. Dried seeds, either whole or split, are also mixed with maize or plantains and then boiled. The seeds may be ground into flour, sometimes after roasting, to prepare a porridge. They are also added to maize flour to enrich traditional preparations. Sometimes seeds are soaked in water and ground into a Vigna subterranea -planted

212 214 CEREALS AND PULSES paste which is used to prepare fried or steamed dishes. Immature seeds are often boiled with salt and eaten as a snack. They are eaten during the 'hungry gap' during the growing season, when stores are empty and crops are not yet ready for harvest. Vegetable milk and fermented products similar to tempeh (from Glycine max L.) and dawadawa (Parkia biglobosa (Jacq.) R.Br, ex G.Don) can be made from the seeds. The seeds are fed to pigs and poultry, and the leafy shoots are used as fodder. In Senegal leaf preparations are applied to abscesses and infected wounds, leaf sap is applied to the eyes to treat epilepsy, and the roots are sometimes taken as an aphrodisiac. Pounded seeds mixed with water are administered to treat cataracts. The Igbo in Nigeria use the plant to treat venereal diseases. Production and international trade Reliable production figures for bambara groundnut are difficult to obtain, because the crop is mainly grown for home consumption and sale at local markets. In the early 1980s the estimated annual world production was 330,000 t, 45-50% of which was produced in West Africa. The major producers are Burkina Faso, Chad, Côte d'ivoire, Ghana, Mali, Niger and Nigeria, but the crop is also widely grown in eastern and southern Africa and in Madagascar. The main exporting countries are Burkina Faso, Chad, Mali, Niger and Senegal; they supply markets in Benin, Ghana, Nigeria and Togo. Properties Raw immature bambara groundnut seeds contain per 100 g edible portion: water 57.3 g, energy 636 kj (152 kcal), protein 7.8 g, fat 3.1 g, carbohydrate 30.0 g, fibre 3.0 g, ash 1.8 g, Ca 14 mg, P 258 mg and Fe 1.2 mg. The composition of mature dry seeds per 100 g edible portion is: water 10.3 g, energy 1537 kj (367 kcal), protein 18.8 g, fat 6.2 g, carbohydrate 61.3 g, fibre 4.8 g, ash 3.4 g, Ca 62 mg, P 276 mg, Fe 12.2 mg, ß-carotene 10 lg, thiamin 0.47 mg, riboflavin 0.14 mg, niacin 1.8 mg and ascorbic acid traces (Leung, Busson & Jardin, 1968). The content of essential amino acids per 100 g food is: tryptophan 192 mg, lysine 1141 mg, methionine 312 mg, phenylalanine 991 mg, threonine 617 mg, valine 937 mg, leucine 1385 mg and isoleucine 776 mg (FAO, 1970). As in other pulses, the sulphur-containing amino acids cystine and methionine are limiting. The main fatty acids in the seed oil are palmitic acid 18-24%, stearic acid 5-12%, oleic acid 18-24%, linoleic acid 34-40%, linolenic acid 2-3% and behenic acid 3-7%. A content of 21% linolenic acid and no oleic acid, however, has also been recorded. The ratio of saturated to unsaturated fatty acids is approximately 1:2. The oil content is too low for the seed to be used as a source of oil. Trypsin inhibition occurs. The seeds contain tannins, mainly in the seed coat. In comparative studies in Botswana and Ghana, tannin levels were found to be lowest in cream-coloured seeds, intermediate in red seeds and highest in black seeds. Cooking and other forms of processing (e.g. soaking, milling, hulling, germination, fermentation) reduce the concentration of antinutritional factors. Ripe seeds are very hard and usually have to be cooked longer than those of other legumes. Cream-coloured seeds are often preferred to red and black seeds, because they are less bitter ('sweeter') and take less time to cook. Large seeds are preferred over smaller ones, e.g. for use as snack; smaller seeds are ground into flour for use in various recipes. Dried leaves for fodder contain crude protein 15.9%, crude fibre 31.7%, ash 7.5% and fat 1.8%. Description Annual herb with creeping stems branching just above ground level; root- Vigna subterranea - 1, habit of flowering plant; 2, flower; 3, fruits; 4, seed. Source: PROSEA

213 VIGNA 215 system consisting of a tap root with lateral roots lower down, with rounded and sometimes lobed nodules. Leaves alternate, 3-foliolate, glabrous; stipules c. 3 mm long, spurred, striate; petiole erect, grooved, up to 30 cm long, thickened at base, rachis (0.1-)1 2.5 cm long; stipels ovate-oblong, up to 3 mm long; petiolules 1-3 mm long; leaflets elliptical to oblanceolate, 3-10 cm x 1-5 cm. Inflorescence an axillary false raceme, close to the ground, (l-)2(-3)-flowered; peduncle cm long. Flowers bisexual, papilionaceous, shortly pedicelled; calyx with tube c. 1 mm long and 5 lobes c. 1 mm long; corolla whitish-yellow, standard obovate, 4-7 mm long, wings and keel slightly shorter; stamens 10, 9 with filaments fused for more than half their length and 1 free; ovary superior, 1-celled, style bent. Fruit an almost globose indéhiscent pod c. 2.5 cm in diameter, usually 1-seeded. Seed mm x mm x mm, variously coloured from white to cream, red, black or brown, sometimes mottled, blotched or striped; eye around the hilum sometimes present, colour and shape variable. Seedling with hypogeal germination. Other botanical information Vigna comprises about 80 species and occurs throughout the tropics. However, it is likely that the American species will be placed in a separate genus in the near future. There are considerable morphological difference between wild and domesticated types of bambara groundnut. Wild bambara groundnut produces long runners, the pods are thin and do not wrinkle upon drying, and the seeds are small (9 11 mm long) and uniform in size. Domesticated types are more compact, with longer, less slender and more erect petioles, fleshy pods which wrinkle on drying, and larger seeds (11-15 mm long). Morphological and isozyme data indicate a gradation from wild to domesticated bambara groundnut through weedy populations. Wild and domesticated types are sometimes distinguished as var. spontanea (Harms) Hepper (wild) and var. subterranea (cultivated). No cultivars of bambara groundnut have been named, but genotypes are distinguished on the basis of seed attributes (colour, size, hardness) and plant form (bushy or spreading). Sometimes names are based on the location where the seed was collected. Growth and development The optimum temperature for germination of bambara groundnut is C; below 15 C and above 40 C, germination is very poor. Emergence takes 5-21 days. Vegetative development may continue after reproductive development has started. Flowering starts days after sowing and may continue until the plant dies. Selfpollination is the rule. After fertilization, the peduncle grows and pods form on or below the ground. Pods reach their maximum size in about 30 days. The seeds expand and reach maturity during the following 10 days, when the parenchymatous layer surrounding the embryo has disappeared and brown patches appear on the outside of the pod. Seeds are mature 3-6 months after germination. Bambara groundnut is able to fix atmospheric nitrogen by nodulating with bacteria of the Bradyrhizobium group. Ecology Bambara groundnut is cultivated in the tropics at altitudes up to 2000 m. A frostfree period of at least 3 months is necessary. Average day temperatures of C and full sun are preferred. The crop tolerates drought and is cultivated successfully in areas with an average annual rainfall of mm, though optimum yields are obtained when rainfall is higher ( mm/year). It is also grown in humid conditions, e.g. in northern Sierra Leone, where the annual rainfall exceeds 2000 mm. There are considerable differences between genotypes in their response to temperature and photoperiod. In many genotypes, flowering is photoperiod-insensitive, while the onset of podding is retarded by long photoperiods. In some genotypes both flowering and the onset of podding are delayed by long photoperiods. Podding may also be delayed by drought. The plant grows on any well-drained soil, but light sandy loams with a ph of are most suitable. Soils rich in phosphorus and potassium are suitable, but calcareous soils are not. Nitrogen-rich soils promote vegetative growth at the expense of seed yield. Sandy soils enhance pod penetration into the soil, but nematode incidence is generally higher on sandy than on loamy soils. Propagation and planting Bambara groundnut is propagated by seed. The seeds are orthodox and can be stored below 0 C. The seed weight is g; sowing rates range from kg/ha, depending on cropping system and climate. Seed to be sown is usually retained from the previous harvest or bought at local markets. Planting material is usually selected after harvesting on the basis of seed characteristics and not on plant characteristics. Often large seeds are selected for planting. Seeds are stored in bags, bottles, gourds or

214 216 CEREALS AND PULSES calabashes sometimes sealed with mud. They should be shelled just before sowing to retain maximum viability, but otherwise are rarely pretreated. Bambara groundnut is not usually sown immediately after the first rains, because staple food and cash crops tend to receive priority. Sowing dates vary considerably within locations. In Zambia and Botswana, for example, sowing takes place from November to February. Late sowing, however, may result in large yield reductions. Sometimes phased planting occurs, e.g. in Sukumaland, Tanzania. Land is cleared, and may be ploughed and ridged before sowing. In Botswana, fields are sometimes ploughed after the seed has been broadcast. The crop performs best on deeply ploughed fields with a fine seedbed, eventually allowing the plant to bury its developing fruits. Ridging is advisable if the soil is shallow or prone to waterlogging. Bambara groundnut may be sown on mounds, e.g. in Ghana. When sowing a new field, inoculation with soil from an old bambara groundnut field is recommended to promote nodulation with rhizobial bacteria. Bambara groundnut is sown in rows or broadcast; densities range from 2,500 plants/ha (intercropping in Botswana) to 250,000 plants/ha (sole cropping in Nigeria). Rows can be cm apart (Nigeria) to (-400) cm apart (Botswana). Spacings can be cm within rows (Nigeria) to cm (Botswana). Dry matter production of bambara groundnut is low, so high plant densities are recommended. However, high densities are only possible where rainfall and soil fertility are adequate. Furthermore, close spacing makes earthing up difficult. Seed is often dibbled, dropping 1-4 seeds in the hole and covering with soil. Sometimes a planter is used, or the seed is sown immediately behind a plough. Under rainfed conditions in sandy soils a sowing depth of at least 6 cm is advisable, but farmers often sow less deep. Thinning may be practised, often in combination with weeding. When establishment problems occur, gaps are sometimes filled in with seeds or plants thinned out elsewhere. Bambara groundnut may be grown in intercropping with cereals, other pulses, root and tuber crops, or vegetables. It is often grown together with maize, sorghum, pearl millet, groundnut and cowpea. Bambara groundnut is mainly grown by smallholders, often women, usually on small fields (less than 0.5 ha). Management Weeding of bambara groundnut takes place 1 3 times, often with a hoe. Earthing up to cover the young pods is common, and may be done by hand, with a hoe or with ox-drawn equipment. Earthing up improves yields, but is labour intensive; it is often combined with weeding. Nitrogen needs may be met by symbiotic nitrogen fixation. Nitrogen-fixation rates of up to 100 kg/ha have been reported, but sufficient phosphorus availability is essential for nodulation. The use of animal manure or chemical fertilizers is not common. Research in Botswana has shown that under the prevailing conditions nitrogen fertilization is not advisable, whereas phosphorus application is only beneficial when it is done close to the seedlings within 2 weeks of sowing and when the soil during this period is moist. Bambara groundnut is used in rotations, e.g. with maize, sorghum, pearl millet, cassava and yam. Farmers in Swaziland and in parts of South Africa prefer to sow bambara groundnut immediately after fallow, to maximize yields. Diseases and pests Although bambara groundnut is considered to be generally less affected by diseases and pests than groundnut or cowpea, several diseases and pests can cause serious damage to the crop. The most important fungal diseases are Cercospora leaf spot (Cercospora spp.), powdery mildew (Erysiphe polygoni) and Fusarium wilt {Fusarium oxysporum). Symptoms of Cercospora leaf spot are reddish-brown circular spots on the leaves, as well as lesions on the stems, petioles, peduncles and pods. The lesions may coalesce to give the appearance of blight. In cases of severe attack, defoliation occurs and plants may die prematurely. Crop rotation and burning of crop debris of the previous season are recommended to reduce damage, but the best solution is to use more resistant types. Symptoms of powdery mildew are a whitish powder on both sides of the leaves, especially on the upper surface. Infected leaves dry out and die. Treatment with a chlorothalonil-based fungicide has sometimes been effective. Fusarium wilt causes vascular discolouration, yellowing, necrosis and wilting and plants become stunted and eventually die. Crop rotation may help, but planting more resistant types is the best control. Other fungal pathogens affecting bambara groundnut include Macrophomina phaseolina (charcoal rot), Phomopsis sp.(blight), Phyllosticta spp. (Phyllosticta leaf spot) and Sclerotium rolfsii (southern blight and pod rot). Virus diseases include cowpea mottle virus (CPMoV), cowpea aphid-borne mosaic virus

215 VIGNA 217 (CABMV) and peanut mottle virus (PeMoV). Genotypes resistant to cowpea mottle virus have been identified. Root-knot nematodes (Meloidogyne incognita, Meloidogyne javanica) can seriously affect yields. Pests of germinating seeds include rodents, termites, ants and cutworms (Agrotis). The standing crop may be attacked by insect pests such as aphids, groundnut jassid (Empoasca facialis), groundnut hopper (Hilda patruelis), brown leaf beetle (Ootheca mutabilis), and bean leaf webber (Hedylepta indicata, synonym: Lamprosema indicata). A serious pest in Swaziland is the American bollworm (Helicoverpa armigera). Control measures of insect pests include the use of insecticides, e.g. malathion against aphids. Leaves may also be eaten by mammals, such as duikers. Maturing seeds may be attacked by rodents, ants, wild pigs, monkeys and bush babies (Galago spp.). Important storage pests are the bruchid beetles Callosobruchus maculatus and Callosobruchus subinnotatus, and the maize weevil Sitophilus zeamais. Infestation often begins in seeds ripening in the field and is later carried into the stores. Seeds stored in the pod shell suffer less from deterioration and infestation by insects than shelled seeds. Stored seeds are sometimes protected by applying ash, chemical products (malathion, carbamyl) or plant products, such as ground tobacco leaves, ground peppers or the leaves of basil (Ocimum basilicum L.). The parasitic plants Alectra vogelii Benth. and Striga gesnerioides (Willd.) Vatke may reduce yields considerably. Harvesting Bambara groundnut is harvested days after sowing, depending on genotype, ecological conditions and farmers' objectives. As the seeds may be consumed either unripe or ripe, different harvesting methods exist. Unripe seeds may be harvested in several rounds from the same plants. Mature seeds are harvested when the leaves turn yellow and fall, and when the pods have become hard. In the latter case, harvesting is usually done by uprooting the plants by hand or with a hoe. The leaves are left in the field or fed to animals. Yield Yield fluctuations between years are large in bambara groundnut and mainly depend on rainfall. The highest recorded seed yield under field conditions is 4 t/ha. Average yields are kg/ha, but yields of less than 100 kg/ha are not uncommon. Bambara groundnut still gives some yield under conditions (poor soils, drought) which are submarginal for groundnut. Handling after harvest The pods of bambara groundnut are sun-dried to a moisture content of 12% and stored in bags or drums in granaries or in the house. They may be shelled first with mortar and pestle, flails or modified groundnut shellers. The shelling percentage ranges from 70-77% by pod weight. Bambara groundnut is a typical dual-purpose crop: usually part of the harvest is sold and the rest is kept for own consumption. Canning of bambara groundnut seeds has been done in Ghana and Zimbabwe. Genetic resources The largest germplasm collection of bambara groundnut (2000 accessions from sub-saharan Africa) is held by UTA (International Institute of Tropical Agriculture), Ibadan, Nigeria. Most of the accessions (1400) in this collection have been characterized, evaluated and documented. Other large collections are found at the IRD (Institut de Recherche pour le Développement), Montpellier, France (about 1200 cultivated and 60 wild accessions from Cameroon, of which 50 were morphologically characterized), the University of Zambia, Lusaka, Zambia (460 accessions), the Grain Crops Institute, Potchefstroom, South Africa (200 accessions) and the Plant Genetic Resources Centre, Accra, Ghana (170 accessions). In many African countries smaller collections are maintained. In studies of genetic diversity in cultivated bambara groundnut with RAPD and AFLP markers, considerable genetic variation was found, with accessions clustering mainly according to their geographical origin. Sometimes, e.g. in Swaziland, farmers sow a mixture of landraces as a buffer to biotic and abiotic stresses, thus helping to maintain the diversity of the crop. Breeding Bambara groundnut breeding has mainly been confined to selection between and within populations for yield, disease resistance (Fusarium wilt and Cercospora leaf spot) and drought tolerance. From the UTA germplasm collection genotypes have been identified with a longer and denser root system, which may be useful in breeding for drought tolerance. Breeding of genotypes with a shorter growth period also seems useful for drier regions. Selection of the most effective combinations of genotypes and rhizobial strains seems promising to improve nitrogen fixation and increase crop yields. Artificial hybrids between cultivated genotypes and between cultivated and wild accessions

216 218 CEREALS AND PULSES have been made in the United Kingdom and Swaziland, but success rates are generally low. A genetic linkage map of bambara groundnut using AFLP markers is being developed in the United Kingdom as well. Micropropagation of bambara groundnut is possible using stem nodal cuttings or embryo axes. Prospects Bambara groundnut is a suitable crop for semi-arid regions, because it tolerates drought and poor soil conditions and appears to be less affected by diseases and pests than cowpea or groundnut. Farmers also value its multiple uses and good taste. Although bambara groundnut will remain an important secondary food crop in Africa, the area under cultivation will probably decline, because of high labour requirements, especially for earthing up and harvesting, the absence of an export market outside Africa, and the competition from groundnut and cowpea. The prospects of bambara groundnut as a food crop can be improved by developing high-yielding cultivars with improved disease resistance and lower antinutritional factors. The development of new food product composites with cereals may also lead to increased use of the crop. Major references Anchirinah, Yiridoe & Bennett-Lartey, 2001; Brink, 1998; Brink, Collinson & Wigglesworth, 1997; Heller, Begemann & Mushonga (Editors), 1997; Linnemann, 1989; Linnemann, 1994; Linnemann & Azam-Ali, 1993; Massawe et al., 2003; Pasquet, Schwedes & Gepts, 1999; Sesay, Saboleh & Yarmah, Other references Allen & Lenné, 1998; Amarteifio, Karikari & Moichubedi, 1998; Azam-Ali (Editor), 2003; Azam-Ali et al, 2001; Burkill, 1995; Collinson et al, 1997; Dijkstra et al., 1995; Doku & Karikari, 1971; du Puy et al., 2002; FAO, 1970; Gillett et al., 1971; Goli, 1997; Kannaiyan & Haciwa, 1993; Lacroix, Assoumou & Sangwan, 2003; Leung, Busson & Jardin, 1968; Linnemann, 1988; Linnemann, 1990; Massawe, Azam Ali & Roberts, 2003; Ofori, Kumaga & Bimi, 2001; Ramolemana, Sources of illustration Linnemann, Authors M. Brink, G.M. Ramolemana & K.P. Sibuga VlGNAUMBELLATA (Thunb.) Ohwi & H.Ohashi Protologue Journ. Jap. Bot. 44(1): 31 (1969). Family Papilionaceae (Leguminosae - Papilionoideae, Fabaceae) Chromosome number 2n = 22 Synonyms Phaseolus calcaratus Roxb. (1832), Vigna calcarata (Roxb.) Kurz (1876). Vernacular names Rice bean, red bean, climbing mountain bean (En). Haricot riz (Fr). Feijào arroz (Po). Origin and geographic distribution Rice bean originates from Asia, where it is found wild from India and central China through Indo-China to Malaysia. It was introduced by the Arabs into Egypt, along the eastern coast of Africa and to the Indian Ocean islands. Nowadays, rice bean is widely cultivated in tropical Asia, and to a more limited extent in Fiji, the United States, Australia, southwestern Asia and tropical Africa and America. In tropical Africa it is grown in West Africa, East Africa and the Indian Ocean islands, and less frequently in Central and southern Africa. Uses Mature, dry rice bean seeds are eaten as a pulse. They are usually boiled and eaten with rice or instead of rice, often in soups or stews, e.g. in Ghana. In Madagascar flour of dried germinated rice bean seeds is included in complementary foods for children. Rice bean is not very popular in India, because it cannot easily be processed into dhal as it contains a fibrous mucilage, which prevents easy hulling and separation of the cotyledons. The leaves, young pods and sprouted seeds of rice bean are eaten boiled as a vegetable. In Vigna umbellata - planted

217 VlGNA 219 India the young pods are sometimes eaten raw. The whole plant is used as fodder and made into hay and silage. The seeds are sometimes used as feed for livestock. Rice bean is also sown as a cover crop, green manure and living hedge. Production and international trade Rice bean production statistics are not available, but the crop is mainly produced in tropical Asia. Little of the rice bean production enters international trade. Japan is the main importer; the main exporters are Thailand, Myanmar and China. Madagascar also exports some rice bean; its average annual export in has been estimated at 1100 t. Properties The composition of dried rice bean seeds per 100 g edible portion is: water 13.3 g, energy 1369 kj (327 kcal), protein 20.9 g, fat 0.9 g, carbohydrate 60.7 g, fibre 4.8 g, Ca 200 mg, P 390 mg, Fe 10.9 mg, thiamin 0.49 mg, riboflavin 0.21 mg and niacin 2.4 mg (Leung, Busson & Jardin, 1968). The Ca content is high compared with other pulse crops, and rice bean is considered good for lactating mothers. Antinutritional factors in rice bean include trypsin-inhibiting factors, phytates, tannins and oligosaccharides. Soaking, sprouting, hulling and cooking can reduce these antinutritional factors considerably. Rice bean seeds do not contain cyanogenic glycosides. Protein concentrates prepared from rice bean seeds have shown in vivo anti-hypercholesterolaemic effects in hamsters. A peptide isolated from rice bean seeds has shown strong antifungal activity against Botrytis cinerea, Fusarium oxysporum, Rhizoctonia solani and Mycosphaerella arachidicola. Furthermore, it has shown mitogenic and anti-hrv-1 reverse transcriptase activity. In the vegetative stage the rice bean plant (moisture content 84%) contains on a dry matter basis: 18.0% crude protein, 1.1% fat, 31.5% crude fibre, 39.9% N-free extract, 9.5% ash, 1.4% Ca and 0.35% P. In the flowering stage (moisture content 76%) it contains on a dry matter base: 14.5% crude protein, 1.0% fat, 32.1% crude fibre, 41.6% N-free extract, 10.8% ash, 1.2% Ca and 0.4% P. Its vigorous vegetative growth makes rice bean suitable for use as a cover crop and green manure. Description Annual climbing herb, with stems up to 3 m long; stem grooved, usually clothed with fine, deciduous, deflexed hairs; taproot up to 1.5 m long. Leaves alternate, trifoliolate; stipules lanceolate, c. 1.5 cm long; petiole 5-10 cm long; stipels linear-lanceolate, Vigna umbellata branch; 2, seeds. Source: PROSEA 1, flowering and fruiting c. 0.5 cm long; leaflets broadly ovate to ovatelanceolate, 5-10(-13) cm x 1.5-6(-7) cm, entire or 2-3-lobed, the lateral leaflets unequal-sided, membranous, almost glabrous. Inflorescence an erect axillary false raceme, 3-10 cm long, 5-20-flowered, with flowers usually in pairs; peduncle up to 20 cm long. Flowers bisexual, papilionaceous; pedicel c. 5 mm long; calyx campanulate, c. 4 mm long, 5-toothed; corolla bright yellow, standard cm in diameter; wings large and broad, enclosing the keel; keel with a curved beak and a conical pocket on one side; stamens 10, 9 connate into a tube, upper one free; ovary superior, 1-celled, style broadened and curved. Fruit a linear-cylindrical pod, 6-13 cm x cm, deflexed, glabrous, green when young, black-brown at maturity,6 8(-16)-seeded. Seeds oblong, 5-10 mm x 2-5 mm x 3-4 mm, smooth, yellow, green, dark red, brown, black, speckled or mottled; hilum excentric, elongate, hidden by a cream-coloured rim. Seedling with hypogeal germination. Other botanical information Vigna comprises about 80 species and occurs throughout the tropics. However, the tropical American species are likely to be placed in a separate genus in the near future, which would reduce

218 220 CEREALS AND PULSES the genus to species. Vigna umbellata forms part of the subgenus Ceratotropis, which also includes Vigna radiata (L.) R.Wilczek (mung bean), Vigna mungo (L.) Hepper (black gram), Vigna angularis (Willd.) Ohwi & H.Ohashi (adzuki bean) and Vigna aconitifolia (Jacq.) Maréchal (moth bean). Vigna umbellata is closely related to Vigna angularis, with which it can be crossed using embryo culture and with rice bean as the female parent. Vigna minima (Roxb.) Ohwi & H.Ohashi, a wild species from tropical Asia, is even more closely related to Vigna umbellata. Within Vigna umbellata 2 types have been distinguished, commonly designated as varieties: - var. gracilis (Prain) Maréchal, Mascherpa & Stainier, the wild type with slender branchlets, narrow leaflets and long peduncles, found from India to Malaysia, the Philippines and central China. This taxon closely resembles Vigna minima, or should even be united with it. var. umbellata, the cultivated types. Cultivars have mainly been identified on the basis of maturity period and seed colour. In Madagascar 2 types are distinguished: yellow rice bean ('tsiasisa mavo') and red rice bean ('tsiasisa mena'). Growth and development Rice bean seedlings grow vigorously and establish themselves quickly. In Madagascar time to flowering is70 75 days, time to seed maturity days. In Angola the time from sowing to maturity can be as short as 60 days. In the Philippines time to flowering averages 64 days, to maturity 92 days; in India early-maturing types behave likewise, whereas late types ripen in days. Flowers are self-compatible, but crosspollination also occurs. Ecology Rice bean is typically suited to humid tropical lowlands, but some cultivars are adapted to subtropical or temperate conditions.