EVALUATION OF SPRING FORAGE PEA VARIETIES BY QUALITY RELATED CHARACTERISTICS Anna ILIEVA, Valentin KOSEV Institute of Forage Crops 5800 Pleven, Gen. Vl. Vazov. 89. Bulgaria e mail: anna_ibg@yahoo.com DOI: 10.7904/2068 4738 IV(8) 54 Abstract. In 2008 2010 in the Second Experimental Field of the Institute of Forage Crops Pleven, a comparative field trial was carried out with 6 Bulgarian and 3 Ukrainian varieties of spring forage pea (Pisum sativum ssp. sativum L.). Variety Pleven 4 was used as a standard. A biochemical assessment of the aboveground biomass of the varieties was made by following characteristics: content of crude protein, crude fiber, calcium, and phosphorus and water soluble sugars. The results of the study showed that, in comparison with standard, Bulgarian varieties Amitie, Pikardi, Kerpo and Kristal had the best values of the analyzed characteristics in the aboveground biomass. These varieties were distinguished for comparatively high content of crude protein and water soluble sugars and low content of crude fiber. At both phenological stages (budding and full maturity) statistically significant correlational relationships were established positive between the content of crude protein and phosphorus (r=0.503; r=0.436) and negative between crude fiber and crude protein (r= 0.419; r= 0.721), between crude fiber and water soluble sugars (r= 0.573; r= 0.723) and between calcium and phosphorus (r= 0.522; r= 0.536). Keywords: spring forage pea, aboveground biomass, biochemical assessment Introduction Increasing the content of vegetable protein in forages remains one of the most important issues. The significant role in solving this issue belongs to grain leguminous crops, including pea [АNISIMOV, 2009]. Spring forage pea (Pisum sativum ssp. sativum L.) is a very valuable and widespread crop. In last years in Bulgaria new high productive varieties of spring forage pea have [МIHOV et al., 2005; КЕRTIKOVA et al., been developed 2009]. The importance of this crop to agriculture is due to the large productive capacities of the contemporary varieties having valuable nutritive qualities, high content of protein, sugars and major nutrients in grain and whole plant, to its multi purpose use, to its great plasticity and diversity of forms, which make it possible to grow pea under different climatic conditions [АNGELOVA, 1995, 2005; КЕRTIKOV et al., 2003; ТОDOROVA et al., 2007; NANKOV, 2009]. As a nitrogen fixing crop, pea is of great importance also to natural soil fertility. Its inclusion in crop rotation schemes as a preceding crop for other crops decreases the nitrogen fertilizing to a great extent, which is particularly important in organic farming [АNGELOVА, 2006; VASILEVA, 2006]. The whole pea plant can be used to make silage, haylage, hay or dehydrate [MCPHEE, 2003; КIRILOV, 2005]. When selecting initial forms for breeding, in addition to morphological and productive features, increasingly great attention is paid to quality related characteristics determining nutritive value of forage. Genotypes combining high nutritive quality and high yield are searched for. In selection for quality related characteristics it is important to clarify variability in content of chemical compounds determining qualitative composition of forages [МIKA, 1988; NOVIKOVA, 1996; BUXTON, 1996]. The objective of this study was to make a biochemical assessment of aboveground biomass of spring forage pea varieties with a view to their use as parental components in the breeding programs. 54
Banat s University of Agricultural Sciences and Veterinary Medicine "Regele Mihai I al României" from Timisoara Contact: web: http://www.bjbabe.ro, e-mail: bjb@usab tm.ro Material and methods In period of 2008 2010 in the Second Experimental Field of the Institute of Forage Crops Pleven, a comparative field trial was laid out by block method with four replications and a size of experimental plot of 5 m 2. Sowing was conducted at the optimal dates for the crop according to the adopted technology for growing spring pea in the Institute of Forage Crops Pleven, at the sowing rate of 120 germinable seeds / m 2, with an inter row spacing of 11 cm and a sowing depth of 5 cm. Plant material from aboveground biomass of 9 spring varieties of forage pea was analyzed. Varieties Pleven 4 (standard), Kristal, Pikardi, Amitie, Drujba, Kerpo originate from Bulgaria, and Usatyi 90, Rezonator and Harskovskii Etalonnyi originate from Ukraine. The samples were taken at two phenological stages of plant development budding and full (technical) maturity. A biochemical assessment of varieties was made by following characteristics: content of crude protein (CP) by the method of Kjeldahl, crude fiber (CF) by Weende method, calcium and phosphorus according to [SANDEV, 1979], and water soluble sugars according to [ERMAKOV et al., 1987]. The relationships between characteristics were established by a correlation analysis [DIMOVA and MARINKOV, 1999]. The statistical processing of experimental data was performed by the programmes Excel of Microsoft Office 2002 and Statgraphics Plus 2.1 for Windows. Results and discussion The average data for three years showed that at the budding stage content of crude protein in aboveground mass of studied varieties of spring forage pea varied from 15.26% tо 20.19% (Table 1). Table 1. Biochemical assessment of the spring forage pea varieties (average 2008 2010) Variety CP CF Са Р WSC % of dry % toward % of dry % toward % of dry % toward % of dry % toward % of dry matter st. matter st. matter st. matter st. matter % toward st. Budding Pleven 4 st 17.28 abc 100.00 19.34 bc 100.00 1.003 ab 100.00 0.244 a 100.00 12.73 ab 100.00 Amitie 20.10 de 116.3 14.19 a 73.4 0.987 ab 98.4 0.316 cde 129.5 13.27 ab 104.2 Pikardi 20.19 de 116.8 13.15 a 68.0 0.902 a 89.8 0.366 e 150.0 15.07 b 118.4 Harskovskii Etalonnyi 17.44 abc 100.9 22.33 c 115.5 1.151 b 114.7 0.282 abc 115.6 12.43 a 97.6 Usatyi 90 15.26 a 88.3 20.19 bc 104.4 0.999 ab 99.6 0.237 a 97.1 13.23 ab 103.9 Kristal 17.95 bcd 103.9 17.94 b 92.8 1.100 ab 109.7 0.253 ab 103.7 13.17 ab 103.4 Drujba 16.87 ab 97.6 19.63 bc 101.5 0.997 ab 99.4 0.279 abc 114.3 12.53 a 98.4 Kerpo 16.77 ab 97.0 14.05 a 72.6 1.018 ab 101.5 0.281 abc 115.2 13.70 ab 107.6 Rezonator 16.94 ab 98.0 20.15 bc 104.2 1.138 b 113.4 0.305 bcd 125.0 12.57 a 98.7 LSD 0.05 2.272 3.553 0.224 0.059 2.337 Full maturity Pleven 4 st 16.39 abc 100.00 21.12 bcde 100.00 0.946 ab 100.00 0.335 ab 100.00 2.07 abc 100.00 Amitie 17.00 bc 103.7 17.08 ab 80.9 0.920 ab 97.2 0.332 ab 99.1 2.57 bc 124.1 Pikardi 16.34 abc 99.7 16.13 a 76.4 0.884 ab 93.4 0.326 ab 97.3 2.13 abc 102.9 Harskovskii Etalonnyi 14.87 ab 90.7 24.55 е 116.2 1.041 ab 110.0 0.272 a 81.2 1.57 ab 75.8 Usatyi 90 15.10 abc 92.1 21.73 cde 102.9 1.106 ab 116.9 0.351 ab 104.8 1.93 abc 93.2 Kristal 17.35 c 105.8 17.66 abc 83.6 1.163 b 122.9 0.349 ab 104.2 2.40 bc 115.9 Drujba 14.42 a 88.0 22.59 de 107.0 1.069 ab 113.0 0.270 a 80.6 1.23 a 59.4 Kerpo 15.83 abc 96.6 19.30 abcd 91.4 1.021 ab 107.9 0.284 ab 84.8 2.63 c 127.0 Rezonator 16.50 abc 100.7 20.32 abcde 96.2 1.000 ab 105.7 0.290 ab 86.6 2.23 abc 107.7 LSD 0.05 2.263 4.371 0.234 0.098 1.048 a, b, c, statistically significant differences at P=0.05 CP Crude protein, CF Crude fiber; WSC water soluble carbohydrate, % DM % of dry matter, st standard; Varieties Amitie (20.10%) and Pikardi (20.19%) statistically significantly exceeded the standard variety Pleven 4 (17.28%) in this trait. In varieties Kristal (17.95 %) and Harskovskii Etalonnyi (17.44%) exceeding over standard was statistically nonsignificant, 55
and varieties Drujba (16.88%), Кеrpо (16.77%) and Rezonator (16.94%) were close to standard in content of crude protein. The lowest content of crude protein was established in variety Usatyi 90 15.26%. The content of crude fiber varied within wide limits from 13.15% tо 22.33 % (Table 1). In comparison with standard (19.34%), the lowest content of crude fiber was recorded in varieties Pikardi (13.15%), Кеrpо (14.05%) and Amitie (14.19%) with statistically significant differences at Р=0.05. The content of crude fiber in variety Kristal was lower than standard by 7.2 %, but decrease was statistically nonsignificant. Varieties Harskovskii Etalonnyi, Usatyi 90, Drujba and Rezonator exceeded standard in this trait, but differences were statistically nonsignificant. The highest content of crude fiber was established in variety Harskovskii Etalonnyi 22.33%. The content of calcium and phosphorus in the plants had an influence on the nutritive value of forage, and hence on the productivity and health status of animals. The content of calcium in aboveground biomass of studied varieties varied from 0.902% in Pikardi to 1.15% in Harskovskii Etalonnyi. Results showed that differences between varieties and standard (1.003 %) were statistically nonsignificant (Р=0.05). All varieties, participating in this study, except for Usatyi 90, exceeded standard in content of phosphorus, but only in Amitie (0.316%), Pikardi (0.366%) and Rezonator (0.305%) exceeding was statistically significant (Table 1). The content of water soluble sugars varied from 12.43 % in variety Harskovskii Etalonnyi tо 15.07 % in variety Pikardi. In the terms of content of water soluble sugars, variety Pikardi exceeded standard (12.73 %) by 18.4 %; variety Kerpo by 7.6 %. With advance of vegetation from budding stage to full maturity stage, content of crude protein in aboveground biomass decreased, and that of crude fiber increased (Table 1). At the full maturity stage content of crude protein in aboveground biomass varied from 14.42% (variety Drujba) tо 17.35% (variety Kristal). No statistically significant differences, as against standard variety Pleven 4 (16.39%), were established for any of studied varieties. Varieties Amitie (17.08 %), Pikardi (16.13 %), Кristal (17.66 %) and Кеrpо (19.30 %) had lower content of crude fiber than standard (21.12 %), but only in variety Pikardi difference was significant (Р=0.05). The obtained values of content of calcium and phosphorus varied slightly and did not differ significantly from standard. At the full maturity stage content of water soluble sugars considerably decreased as compared to budding stage. The highest content of sugars at this stage was established in varieties Kerpo (2.63 %), Аmitiе (2.57 %) and Kristal (2.40 %). The correlational relationships between the studied parameters were established. Table 2. Correlations between the investigated parameters (at phenological stage of budding) CP CF Са Р CF 0.419* Са 0.095 0.073 Р 0.503** 0.332 0.522** WSC 0.001.573** 0.384* 0.315 *significant at 0.05; **significant at 0.01 At budding stage following relationships were well expressed and statistically significant at Р=0.05 and Р=0.01: positive between crude protein and phosphorus (r=0.503) and negative between crude protein and crude fiber (r= 0.419), phosphorus and calcium (r= 0.522); water soluble sugars and crude fiber (r= 0.573) (Table 2). 56
Banat s University of Agricultural Sciences and Veterinary Medicine "Regele Mihai I al României" from Timisoara Contact: web: http://www.bjbabe.ro, e-mail: bjb@usab tm.ro At full maturity stage obtained relationships were analogous. Table 3. Correlations between the investigated parameters (at phenological stage of full maturity) CP CF Са Р CF 0.721** Са 0.259 0.153 Р 0.436* 0.245 0.536** WSC 0.358 0.723** 0.344 0.167 *significant at 0.05; **significant at 0.0 Between crude protein and phosphorus relationship was positive, moderate (r=0.436), and between phosphorus and calcium it was negative and considerable (r= 0.536). Between crude fiber and crude protein (r= 0.721) (Table 3) and water soluble sugars and crude fiber (r= 0.723) relationships were negative and high. Conclusions The results of study showed that, in comparison with standard, Bulgarian varieties Amitie, Pikardi, Kerpo and Kristal had best values of analyzed characteristics in aboveground biomass. These varieties were distinguished for comparatively high content of crude protein and water soluble sugars and low content of crude fiber. At both phenological stages (budding and full maturity) statistically significant correlational relationships were established positive between content of crude protein and phosphorus (r=0.503; r=0.436); negative between crude fiber; crude protein (r= 0.419; r= 0.721), between crude fiber and water soluble sugars (r= 0.573; r= 0.723) and between calcium and phosphorus (r= 0.522; r= 0.536). References 1. Anisimov, A.; Influence of inoculation on the productivity of pea varieties in the conditions of Novgorod district. Author s abstract of dissertation for conferment of PhD degree in Agriculture, 2009. 2. Аngelovа, S.; Protein crops are mothers of fertility. Farmer, 2006, 05.06. 3. Аngelovа, S.; Value for cultivation and use of local and introduced pea varieties, Plant Science, 1995, 1 2:49 151. 4. Аngelovа, S.; What is the news about spring forage pea? Agriculture Plus, 2005, 3: 9 10. 5. Buxton, D.; Quality related characteristics of forages as influenced by plant environment and agronomic factors. Animal feed science and technology, 1996, 59(1 3):37 49 6. Dimova, D.; Marinkov, E.; Experimental works with biometr, S., Zemizdat, 1999. 7. Ermakov, A.; Arasimovich, V.; Yarosh, N.; Peruanskii, Yu. Lukovnikova, G.; Ikonomova, M.; Methods for biochemical study of plants. Agropromizdat, М. 1987, pp. 134 135. 8. Наnkov, М.; Grain yield and qualities of spring pea grown in a four field crop rotation. International Science Conference Economics and Society Development in the Base of Knowledge Stara Zagora, 2009, 1:441 444. 9. Kertikov, T. and coauthors; Spring Forage Pea. Brochure. Agriculture Plus 1. 2003. 10. Kertikova, D.; Kertikov, T.; Popov, I.; Kerpo a new variety of spring forage pea. Journal of Mountain Agriculture on the Balkans, 2009, 12(2):342 348 11. Kirilov, A.; Opportunities for using grain from leguminous crops as a source of protein in the rations for ruminant animals. Scientific Reports. Jubilee Scientific Conference Breeding and Technological Aspects in Production and Processing of Soybean and Other Leguminous Crops, 2005, pp. 175 180. 12. McPhee, K.; Dry pea production and breeding A mini review, Food, Agriculture and Environment, 2003, 1(1):64 69. 13. Мihov, М.; Аtanasovа, D.; Stоyanovа, М. Kristal a new variety of spring forage pea (Pisum sativum L.) for grain. Book of Reports from the Jubilee Scientific Conference (JSC) Breeding and Technological Aspects in Production and Processing of Soybean and Other Leguminous Crops, Pavlikeni, 2005, pp. 276 280. 14. Mika, V.; Effective evaluation of quality of herbaceous forages in the breeding 57
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