Fungi associated with fruit rots of Actinidia chinensis Hort16A in New Zealand

Transcription

1 New Zealand Journal of Crop and Horticultural Science ISSN: (Print) (Online) Journal homepage: Fungi associated with fruit rots of Actinidia chinensis Hort16A in New Zealand M. A. Manning, X. Meier, T. L. Olsen & P. R. Johnston To cite this article: M. A. Manning, X. Meier, T. L. Olsen & P. R. Johnston (2003) Fungi associated with fruit rots of Actinidiachinensis Hort16A in New Zealand, New Zealand Journal of Crop and Horticultural Science, 31:4, , DOI: 1080/ To link to this article: Published online: 22 Mar Submit your article to this journal Article views: 633 Citing articles: 11 View citing articles Full Terms & Conditions of access and use can be found at

2 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31: /03/ $7.00 The Royal Society of New Zealand Fungi associated with fruit rots of Actinidia chinensis 'Hort16A in New Zealand M. A. MANNING X. MEIER T. L. OLSEN The Horticulture and Food Research Institute of New Zealand Ltd Mt Albert Research Centre Private Bag Auckland, New Zealand P. R. JOHNSTON Landcare Research Private Bag Auckland, New Zealand Abstract A new yellow fleshed kiwifruit Actinidia chinensis var. chinensis 'Hort16A' grown commercially in New Zealand is susceptible to infection by several fungi. The symptoms are mainly apparent after a period in coolstorage although preharvest symptoms do occur. Botryosphaeria dothidea, Cryptosporiopsis sp., Diaporthe spp., Cylindrocarpon cf. candidum, Phoma exigua, and Botrytis cinerea have most commonly been isolated from a range of symptoms on fruit including side, distal end and stem end rots, and fungal pitting. In addition, wounds caused by postharvest fruit handling can become infected. During trials to establish the best methods of postharvest handling and storage, identifications of fungi associated with fruit rots were made. This paper outlines the observations of several years of study on diseases of 'Hort16A' kiwifruit and describes the symptoms and the fungi associated with them. H03077; Online publication date 3 November 2003 Received 13 August 2003; accepted 29 August 2003 Keywords Actinidia chinensis var. chinensis 'Hort16A'; kiwifruit; fungal diseases; Botrytis; Botryosphaeria; Cryptosporiopsis; Diaporthe; Phoma; Cylindrocarpon INTRODUCTION Yellow fleshed kiwifruit Actinidia chinensis Planch, var. chinensis 'Hort16A' is a cultivar introduced by The Horticulture and Food Research Institute of New Zealand Ltd and marketed by ZESPRI International Ltd to complement the production of Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson var. deliciosa 'Hay ward'. In New Zealand, commercial planting of 'Hort16A' in the late 1990s produced sufficient quantities of this cultivar for export by Grafting of 'Hort16A' onto mature 'Hayward' stumps reduced the time from orchard establishment to export production. From 2000 onwards, increased production of 'Hort16A' resulted in large volumes of fruit becoming available for export and a need for the marketing period to be extended. The marketing period of 'Hayward' is generally 20 weeks and fruit quality is maintained during this time in coolstorage. However in some orchard lines, the storage of 'Hort16A' at 0-2 C is limited to c. 12 weeks by the development of rots. The fruit are mainly affected by rots appearing during storage (storage rots), although preharvest rots do sometimes occur. The complex of fungi associated with 'Hort16A' is similar to that associated with 'Hayward' although the commercial importance of particular species differs between the two crops. In this paper, fungi and their symptoms on 'Hort16A' are described and some comparison with diseases of 'Hayward' are made. Although the associations of fungi with preharvest rots are discussed, the majority of fungi described are associated with rots developing on fruit in storage.

3 316 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31 METHODS Isolation results presented in this paper have been compiled from 16 research trials conducted between 1999 and Fruit were commercially grown and harvested from a number of orchards in the Northland, Auckland, and Bay of Plenty growing districts in the North Island, New Zealand. Preharvest conditions varied between trials. However, in all trials, harvested fruit were placed in coolstorage (0-2 C) for up to 24 weeks and regularly assessed for rots. At assessment, rots were categorised according to the location of the affected area as distal end (DER), stem end (SER) and side rots (SR) or alternatively, as wound rots (WR) or fungal pits (FP). Distal end rots are first detected as a softness and collapse of the distal end (also called the "beak") of 'Hort16A'. Stem end rots are centred on the picking wound and side rots occur between the stem end and distal end of fruit. Wound rots are classified as an infection around a beak puncture, cut or physical damage to the skin. Fungal pits tend to be sharp-edged, often solitary pits with a pale yellow centre on the fruit surface. This fungal symptom is similar to a disorder called physiological pitting, although fungal pits are usually larger, paler, and more deeply indented. Isolations were made after assessments to determine the identity of associated fungi. The affected tissue of a sample of fruit with rot was exposed by peeling back the fruit skin and extracting small pieces of the underlying rotted tissue on to DIFCO prune or potato dextrose agar. Isolation plates were incubated at ambient temperature under cycles of 12 h darkness : 12 h near-ultra violet and visible illumination ("BLB" and "Cool White" fluorescent tubes). A selection of isolates recovered from 'Hort16A' and held in the Landcare Research International Collection of Micro-organisms from Plants (ICMP) was used to estimate the growth rate of fungi associated with 'Hort16A'. A 4 mm plug from a culture of each isolate was placed into the middle of DIFCO potato dextrose agar plates (PDA). Three plates from each isolate were subcultured in this manner and grown in darkness at 0 C and 20 C. Radial growth was measured at regular intervals. Measurement was terminated after 141 days. Growth rate was calculated on the linear section of growth curves for each isolate and are based on differing Table 1 Fungal species isolated from rots of 'Hort16A' Actinidia chinensis var. chinensis fruit. Data are presented as percentage of total isolations within each symptom category: distal end rots (DER), fungal pitting (FP), stem end rots (SER), side rots (SR), and wound rots (WR) from several trials over a 3-year period ( ). Fungi causing major diseases in fruit of 'Hort16A' are in bold. (N/A, not applicable.) DER (%) FP (%) SER (%) SR (%) WR (%) Appearance in coolstorage (week) Alternaria sp. Botryosphaeria dothidea Botryosphaeria parva Botrytis cinerea Cladosporium sp. Colletotrichum acutatum Cryptosporiopsis sp. Cylindrocarpon cf. candidum Diaporthe spp. Epicoccum sp. Fusarium spp. Mucor piriformis Penicillium spp. Pestalotiopsis sp. Pezicula spp. Phialophora sp. Phoma exigua Other unidentified species No growth* Total isolations (N) >12 >6 >6 >15 >12 >16 >16 >16 >16 >12 >15 N/A N/A *No growth = no fungi recovered from tissue sample.

4 Manning et al. Fungi associated with 'Hort16A' rots in NZ 317 numbers of cultures and replicates per species. Data are presented as the average growth rate (mm/day) for each isolate. Standard errors of the means are also presented. Descriptions refer to culture appearance at 10 days. RESULTS AND DISCUSSION The results of isolations from rots of 'Hort16A' from and the approximate time of symptom expression for each fungus are presented in Table 1. Growth rates on PDA for each fungal culture at 0 C and 20 C are presented in Table 2. Growth rates at 20 C are presented for identification purposes whereas 0 C data provide an indication of behaviour of fungi in coolstorage. Most fungi grow poorly at 0 C and consequently, appear after long-term storage (Table 1). Botrytis cinerea is a relatively fast growing fungus at low temperatures and therefore, rots associated with B. cinerea are observed earlier in coolstorage (8 weeks). Although Botryosphaeria dothidea did not grow on PDA at 0 C, this fungus was isolated from rot symptoms appearing after 6 weeks of coolstorage. This illustrates the difference between growth on media and fruit. However, it is felt that the test is fairer on media as the fruit/pathogen interaction is removed (Brooks & Cooley 1917). Table 2 Mean growth rates (mm/day) of fungal cultures grown at 0 C and 20 C on potato dextrose agar in darkness with the standard error of the mean given in parentheses. Accession numbers refer to isolates lodged with the International Collection of Micro-organisms from Plants (ICMP) Landcare Research, Auckland, New Zealand. Fungal species Accession no. Growth rate at 0 C (mm/day) Growth rate at 20 C (mm/day) Botryosphaeria dothidea Botrytis cinerea Colletotrichum acutatum Cryptosporiopsis sp. Cylindrocarpon cf. candidum Diaporthe spp. Pezicula spp. Phialophora sp. Phoma exigua Sclerotinia sclerotiorum No growth at 0 C No growth at 0 C 1.77 (42) 1.25 (69) 0.64 (13) 1.25 (36) 5 (03) 3 (16) 2 (08) 1 (03) 5 (02) 7 (02) 4 (05) 3 (08) 0.28 (05) 0.29 (02) 1 (04) 0.26 (03) 2 (00) 6 (09) 0.20 (06) 0.29 (04) 1 (02) 6 (02) 9 (02) 7 (01) 2 (07) 2 (15) 6 (04) 1 (08) 7 (02) 4 (45) (37) (56) (0.978) (44) (0.500) (83) (31) (45) (55) (29) (24) (41) (40) (35) (19) (25) (51) (23) (67) (0.298) (73) (79) (0.220) (17) (04) (09) (40) (09) (90) (28) (25) (4.630)

5 318 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31 Fig. 1 Botryosphaeria dothidea on Actinidia chinensis var. chinensis fruit. A, Brown, sunken dimple (c. 3 mm). B, Rot with characteristic "thumbprint" symptom. Descriptions of the major diseases caused by fungal species in fruit of 'Hort16A' Botryosphaeria dothidea (Moug.) Ces. & De Not. On PDA plates, B. dothidea (anamorph: Fusicoccum aseculi Corda) appears green and cottony with a greyish underside. Hawthorne et al. (1982) and Pennycook & Samuels (1985) provide a full description of this fungus. The first symptoms of B. dothidea on 'Hort16A' appear as shallow brown dimples (Fig. 1A). These develop into pale brown oval lesions c mm long and larger rots with a dark green margin (Fig. 1B). These symptoms are similar to those described by Pennycook (1985) and Pennycook & Samuels (1985) on 'Hayward' kiwifruit. Botryosphaeria dothidea rots seem to be sporadic in nature, with severe outbreaks occurring on 'Hayward' in and on 'Hort16A' in The outbreak on 'Hort16A' caused serious losses before harvest and during the early coolstorage period. However, this disease has not been a problem in recent years and the reasons for the outbreak are not fully understood. If infection occurs, it is likely that the source of B. dothidea inoculum is woody tissue of shelterbelt species and kiwifruit prunings (Pennycook 1985). Other Botryosphaeria species isolated on rare occasions from fruit rots in storage include B. parva and B. lutea. B. stevensii has been associated with a distal end deformity of fruit on the vine. Botrytis cinerea Pers. After 10 days growing on PDA, B. cinerea appears grey-white with a profuse covering of silver-grey conidia produced on tall conidiophores. The conidiophores become black with age. The underside of the plate appears light grey and as cultures age black sclerotia form on the colony surface. Further description of the fungus is presented by Ellis (1971). On 'Hort16A', B. cinerea is generally isolated from stem end (Fig. 2A) and wound rots (Fig. 2B). Symptoms appear watery although the affected area

6 Manning et al. Fungi associated with 'Hort16A' rots in NZ 319 Fig. 2 Botrytis cinerea on Actinidia chinensis var. chinensis fruit. A, Stem end rot with mycelium emerging from the picking wound. B, Wound rot. is firm. Rots are generally symmetrical with a distinct margin. As the rot progresses, greyish, fluffy mycelium may appear from the wound site. Symptoms in 'Hayward' are similar (Pennycook 1985). An overview of this disease is provided by Michailides & Elmer (2000). Cryptosporiopsis sp. Colonies grow concentrically on PDA and are flat, shiny, ranging from light to red orange. The underside of the plate is a similar colour. This description of colony growth is similar to that provided in Hawthorne et al. (1982) for Cryptosporiopsis sp. recovered from 'Hayward' kiwifruit tissue. The conidial characteristics are also described. Cryptosporiopsis sp. symptoms on 'Hort16A' (Fig. 3A,B) are small (3-6 mm in diam.), distinctive, often solitary, sunken pits on the fruit surface. Peeling back the skin reveals a shallow layer of dry, yellow tissue that is quite characteristic for this disease. This symptom has been commonly designated as fungal pitting. These symptoms are identical to those described on 'Hayward' by Pennycook (1986) and Manning & Beever (1992). Our experience indicates that the incidence of Cryptosporiopsis sp. pitting in 'Hort16A' is increased by commercial controlled atmosphere storage. This is also the situation in 'Hayward' (Manning & Lallu 1997). Cylindrocarpon cf. candidum (Link) Wollenw. On PDA plates, C. cf. candidum colonies appear orange with a dense upper layer of aerial white mycelium. The underside of the plate is bright orange with a white margin of growing mycelium. Conidiogenous cells are x 3-5 (Am cylindric,

7 320 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31 Fig. 3 Cryptosporiopsis sp. fungal pitting on Actinidia chinensis var. chinensis fruit. A, Characteristic fungal pitting symptom. B, Pale yellow dehisced tissue beneath the skin. wall thickened at the single, apical conidiogenous locus, held on irregular, several-branched conidiophores. Microconidia 6-10 x (Am, oblong-elliptic, ends rounded, 0-septate, hyaline. Macroconidia (19-)50-70 x 5-6 Am, (1-)3-6 septate, slightly curved, broadly rounded both ends, hyaline. Although the isolates from kiwifruit match C. candidum microscopically, the appearance in culture differs. C. candidum cultures were described by Booth (1996) as " yellowish brown from below, becoming darker and finally chocolate brown". C. candidum is the conidial state of Neonectria coccinea (Pers.) Rossman & Samuels. Cylindrocarpon cf. candidum is associated with a distinctive stem end rot occurring in 'Hort16A' after c. 16 weeks in coolstorage. Lesions are characterised by collapsed tissue centred on the stem end with conspicuous white, aerial mycelium erupting from the picking wound (Fig. 4). This rot is not known from 'Hayward'. Diaporthe spp. No attempt has been made to distinguish taxa amongst the Diaporthe species isolated. In most instances, only the Phomopsis conidial state has been observed. It is likely that a range of taxa similar to those reported by Hawthorne et al. (1982) for A. deliciosa will also occur on A. chinensis. Diaporthe spp. colony appearance on PDA varies from white to brown with a covering of aerial, white mycelium. Pycnidia at the centre of the colonies exude masses of white-salmon pink spores. Pycnidial fruiting bodies solitary, partly immersed in agar, globose, mm diam., with narrow ostiolar neck up to 0.5 mm long. Conidiogenous cells x (Am, narrow-cylindric, wall

8 Manning et al. Fungi associated with 'Hort16A' rots in NZ 321 Fig. 4 Cylindrocarpon cf. candidum stem end rot with conspicuous white mycelium on Actinidia chinensis var. chinensis fruit. slightly thickened at apical conidiogenous locus, several held on short conidiophores branched near the base. Conidia x Am, oblong-elliptic, tapering gradually to both narrowly-rounded ends, widest point towards apical end of conidium, 0-septate, hyaline. Diaporthe spp. are the most commonly isolated fungi associated with storage rots of 'Hort16A', and are most strongly associated with distal end and side rots. Distal end rots are characterised by their location. Tissue beneath the beak softens and as the rot progresses, it spreads through the fruit advancing toward the stem end. The appearance of Diaporthe spp. side rots is variable and isolation from the affected tissue is required to distinguish the cause from that of other rots (Fig. 5). Diaporthe spp. are ubiquitous within orchards and on kiwifruit tissue in general, for example necrotic leaves and prunings (M. A. Manning unpubl. data). Phoma exigua Desm. Phoma exigua colonies on PDA are black with or without white aerial mycelial covering and with irregular margins. The underside of the plate is either black with a white growing margin or greenish-grey with occasional patches of black and a white growing margin. Dorenbosch (1970) provides a full description of this fungus. Phoma exigua is associated with all 'Hort16A' rot types and is quite frequently recovered from wound rots. Lesions are characteristically dark brown and firm (Fig. 6A). Diseased tissue beneath the skin is a Fig. 5 Diaporthe sp. side rot on Actinidia chinensis var. chinensis fruit. similar colour and is clearly defined from the surrounding healthy tissue (Fig. 6B). Phoma spp. fructifications are frequently observed on necrotic leaf tissue collected from 'Hort16A' orchards and incubated in a humid environment (M. A. Manning unpubl. data). In 'Hayward' orchards, Hawthorne et al. (1982) isolated P. exigua, P. macrostoma, and an unidentified Phoma sp. from fruit and leaves. Other less frequently isolated fungal species Colletotrichum acutatum J.H.Simmonds On PDA, colonies appear pink to grey, often with a dense grey aerial layer. The underside of the plate also varies from pink to grey. Cylindrical conidia, pointed to the ends are born in the aerial mycelium.

9 322 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31 Fig. 6 Phoma exigua wound rot on Actinidia chinensis var. chinensis fruit. A, Wound rot. B, Wound rot peeled to expose affected tissue beneath skin. Colletotrichum acutatum has been isolated at low frequency from most rot types of 'Hort16A'. In 'Hayward', C. acutatum rots occur as fruit are ripening rather than during coolstorage (Brook 1992). This is also the case in 'Hort16A'. Fusarium spp. Fusarium spp. are most commonly isolated from stem end (4.4%) and wound (3.4%) rots although they are also isolated infrequently from most 'Hort16A' rot types. Typical stem end symptoms are similar to stem end rots caused by Cylindrocarpon cf. candidum in that white mycelium is often conspicuous at the point of detachment of the fruit from the peduncle. Mucor piriformis A. Fisch. Mucor piriformis rots occur infrequently on 'Hort16A' in coolstorage. This fungus produces typical pin-mould symptoms Fig. 7 Sclerotinia sclerotiorum scarring on young fruit of Actinidia chinensis var. chinensis attached to the vine.

10 Manning et al. Fungi associated with 'Hort16A' rots in NZ 323 with profuse conidiophores emerging from the affected area. Affected tissue is soft, almost liquefied and tissue fragments often adhere to the skin as it is peeled back. Pezicula spp. There is a range ofpezicula spp. isolated from 'Hort16A' fruit; two species are described here. Typically, colonies on PDA range from white to olivaceous with a white aerial mycelial covering. The undersides of plates range from cream to chestnut. The descriptions below are based on morphological comparison with Verkeley (1999) as well as ITS sequences (P. R. Johnston unpubl. data). Pezicula sp. nov. 1 (sensu Abeln et al. 2000) (ICMP , ITS sequence lodged in GenBank AY344802) conidiomata are superficial on agar surface, more or less globose, dark-walled, irregularly splitting to reveal one or more cupulate acervuli, each of which is covered by a pale creamy-yellow conidial mass. Conidiogenous cells x 4-5 (Am, cylindric, acrogenous, indistinct periclinal thickening, occasionally proliferating percurrently, held on loosely and irregularly branched conidiophores. Conidia x 9-12 (Am, oblong, apex broadly rounded, protruding truncate scar at base, 0-septate, hyaline. The teleomorph of this species is unknown. Pezicula cinnamomea (ICMP 14404, ITS sequence lodged in GenBank AY344803) teleomorph form on agar. Apothecia developing on surface of agar, small, more or less sessile, both hymenium and receptacle pale yellow-orange. Asci x (Am, broad-clavate, tapering to narrow base, tapering to rounded apex, wall thickened at apex, nonamyloid, 8-spored (rarely with variable number of spores aborting). Ascospores x (Am, oblong-elliptic, tapering slightly to broadly rounded ends, slightly curved, hyaline, 0(-3) septate. Pezicula spp. are isolated from all types of 'Hort16A' rot to some extent. Symptoms are indistinct and isolations from the affected tissue are required to identify the causal fungus. Phialophora sp. Phialophora sp. mycelium on PDA has a flat growth habit and ranges in colour from green-grey to dark grey with a similar appearance on the underside of plates. Conidia (3.2) 5-8 (-11) x (Am, oblong, straight (larger spores often slightly and irregularly curved and slightly constricted near centre), apex broadly rounded, tapering to small truncate base, hyaline, 0-septate. Phialophora sp. was isolated from c. 1% of fungal pits and side rots and infrequently from other 'Hort16A' rot types. This genus has been reported as the cause of pitting in 'Hayward' kiwifruit in Italy (Testoni et al. 1997). Sclerotinia sclerotiorum (Lib.) de Bary Sclerotinia sclerotiorum colonies on PDA are white with a faint tan tinge and a light layer of white aerial mycelium. Black sclerotia form at the plate margin and no spores are produced in culture. For a full description of this fungus refer to Kohn (1979). Sclerotinia sclerotiorum is the main fungus regularly affecting 'Hort16A' fruit while on the vine. This species has been isolated from fruit rots soon after flowering, although the most detrimental effect of S. sclerotiorum infection is fruit scarring (Fig. 7) which leads to fruit rejection at harvest. Pennycook (1985) describes the symptoms and etiology of S. sclerotiorum rot in detail for 'Hayward' kiwifruit on which it is currently of more concern than in 'Hort16A'. The saprophytic fungi, Alternaria sp., Cladosporium sp., Pencillium spp., Epicoccum sp., and Pestalotiopsis sp., are occasionally isolated from a range of 'Hort16A' rots. CONCLUSIONS Currently, Diaporthe spp. and Cryptosporiopsis sp. are the major rot causing organisms of 'Hort16A'. Diaporthe spp. are most strongly associated with distal end rots whereas Cryptosporiopsis sp. is recovered most frequently from fungal pits. These fungi also account for the majority of side and wound rots. Side and distal end rots and fungal pitting are the most prevalent rot types in 'Hort16A'. Stem end rots are relatively uncommon and are mainly associated with Cylindrocarpon cf. candidum. Botryosphaeria dothidea tends to be associated with side rots in low numbers overall, but is of concern to industry as it periodically causes large fruit losses preharvest and early in coolstorage (before 12 weeks). Inoculum of many of the other fungi discussed is common on orchard tissue and the rots may increase in importance to industry over time. Overall, 'Hort16A' and 'Hayward' are affected by a similar suite of rot-causing fungi which tend to produce similar symptoms on both cultivars. For example, B. dothidea causes sporadic epidemics of preharvest disease with identical symptoms in both kiwifruit species. Cryptosporiopsis sp. pits and Botrytis cinerea stem end rots also produce the same symptoms on 'Hayward' and 'Hort16A' kiwifruit. Although similar fungi infect both 'Hort16A' and 'Hayward', the incidence of storage disease varies.

11 324 New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31 The 'Hayward' crop tends to be affected by B. cinerea stem end rots as early as 4 weeks in coolstorage (Pennycook 1985). In contrast, 'Hort16A' is relatively unaffected by rots before 12 weeks because of a relatively low incidence of B. cinerea infections. It is the long-term storage of 'Hort16A' that is limited by rots, predominantly caused by Diaporthe spp. and Cryptosporiopsis sp. These two fungi occur infrequently in 'Hayward' (Brook 1990). ACKNOWLEDGMENTS We gratefully acknowledge Shaun Pennycook for assistance with descriptions of fungi; Kerry Everett and Warwick Henshall for comments on the manuscript; and Anne Gunson for statistical analysis. Funding for the preparation of this manuscript was provided by the New Zealand Foundation for Research, Science and Technology C06X0006. Results were derived from work undertaken for ZESPRI Innovation Company Ltd. REFERENCES Abeln, E. C. A; Pagter, M. A. de; Verkley, G. J. M. 2000: Phylogeny of Pezicula, Dermea and Neofabraea inferred from partial sequences of the nuclear ribosomal RNA gene cluster. Mycologia 92: Booth, C. 1966: The genus Cylindrocarpon. Mycological Papers p. Brook, P. J. 1992: Botrytis stem-end rot and other storage diseases of kiwifruit a review. Second International Symposium on Kiwifruit. Palmerston North, New Zealand February Acta Horticulturae 297: Brook, P. J. 1990: Diseases of kiwifruit. In: Warrington, I. J.; Weston, G. C. ed. Kiwifruit: science and management. Auckland, Ray Richards. Pp Brooks, C.; Cooley, J. S. 1917: Temperature relations of apple-rot fungi. Journal of Agricultural Research 8: Dorenbosch, M. M. J. 1970: Key to nine ubiquitous soilborne Phoma-like fungi. Persoonia 6: Ellis, M. B. 1971: Dematiaceous Hyphonomycetes. Kew, Commonwealth Mycological Institute. 608 p. Hawthorne, B. T.; Rees-George, J.; Samuels, G. J. 1982: Fungi associated with leaf spots and postharvest fruit rots of kiwifruit (Actinidia chinensis) in New Zealand. New Zealand Journal of Botany 20: Kohn, L. M. 1979: A monographic revision of the genus Sclerotinia. Mycotaxon 9: Manning, M. A.; Beever, D. J. 1992: An update on storage pitting research. NZ Kiwifruit February: 5-7. Manning, M. A.; Lallu, N. 1997: Fungal diseases of kiwifruit stored in controlled atmosphere conditions in New Zealand. Proceedings of the Third International Symposium on Kiwifruit. Thessaloniki, Greece September Acta Horticulturae 444: Michailides, T. J.; Elmer, P. A. G. 2000: Botrytis gray mold of kiwifruit caused by Botrytis cinerea in the United States and New Zealand. Plant Disease 84: Pennycook, S. R. 1986: What makes a kiwifruit a rotten kiwifruit. NZ Kiwifruit April: 17. Pennycook, S. R. 1985: Fungal fruit rots of Actinidia deliciosa (kiwifruit). New Zealand Journal of Experimental Agriculture 13: Pennycook, S. R.; Samuels, G. J. 1985: Botryosphaeria and Fusicoccum species associated with ripe fruit rot of Actinidia deliciosa (kiwifruit) in New Zealand. Mycotaxon 24: Testoni, A.; Grassi, B.; Quaroni, S.; Saracchi, M.; Sardi, P. 1997: Pitting on kiwifruit in storage caused by Phialophora sp. Proceedings of the Third International Symposium on Kiwifruit. Thessaloniki, Greece September Acta Horticulturae 444: Verkley, G. J. M. 1999: The monograph of the genus Pezicula and its anamorphs. Studies in Mycology p.