A survey was carried out between July and September 2000 in l'Ovineyards, (8 in Malta and 2 in Goro) to investigate which fungal diseases were present. Samples, which included leaves, berries and stems infected by the fungi, came from both traditional and modem vineyard cultivation. Pathogenic fungi identified included 26 different fungi belonging to 21 genera; 21 taxa were reported on Vitis vinifera L. for the . first time in the Maltese Islands. It was observed that the intensity of diseases was much more pronounced in the traditional rather than in the modem method of vine-training.peer-reviewe

Tabone, Matthew

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The Central Mediterranean Naturalist 3(4): 211-214 Malta: December 2002 A SURVEY OF FUNGAL DISEASES ASSOCIATED WITH VITIS VINIFERA L. IN THE MALTESE ISLANDS Matthew Tabone! ABSTRACT A survey was carried out between July and September 2000 in l'Ovineyards, (8 in Malta and 2 in Goro) to investigate which fungal diseases were present. Samples, which included leaves, berries and stems infected by the fungi, came from both traditional and modem vineyard cultivation. Pathogenic fungi identified included 26 different fungi belonging to 21 genera; 21 taxa were reported on Vitis vinifera L. for the . first time in the Maltese Islands. It was observed that the intensity of diseases was much more pronounced in the traditional rather than in the modem method of vine-training. INTRODUCTION A survey was carried .out between July and September 2000 in 10 vineyards, 8 in Malta and 2 in Gozo to investigate fungal diseases of vines. Table 1 shows the location of the fields sampled. METHODS Samples (i.e. leaves, berries or stems) were taken from vineyards where traditional practices were followed as well as vineyards using modem practices. Field samples infected by fungi were quickly transferred to th~ Plant Health Laboratory at Marsa and stored in a cooler so as to preserve them. . In the laboratory, the samples, together with instruments and working bench, were first sterilised with appropriate disinfecting solutions (Brookes, 2001). Infected plant organs were carefully examined under a stereomicroscope for the presence of any fruiting bodies and fungal hyphae and thfm sectioned and cultured in agar- to allow the fungus to develop. Culture media such as water agar, potato dextrose agar and Czapek dox were used according to whether the need was for a general or specialised medium. The prepared media were sterilised in an autoclave. They were then left to cool to a temperature of 45°C. The prepared agar suspension was cautiously poured in petri Table 1. Sampling data , Sample Number Sampling Locality Sampling Date Type of Cultivation I Marsaxlokk, Malta 17.07.2000 Modem 2 Wardlja, Malta 20.07.2000 Modem 3 Bingemma, Malta 24.07.2000 Traditional 4 Buskett, Malta 25.07.2000 Traditional 5 Fomm ir-Rih, Malta 30.07.2000 Traditional 6 Ta' Qat1, Malta 01.08.2000 Modern 7 Tas-Silg, Delimara, Malta 20.08.2000 Traditional 8 Tas-Salib, Rabat, Malta 20.08.2000 Traditional 9 San Lawrenz, Goro - 01.09.2000 Traditional 10 xa.ghni, Gozo 01.09.2000- Traditional· I Department ofPl~tHealth, Plant Quarantine Section, Ta' Qal!., Malta. 211 dishes in. equal proportions to a thickness of5 mm. They ORDER: Erysipbales were left to solidify in a laminar flow cupboard and annotated appropriately. Infected plant tissues were then Family: Erysipbaceae placed on the agar and after some days the fungi were examined under both a stereomicroscope and a high power Uncinula necator (Schwein.) Burrill 1851 compound microscope. Fungal characteristics were noted and apprepriate keys, used for identification (see fungal ORDER: Microascales key references). Family: Microascaceae RESULTS Petriella sp. * The study produced 26 different taxa in 21 genera. The 21 fungi marked with an asterisk were recorded on Vitis ORDER: Sordariales vinifera L. for the first time in the Maltese Islands. The percentage composition of genera found was as follows: Family: Chaetomiaceae Obligate parasites: 10% (2); Facultative parasites: 29% (6) and Saprophytes: 61% (13) (Tabone, 2001). The following Cifaetomium sp. * is a list of the fungi recorded: Family: Ceratostomaceae FUNGI IMPERFECTI Persiciospora sp. * FORM ORDER: MELANCONIALES Order: Peronosporales Gloeosporium sp. [Two species of Gloeosporium were recorded from vine by Borg (Borg, 1922)] Family: Peronosporaceae FORM ORDER: MONILIALES Family: Dematiaceae Acremonil-lm sp. * Alternaria alternata (Fr.) Keissler, * Alternaria tenuissima (Kunze ex Pers.) Wiltshire, * Aspergillus candidus Link. * Aspergillus jlavipes (Bainier & Sartory) * Aspergillus nidulans (Reinhard Fischer)* Aspergillus niger van Tiegh:, * Aspergillus versicolor (Vuillemin) Tiraboschi * Cladosporium sp. [Two species of Cladosporium were recorded from vine by Borg (Borg, 1922)] Helminthosporium sp .. * Memnoniella sp. * Pseudobotrytis sp. * Stachobotrytis sp. * Stemphylium sp. * Ulocladium sp. * Family: Moniliaceae Botrytis cineria Micheli ex Pers. (1794) Geotrichum sp. * Monilia sp. * FUNGI PERFECTI ORDER: DOTHIDEALES Family: Didymospbaeriaceae Didymosphaeria igniaria Booth, * Plasmopara viticola J. Schrot. (1886) Order: Mucorales Family: Mucoraceae Mucor sp. * Plasmopara viticola and Oidium spp. [oidial state of Uncinula necator (Schwein.) Burrill] were previously recorded on Vitis vinifera L. by Wheeler, B.E.J., (1957). The genus Botrytis was previously recorded by Borg (1922), Sommier & Caruana Gatto (1915) and Brooks, F. E. (2001). The ·two genera Cladosporium and G1oeosporium are mentioned by Borg (Borg, 1922) and are also mentioned in the fungal section of the Red Data Book (Lanfranco, 1989), which was based on Sommier & Caruana Gatto (1915). Note: The Saccardo System was chosen for the classification of Imperfect FungLThe primary basis of this system is the morphology of the sporulating structures as well as the morphology and pigmentation of conidia and conidiophores. However for the two largest families i.e. Moniliaceae and Dematiaceae, the Hughes-Tubaki-Barron System of classification was used. As for Ascomycetes and Oomycetes, the nomenclature. follows Hawksworth, D.L. et ai, 1995. DISCUSSION The most common obligate fungi were Powdery-mildew, Vncinula necator (Schwein.) Burrill (1851); (6.5%), Downy mildew, Plasmopara viticola J. Schrot. (1886), 212 (12%) and grey mould, Botrytis cineria Micheli ex Pers. flower parts that remain in the cluster (Flaherty, 1992). (1794) (23%) (Tabone, 2001). An 'explanation for the high occurrence. of the latter could be due to the ability of this The traditional local grapevine varieties like Girghentina fungus to live as both parasite and saprophyte according to and Gellewza were found in the fields of small-scale or part-prevalent environmental conditions (Vella, 1991). It was time growers whereas foreign varieties were found in the sampled mainly from the berries, although leaves and stems vineyards of commercial growers. It has been observed that were also affected. In the berries various saprophytic fungi the intensity of diseases was much more pronounced in the were present together with B. cinerea, including several traditional rather than in the modem way of training the facultatively parm;itic fungi. vines. The reason is probably that in the traditional bush form wind currents are much reduced and the penetratio~ of Some of the more important facultatively parasitic fungi solar radiation to the inner leaves and berries is also that were found in this study included Alternaria, reduced, thus increasing humidity which promotes the Cladosporium, and Stemphylium. Alternaria was very growth of fungi. . Conversely in the modem, more open common in many of the samples. and this could be due to system, the vines have good air circulation which reduces its dual feeding behaviour i.e. as a primary and secondary the relative. humidity in the vines. Another reason could be invader (Goheen, & Person, ,1994). Cladosporium, like that when using the traditional method, weed removal is Alternaria, is also a parasite but can also be a saprophyte. difficult with the result that any diseased weeds present Only a few specimens of Cladosporium were present in the could infect the vines. Moreover an open canopy not only samples, possibly meaning that either the optimum maintains a microclimate less favourable for disease conditions for this fungus were absent or that it had severe development but also allows for better penetration of competition from 'other fungi such as Alternaria (Tabone, fungicides used to prevent or control the disea,ses (Tabone, 2001). An important facultative parasitic fungus was 2001). Stemphylium which was found in 47% of all samples. It was -:-:--::--:::-:::::-=---=--=---=-=------------noticed in the petri dish cultures that the populations of ACKNOWLEDGEMENTS Alternaria and Stemphylium were inversely proportional . possibly due to competition between the two fungi (Tabone, I gratefully ac~owledge the adVIce ~d suggestio~s made 200 I). There seems to be an association between Alternaria by. Mr .. Antome Vella at the InstItute of Agn.culture, and other species and Stemphylium according also to Smith UmversIty of Malta. I also thank Mr. Carmel FarrugIa at the et al (1988). . ' Dep~ent of P~ant Health f~r m~ing valuable suggestIOns regardmg the expenmentatIOn and the Saprophytes "included Aspergillus, Acremonium and Stachobotrytis amongst others. A relatively common disease was Grey Rot caused by the parasitic fungus Botrytis cinerea. Rot caused by Helminthosporium spp. alone is very similar to that caused by Cladosporium herbarum. These fungi, Botrytis and Helminthosporium, grow under humid conditions and sporulate on cast-off REFERENCES identification of fungi. Moreover I thank Dr. D. Mifsud and Mr. E. Lanfranco for having supplied me with important relevant literature and help in editing this paper. I thank particularly the field owners who allowed me to take samples without which this study would not have been possible. (Accepted iOth December 2002) Brooks, F. (i001) Plant Disease Manualfor Semi-arid & Mediterranean-type Climate, Malta University Press. Flaherty, D.L. et al (1992) Grape Pest Management. Division of Agriculture and Natural Resources, University of California Goheen, A.C. & Pearson, R.c. (1994) Compendium of Grape Diseases, APS Press. Lanfranco, E. (1989): The flora. In Schembri, P.J. and Sultana, 1. (Eds.): Red Data Book for the Maltese islands. Ministry of Education, Malta. Smith I.M., Dunez J., Phillips D.H., Lelliot R.A. and Archer, S. A. (Eds.) (1988) European Handbook of Plant Diseases, Blackwell Scientific Publications. Tabone, M. (2001) A survey of fungal diseases associated with Vitis. Unpublished M.Sc. dissertation; Institute of Agriculture, University of Malta. Vella, A. (1991) Mard u Parassiti tad-Dielja, Dipartiment ta' I-Agrikoltura u Sajd. Wheeler, B.E.J. (1957) A Plant disease survey of Malta. Unpublished document. Commonwealth Mycological mstitute. Fungal Keys consulted: Barnett, H.L. & Hunter, B.B. (1999) Illustrated Genera of Imperfect Fungi APS Press. Caine, T. (2000) Mycological Techniques In: International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International, Mycological Institute, Kew, Surrey, UK. David, J. (2000) Alternaria, Mycosphaerella, Cladosporium, Cercospora and related genera In: International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International, Mycological Institute, Kew, Surrey, UK. 213 Ellis, M.B. (1993) Dematiaceous Hyphomycetes, CAB International, International Mycological Institute. Ellis, M.B. (1993) More Dematiaceous Hyphomycetes, CAB International, International Mycological Institute. Hawksworth, D.L. et al (1995). Ainsworth and Bisby's Dictionary o/the Fungi. International Mycological Institute, CAB International. . Kinsey, G. (2000) Introduction to Ascomycetes in International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International Mycological Institute, Kew, Surrey, UK. Kinsey, G. (2000) Powdery Mildews in International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International Mycological Institute, Kew, Surrey, UK. Lawrence, z. (2000) Aspergillus and Penicillium in International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International Mycological Institute, Kew, Surrey; UK. . Ritchie, B. (2000) Plant Pathology Techniques and Assocfated diseases in International Course on the Identification of Fungi of Agricultural and Environmental Significance. CAB International Mycological Institute, Kew, Surrey, UK. Stamps, J., Hall, G. & Beakes, G. (2000) Pythium, Downy Mildews and other genera in International Course on the Identification of Fungi of Agricultural and Environmental· Significance. CAB International Mycological Institute, Kew, Surrey, UK. 214 

A survey of fungal diseases associated with Vitis vinifera L. in the Maltese Islands

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A survey of fungal diseases associated with Vitis vinifera L. in the Maltese Islands

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