Project number:
US PP 02 2001
Project leader:
Fourie, P H
Institution:
University of Stellenbosch. Department of Plant Pathology.
Project description:
The fungi most commonly isolated from roots of dead and dying nursery grapevines in the Western Cape, according to Marais (1980), were Pythium spp. [P. ultimum Trow, P. aphanidermatum (Edson) Fitzpatrick, P. sylvaticum complex, P. irregular complex and P. rostratum complex] and Phytophthora spp. [P. cinnamomi Rands, P. nicotianea Dastur, P. cryptogea Pethybridge and Lafferty, P. cactorum (Lebert and Cohn) Schroeter and P. megasperma Dreschler]. Other less important pathogens included Rosellinia necatrix (Hart) Berl. and Sclerotium rolfsii Sacc.
Preliminary surveys have shown that due to the fungicide application regimes being followed, the pathogen populations in vineyard soil have changed significantly since the 1980s. The aim of this study was thus to carry out a re-assessment of fungi associated with root diseases of nursery grapevines in the Western Cape. Pathogenicity tests will confirm which of these pathogens isolated pose a threat to nursery grapevines. Further fungicide work (Petri dish trials) will confirm which products can be considered for disease control. In this regard, nurserymen will be able to limit their losses from soil borne diseases, by means of effective disease control measures.
Presentations:
Van Coller, G J, Denman, S, Crous, P W and Fourie, P H. 2003. The effect of downy mildew chemicals on the infection of nursery grapevines by Phytophthora cinnamomi. Paper presented at the 41th Southern African Society for Plant Pathology Congress. 19-22 January, Bloemfontein, South Africa.
Van Coller, G J, Denman, S, Crous, P W and Lambrechts, S C. 2003. A new perspective on soilborne diseases of grapevines in nurseries. Paper presented at the 27th National Congress of the South African Society for Enology and Viticulture. 5-7 November, Somerset West, South Africa.
Fourie, P H and Halleen, F. 2003. Nursery strategies for the management of decline and dieback research progress. Paper presented at the 27th National Congress of the South African Society for Enology and Viticulture Congress. 5-7 November, Somerset West, South Africa.
Fourie, P H and Halleen, F. 2004. Proactive management of grapevine trunk diseases in nurseries: an integrated approach. Paper presented at the 42nd Southern African Society for Plant Pathology Congress. 18 -21 January, South Africa.
Van Coller, G J, Denman, S, Crous, P W and Lambrechts, S C. 2004. Fusarium spp. associated with roots and crowns of nursery grapevines in the Western Cape province. Paper presented at the 42nd Southern African Society for Plant Pathology Congress. 18 -21 January. South Africa.
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