New perspectives for the use of Ampelomyces-based biofungicides for effective control of powdery mildew on grapevine

Powdery mildew (PM) is one of the most widespread diseases of grapevine across Europe, and its control requires intensive fungicide sprays. During a 3-year study (2007-09) carried out in Northern Italy, the efficacy of late-season applications of the hyperparasitic fungus Ampelomyces quisqualis isolate M-10 (formulated product: AQ10\uae WG), a sustainable alternative to chemical fungicides, in reducing PM inoculum and thus disease pressure the following season was evaluated. AQ10 proved to be effective in stopping the production of new chasmothecia and reducing the number of mature ascocarps in potted grapevine plants, leading to reducing the PM severity on both leaves and bunches in the vineyard the following season. Late-season applications of AQ10 showed a mean efficacy of 40% (1 application) to 64% (2 applications) in reducing disease severity on bunches the following sprin