Assessment of bio control potential of Ampelomyces quisqualis against powdery mildew of grapes

Abstract

owdery mildew (Erysiphe necator) is one of the most important biotic constraints in grape (Vitis- vinifera L.) limiting the commercial production of the crop in most of grape growing regions in India. Disease management with fungicides is a common practice but fungicide resistance and environmental pollution issues have brought to the fore the extensive use of biocontrol agents. Ampelomycesquisqualis is a naturally occurring preventive biological fungicide that hyper-parasitizes powdery mildew pathogen. Evaluating the efficacy of Ampelomycesquisqualis 2% WP formulation against powdery mildew of Tas-A-Ganesh variety was done. Five sprays of Ampelomycesquisqualis 2.0% WP @ 6 g/L, 8 g/L and 10 g/L were given at 10 days interval for disease management. Among all treatments, foliar spray application of Ampelomyces quisqualis 2.0% WP @ 10 g/L manifested maximum efficacy in controlling the disease on leaves and bunches with mean PDC of 24.63 and 22.48 respectively. Untreated control manifested mean PDI of 40.20 and 39.78 on leaves and bunches. A significant increase of in marketable yield was also observed. The results of this study suggest that the Ampelomyces quisqualis 2.0% WP 10 g/L have potential to be used for the management of grape powdery mildew.