Answer: Grapes are subject to many fungal infections and damp weather certainly contributes to the problem, as does improper pruning or thinning. Most gardeners find that they need to follow a regular preventive spray routine in order to produce quality grapes. The recommendations would depend on the variety you are growing, its disease resistances and the local incidence of problems, as well as the weather each year. You might want to contact your county extension (788-1338) for localized recommendations for raising grapes in your area. In the meantime, remove and destroy any infected fruit and foliage to try to minimize the reinfection and be careful not to handle the plants when they are wet. This fall and winter do a thorough clean up of the area including removal and destroying all prunings from the vines.
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