My uncle's grapes (concord I think), developed some sort of discolor and some became desiccated over the weekend (June 29 - July 2, it was the hot one if you remember).
Did some research online, and it appears that it was some kind of fungus, although I am unsure which type.
My question is, can you identify the type of ailment from my attached photo, and recommend a remedy?
Some background info: the vines are located in Bridgman, which I believe to be concord, though I am not certain. The symptoms appeared over a weekend, which was particularly hot and humid- a factor with certain fungi from what I read, and roughly half of his current grapes seem to be affected, and the leaves appear to be not as widely affected.
Berrien County Michigan