Reddish Marks on Leaves of Fruit Trees
Peaches, plum, and grapevines get these reddish, maroon circles that get bigger and then make holes in the leaves. The leaves then turn yellow and fall off the trees. I see no insects of any kind. I use dormant oil in the spring then start a regular program of Reteone and Bordeaux mix as per instructions for each. The trouble seems to start in early July. We have had a lot of rain, so my spraying program has been off some. This has happened to me in the past. What can I do to keep my trees and vines healthy? Right now about 70% of the foliage is gone. My pear and apple trees look good.
It sounds like shot hole disease. This article has the information you need: https://www.gardeningknowhow.com/plant-problems/disease/shot-hole-disease-fungus.htm