Define "damage to fruit development." Does that include killing a vine deader than a doornail? Actually, I had problems with some apple and peach trees 30 years ago. I had been using a product called Orchard Spray. I don't remember which company made it. I had been following the directions, but the trees were damaged slightly. The only thing I can think of that I might have done wrong was spraying too often. The spray had an insecticide and a fungicide in it as I recall. But it could have been a neighbor's lawn service using 2, 4, d for broadleaf weed control. 2,4,d is bad about drifting.