"Cedar apple rust (CAR) is an important fungal disease of apple in North America east of the Rocky Mountains. It can defoliate trees and blemish fruit making them unmarketable. The CAR fungus requires two hosts, apple and eastern red cedar (Juniperus virginiana L.), to complete its life cycle."
Google it for more details but I think you might be OK with plumb and peach, I don't have any of those. Its really bad on my apple verities. Come to think it may be well apples. I'm going to check now haha
