I have the same problem. I saved a wild peach tree from a drain - it has grown beautifully, full blossom every year - but every year all the peaches are rotten inside. Have been told need to spray herbicide before and after flowering and when fruit very small. Someone else has said best to remove tree and burn, so as not to affect nectarine and apricot trees nearby. Seems a shame. Hopefully someone can recommend an ecological solution!
