Answer: Unfortunately, based on the information in your description, I am not able to tell you what is happening to your trees. Black spots on peach foliage is not a symtom of the more common peach diseases, but it might be sooty mold growing on honeydew from insects feeding on the tree. When a newly planted tree defoliates, it is a sign of severe stress, possible related to incorrect watering. I would suggest you consult with your local Penn State cooperative extension for help in diagnosing the problem(s). If a chemical control is needed, they will have the most up to date information on what to use and how/when is best to use it for maximum results. Also, they will be able to help you plan out a regular spray control program for your fruit trees. In the meantime, you may find the following publication helpful. It outlines care for both peaches and cherries.
Good luck with your new trees!
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