Answer: Flowering cherries are susceptible to many problems, including cherry virus diseases, canker, twig blight, root rot, powdery mildew, bacterial and fungal leaf spots, borers, aphids, tent caterpillar, and scale. Bark is thin and easily damaged by mowers and string trimmers. You can reduce chances of disease and insects by keeping trees healthy with irrigation in extended drought and regular fertilizer applications.
With that said, I can only suggest you take a sample of the affected leaves and branches to your local Cooperative Extension office for positive diagnosis. If it is a disease they will be able to identify it through microscopic examination of the plant parts. They will also be able to suggest control measures.
Best wishes with your cherry tree.
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