Apple tree problem
I have numerous apple trees that are becoming covered with what looks like ashes. If you kind of rub at it it does come off but it is covering all off the tree. It also spreads over the buds. Seems to almost suffocate the tree branches until they dry out and become brittle and break. It prevents any good fruit from developing and is spreading threw several trees. I try to be diligent with my spraying and nothing is helping. I need suggestions so we do not lose our entire orchard.
Beaver County Pennsylvania
Based on the description and pics you provided your orchard may be suffering from powdery mildew of apple. The links below provide some additional insight about the origin, symptoms, and treatment for powdery mildew on apple.
After reviewing these links, if you are still in doubt, it would be best to take a sample to your local extension office for on-site inspection and recommendations.