Is this Fire blight?
My apple tree leaves started turning brown, and falling off, about half the tree is affected now. I had it pruned in the spring, and sprayed for Coddling Moth in the spring. I have my lawn fertilized by a company, but no other plants or trees are affected with this. It gets enough water.
It looks like the leaves on the top of the tree turned brown first, and then it started traveling down the tree. The leaves underneath are still mostly green.