For the last several years, I have been unable to get apples on the three dwarf apple trees we have growing in the back. At first I assumed the issue was Plum Cuculia and attempted to stop it by spraying, wrapping the trunk, and using nematodes. Being that this has not helped in the slightest, I was wondering if anyone could diagnose the problem. The trees are on Long Island and similar issues exist on a cherry tree nearby and some grape vines. The flowers get pollinated and form fruit, but early on they get spots on the apples and the leaves get discolored (see the attached photo). The apples then become misshapen and eventually fall off in early August. I was wondering if maybe the soil is devoid of nutrients or if there is anything else I can try aside from the above. I never see insects getting into the fruit so I am starting to doubt its a bug.

Thanks!