Answer: What you describe sounds like a fungal disease but without seeing the tree, I can't say for certain. Apple trees are susceptible to fungal diseases and are generally put on a spray schedule in the early spring to help avoid the problems. Lime/sulfur applications can be made just as the tree is beginning to blossom and leaf out. Your cooperative extension office can provide an apple tree spray guide and can also diagnose the problem if you take a sample of the affected leaves to their office. Here's a website to help you determine where your local cooperative extension office is located: http://www.caes.uga.edu/extension/statewide.cfm
Best wishes with your apple tree!
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