There are a variety of afflictions that can be found on tree fruits, from fungal rots to bacterial infections. As disconcerting as it can be to see your tree beset by these, there is almost always a solution for what ails you. When selecting the variety of fruit that you want, disease resistance is something to consider. If, for instance, your neighbors have towering cedar trees on their property, finding a variety of apple with some resistance to cedar apple rust may be a good idea. You can find some very helpful information on the identification and management of fruit diseases at the website for the Penn State Extension program and, of course, there is a wealth of other information in our Resources and Links page.