Answer: I can't tell from your description whether you are dealing with a fungal disease or your tree has a population of mealy bugs or cottony scale insects. The treatments are quite different for each of these possibilities. I think the best approach is to remove one of the affected branches, or at least the white mossy looking stuff and take it to your local cooperative extension office or well staffed nursery for help. Once the specimen has been examined by professionals you'll have your answer - and helpful folks there can suggest a control remedy, depending upon the type of tree you are growing. Best wishes with your tree!
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