Tiny black specks in rings are visible in the spots and blotches. Severe infections cause the trees to loose their leaves prematurely. Trees of low vigor, that are repeatedly defoliated, may die. Small trees defoliated several years in a row may need spraying. Apply Bordeaux mix or another copper fungicide, mancozeb or thiophanate-methyl according to the instructions on the labels.
Complete coverage is necessary for control.
The symptoms consist of a white, powdery growth on both leaf surfaces. The foliage may be malformed, dropping prematurely or drying out and shriveling. Sometimes the grayish-white fungal growth changes to tan and then brown with age. Thiophanate-methyl may be used to control powdery mildew in severe cases. Follow the directions on the label.