Begins with careful cultural and sanitation practices. Prune out witch's brooms and destroy with fire then sterilize pruning tools. Early spring applications of Cleary prior to flush are beneficial. Spray anti-bacterial products. Most are physiologically harmless to the tree.
Control is very difficult to attain and is often unnecessary.
Otherwise, prune and destroy clippings. Dark gray in color. Mold begins from inside the plant and moves outward. Insect on under side of leaf. During early spring, about the time the leaves reach full size, light green areas appear on them, with the affected area raised on the upper and depressed on the lower leaf surface.