Leaf Curl is a fungal disease that overwinters in the crevices of the tree bark and around the buds. One or two well-timed applications for most stone fruits should control the disease. The timing of the fungicide spray varies with differing stone fruit varieties. For apricots, spraying at 90% leaf fall and again as buds show pink is recommended. For peaches and nectarines, spraying is best in late winter prior to bud swell and again when buds start to swell (bud scales start to loosen).
Leaves are curled, change colours and are severely deformed. Leaves finally turn brown, shrivel and drop from the tree. Fruits may drop early, or turn reddish-purple with warty growths on the outer surface.