A few of nearly all of the leaves on a tree may fall, depending upon the severity of the attack. As the growing season advances, the upper surface of diseased leaves gray and develops a powdery appearance. Dry weather soon withers the leaves causing them to fall early. However, cool weather delays defoliation. Young infected peach fruits become distorted and seldom remain on the tree very long.
Infected fruits show irregular, swollen, colored areas on their surfaces.
These areas are usually wrinkled, without the normal peach fuzz, and look like they have been polished. Cause Peach leaf curl is caused by the fungus Taphrina deformans . Spores of the fungus are produced on the surface of diseased leaves in midsummer and give the leaf the powdery appearance previously described. These spores are spread to all parts of the tree by winds and rains, becoming lodged under bud scales and rough bark, and here they remain throughout the summer and winter months. In the spring, when the young peach buds begin to swell, germinating spores of the fungus penetrate the young leaves, causing leaf curl infection.