Peach leaf curl, caused by the fungus Taphrina deformans, is a common springtime disease of peaches. The disease is easy to recognize. Infected leaves are thickened and puckered and often turn a reddish color. The symptoms may be limited to small areas of the leaf or may involve the entire leaf. Infected leaves turn gray and eventually wither and fall from the tree. The disease may also occur on the fruit, blossoms, and young twigs. Infected shoots appear stunted, swollen, and chlorotic. Diseased fruits exhibit raised, wrinkled areas and often fall prematurely.
Infection occurs during the spring from bud swell to bud opening. Spores of the fungus, which overwinter on bark and bud scales, wash onto the young leaf tissue in wet weather and initiate infections. Leaf curl is most severe when weather is wet and cool.
Peach leaf curl can be controlled by applying one spray (Ferbam, Bordeaux, or Lime sulfer) before bud swell or in the autumn after most of the leaves have fallen. Once the current year's leaves become infected, they cannot be treated effectively.
This article originally appeared in the June 5, 1991 issue, p. 98.