Peach leaf curl is another one of those plant diseases where control is not possible once the symptoms are obvious. The peach leaf curl fungus, Taphrina deformans, survives the winter in bark crevices and on bud scales. With the help of spring rains, the fungus finds its way to leaves as they begin to emerge.

A single fungicide spray in the fall after leaf drop or in the spring before the buds swell can prevent the disease. Timing is important. Several fungicides, including Bordeaux mixture, liquid lime sulfur, chlorothalonil (Daconil and others), and copper hydroxide are effective for control of peach leaf curl.

Once the current year's leaves become infected they cannot be treated. Diseased leaves show a thickened, puckered appearance with a pink-red color. Later in the season infected leaves turn gray and fall prematurely from the tree. Diseased fruits are distorted and seldom remain on the tree until harvest. Trees weakened by disease are more susceptible to winter injury.

This article originally appeared in the March 10, 2000 issue, p. 19.