Peach Leaf Curl Fruit Pathology Penn State Department of Plant Pathology Jim Travis, Jo Rytter and Ken Hickey Peach Leaf Curl Peach leaf curl caused by the fungus, Taphrina deformans , is a common disease of peach and nectarine. This fungus destroys young peach leaves. New leaves will develop, however, their growth reduces established food reserves, weakens the tree, and may reduce yield. Defoliation by peach leaf curl in successive seasons may kill the tree. Symptoms Infected leaves, which begin appearing in mid-May, are easily distinguished from healthy leaves in that they are curled, puckered and thicker than normal.
Deformed areas are red to yellow at first and then turn brown.
Eventually the infected leaves fall from the tree. Symptoms of leaf distortion caused by the fungus, Taphrina deformans When trees are severely infected by the fungus, peach fruit can also become susceptible. Infected fruit exhibit distorted, warty growths on the surface and will usually abort. Disease Cycle Spores of the leaf curl fungus overwinter on the surface of peach twigs. In spring, the spores multiply during periods of moist weather until the leaf buds swell and open.