Once infected leaves drop, no further symptoms will appear during that growing season. Diseased twigs become swollen and stunted, and may have a slight golden cast. They usually produce curled leaves at their tips. Though rarely seen, flowers and fruit may also become diseased. They drop shortly after they are infected.
Diseased fruit has shiny, reddish, raised, warty spots.
Causal Organism Peach leaf curl is caused by the fungus, Taphrina deformans . Infection occurs very early in the growing season. During cool, wet spring weather the conidia infect new leaves as they emerge from the buds. Host plant tissues are susceptible for only a short period. As the tissues mature they become resistant.