STM Article Repository

Peach leaf curl is caused by Taphrina deformans, a biotrophic parasitic fungus. About 90% of the peach acres are treated for this destructive disease. Leaves produced in the spring are deformed, thickened, curled, and colored red or yellow instead of normal green. Severely affected shoots die. Irregular reddish lesions are sometimes seen on the fruit where touched by infected leaves. Badly diseased leaves fall by early summer, and repeated infections debilitate trees and kill branches. Dormant applications are necessary in all peach growing districts. One application in late winter before buds well is sufficient except in areas of high rainfall or where leaf curl has become an increasing problem. In these cases, the use of resistant or tolerant cultivars will be of great interest. Infection requires at least 12 hours of moisture (high humidity or rain) and temperatures between 10°C and 21.5°C. In this technical document, we are dealing with peach leaf curl: symptoms and signs, epidemiology, disease cycle, ecology and disease management.