Evaluation of the Resistance of Some Common Peach and Nectarine Cultivars in Iran to Taphrina deformans, the Causal of Peach Leaf Curl Disease

Leaf curl is a serious disease on peaches and nectarines. Planting of resistant varieties is one of the best ways to prevent and control this disease. In this research, 17 peach and nectarine cultivars were evaluated for susceptibility to the causative agent of peach leaf curl. The results of the evaluations in the first year indicated that, the highest disease severity was related to the Caldesi 2000 and July Alberta cultivars, based on the reaction type of cultivars, they were placed in the sensitive group (S). Then, Red Skin, Baby Gold, Springtime and Antonia cultivars had the highest disease severity and all of them were classified as semi-resistant (MR) cultivars. In contrast, Amesdan, Redhaven, Springcrest and Fayette respectively had the lowest severity of the disease, and all were highly resistant (HR). In the second year of evaluation, Springtime and Caldesi2000 cultivars had the highest rate of disease severity and according to the reaction type of cultivars, both of them classified, highly susceptible (HS). Then July Alberta and Baby Gold cultivars were susceptible to disease (S). In contrast, Amesdan, Redhaven and Robine cultivars had the lowest severity of disease and according to the type of cultivars reaction were classified highly resistant (HR). Therefore, according to the results of two years evaluation, it can be said that the cultivars Caldesi2000, Springcrest,then July Alberta and Baby Gold are the most susceptible and Amesdan and Redhaven are the highest resistance to the peach leaf curl disease.