Prevention and control of peach blossom and leaf shrinking disease in planting peach trees

I. symptoms and harm

The disease occurs from time to time in the south, and when the disease is serious, it causes branch blight and affects ornamental. The disease is mainly harmful to leaves. In early spring, the leaf margin curls downward, the local or whole leaves of the diseased leaves become blister-like, the leaves become thicker, brittle, yellow or red, and the leaves are twisted. The disease is covered with gray-white powder layer in early summer, and the leaves fall early when the disease is serious. The young shoots were grayish green or yellow when damaged, the internodes were short and thick, slightly curved, and the upper leaves were clustered and curled. The branches withered when they were seriously ill.

2. Pathogens and characteristics of the disease

The disease is a fungal disease caused by Taphrinadeformans (Berk.) Tul. Cause. The pathogen overwintered or oversummed in the diseased parts of bud scales or branches; spread by wind and rain; invaded from stomata, etc. Low temperature (10 ℃ ~ 16 ℃) and heavy rain are beneficial to the occurrence of the disease. The peak period of the disease is in the first and middle of May. Diseases above 21 ℃ stagnated.

III. Prevention and control methods

(1) reduce the source of infection: spray 45% stone-sulfur mixture 150 times liquid, or 1% Bordeaux solution, before peach bud expansion to kill the source of overwintering bacteria. The leaf shrinking disease can be eradicated by continuous prevention and treatment for 2 to 3 years. Spray 2%-3% cupric sulfate after falling leaves, and the disease will be mild in the next spring.

(2) cultivation techniques for disease prevention: application of organic fertilizer or GA activator; timely drainage after rain; combined with pruning to remove diseased branches and destruction together with diseased leaves.