How to prevent and control peach leaf curl? Those growing peach trees should know early

1. Symptoms and damage

This disease occurs from time to time in the south. When severe, it causes branch dieback and affects ornamental value. The disease mainly damages leaves. When leaves unfold in early spring, the leaf margins curl downward. Part of or the entire diseased leaf becomes blistered and enlarged, the leaf becomes thicker, brittle in texture, and yellow or red, and the leaves become twisted and deformed. In early summer, a grayish-white powdery layer forms on the diseased parts. When the disease is severe, the leaves fall early. When young shoots are damaged, they appear grayish-green or yellow, with short and thick internodes and slight bending; the upper leaves cluster and curl. When the disease is severe, the branches die.

2. Pathogen and disease characteristics

This disease is a fungal disease caused by Taphrina deformans (Berk.) Tul. The pathogen overwinters or oversummers in bud scales or diseased parts of branches and trunks; it spreads by wind and rain; it invades through stomata and other openings. Low temperatures (10°C-16°C) and abundant rain favor disease occurrence. The peak period of disease occurrence is early to mid-May. Above 21°C, disease occurrence stops.

3. Prevention and control methods

(1) Reduce sources of infection: Before peach buds swell and open, spray 45% lime sulfur crystal at 150 times dilution, or 1% Bordeaux mixture, to kill overwintering inoculum. Continuous control for 2-3 years can eradicate peach leaf curl. After leaf fall, spray 2%-3% copper sulfate solution, and the disease will be mild the following spring.

(2) Cultivation techniques for disease prevention: Apply more organic fertilizer or GA activator; drain promptly after rain; prune diseased branches during pruning and destroy them together with diseased fallen leaves.