Control techniques of peach blossom leaf shrinking disease

Symptoms and Harm

The disease occurs in the south, when seriously ill, it causes branches to wither and affects viewing. The disease mainly affects leaves. Early spring when the leaf expansion edge downward curl, local or whole leaf disease proliferation into blister, leaf thickening, brittle texture, yellow or red, leaf distortion deformation. In early summer, the diseased part is covered with gray powder layer, and the leaves fall early when it is seriously ill. Young shoots are greyish green or yellow when damaged, internodes are short and thick, slightly curved; upper leaves are clustered and curled. The branches die when they are seriously ill.

II. Pathogen and characteristics

The disease is a fungal disease caused by Taphrinadeformans (Berk.) Tul.] caused. Pathogens overwinter or oversummer in bud scales or diseased parts of branches; spread by wind and rain; invaded from stomata, etc. Low temperature (10℃~16℃) and heavy rain are conducive to disease occurrence. The peak period of the disease was in the early and middle of May. Disease occurrence stagnated above 21℃.

III. Prevention and control methods

(1) Reduce infection source: spray 45% stone sulfur mixture crystal 150 times solution or 1% Bordeaux mixture before peach bud expansion to kill overwintering bacteria source. The disease could be eradicated by continuous control for 2~3 years. Spraying 2%~3% copper sulfate solution after defoliation will cause light disease in the following spring.

(2) Cultivation techniques for disease prevention: apply organic fertilizer or GA activator; drain water in time after rain; combine pruning to cut off diseased branches and destroy them together with diseased leaves.