How to prevent and control peach leaf brown spot and shot hole disease? Detailed explanation of prevention and control methods

Occurrence pattern: The pathogen mainly overwinters as mycelium on diseased leaves or in the diseased tissues of affected shoots. In the spring of the following year, as temperatures rise and rain arrives, the pathogen produces conidia. The conidia spread by wind and rain, infecting leaves, new shoots and fruit.

The disease occurs more severely in orchards on low-lying land with poor ventilation and damp, shady conditions, or in rainy years.

Prevention and control methods:

(1) Agricultural control: reasonable pruning. Keep the orchard well ventilated and well lit, reduce humidity in the peach orchard, and create conditions unfavorable for the disease.

(2) Manual control: Sweep up fallen leaves and fallen fruit on the ground and burn them in a centralized manner to eliminate the overwintering source of the pathogen.

(3) Chemical control: Before the peach trees sprout (bud swelling stage), spray the whole tree evenly with 4-5 degrees Baume lime sulfur mixture, or 1:1:100 Bordeaux mixture, or 40% asomate wettable powder at 100 times dilution, to eliminate the pathogen source overwintering on the branches. Starting from the stage when small peaches shed their calyx, spray once every 10-14 days with 65% zineb wettable powder at 500 times dilution, or 70% mancozeb wettable powder at 700 times dilution, or 75% chlorothalonil wettable powder at 500-600 times dilution, or 50% iprodione wettable powder at 1500 times dilution, or 50% procymidone wettable powder at 1500 times dilution.