How to prevent and control ginseng Phytophthora blight? A full analysis of practical methods

Ginseng Phytophthora blight is a major disease of ginseng. It not only damages the stems and leaves of the plant but can also infect ginseng roots, causing wet rot of the roots. In the Russian Far East, losses of 20%-30% of ginseng can occur due to Phytophthora blight. The disease is widely distributed in countries such as China, Korea, Japan and Russia. Its control measures are as follows.

① Use a single-light-transmitting shed. Cover the ginseng bed with mulch such as fallen leaves, rice straw, wheat straw and cogon grass to prevent rain from leaking onto and falling on the ginseng bed, which can control the occurrence and spread of ginseng Phytophthora blight.

② Strengthen ginseng bed management. Keep the ginseng bed well ventilated and exposed to light, with good drainage, to enhance the disease resistance of ginseng. Once diseased plants are found, they should be pulled out promptly, the diseased leaves removed or the diseased roots dug out, and quicklime spread at the site of the diseased roots for disinfection to prevent the infection from spreading.

③ Chemical control. In the early stage of stem and leaf disease, promptly spray 500-800 times diluted solutions of ridomil, phosethyl-Al, metalaxyl-mancozeb, etc., which have protective and therapeutic effects and give significant control results. Chemical treatment of soil and ginseng seedlings is an effective measure for controlling ginseng root Phytophthora blight. Effective agents for soil treatment are 500 times diluted solutions of ridomil, metalaxyl-mancozeb, phosethyl-Al and mancozeb, all of which give good control results, with ridomil and metalaxyl-mancozeb being the most effective.