Codonopsis root rot

The pathogen is a half-known fungus in fungi, which can be divided into two types: chronic disease and acute disease. The chronic type began to develop in mid-May and late May. At the initial stage of the disease, dark purple spots appeared in the lower fibrous root or lateral root, and then blackened and rotted. After the disease spread to the main root, it gradually rotted from the bottom up. The rest of the unrotten parts are mostly "half-cut ginseng", close to the rotten part is dark brown, and the aboveground stems and leaves gradually turn yellow, resulting in death. Acute type, mostly in mid-June, late June began to attack, ginseng root once infected, the whole ginseng root almost at the same time, showing water stains, texture becomes soft, vascular bundles become light brown, a few days after the whole ginseng soft rot. After decay, a small amount of gray-white mildew can be seen.

Prevention and control measures: implement crop rotation, avoid continuous cropping; carefully select seeds before sowing, eliminate diseased species, carry out seed disinfection, use robust Codonopsis pilosula plants without diseases and insect pests as transplanting seedlings, and do a good job of drainage and waterlogging prevention in rainy seasons. during the onset period, 50% dinitrate 200 times solution was sprayed, or 50% bacilli special wettable powder 1500 times solution was used to irrigate.