Occurrence and control of peanut bacterial wilt

Peanut bacterial wilt, commonly known as "green disease", "dead seedling", "plague" and "dead vine", is an important disease in peanut producing areas. The incidence rate of general plots is 10%-25%, and the incidence of serious plots is more than 50%. Peanut bacterial wilt (Ralstonia solanacearum) is a typical vascular disease, which can occur in the whole growth period of peanut, but the most common disease is in flowering stage. The pathogen mainly infected the root, first made the main root tip discolor and soft rot, initially made the ducts and other tissues turn light brown, then dark brown, and developed from the root to the aboveground part to the top of the plant. Discoloration and necrosis of vascular bundles can be seen when the disease is cross-sectioned, and milky white turbid bacterial pus droplets can be seen by squeezing the disease root with hands. The symptoms of the diseased plants were not obvious at the initial stage, but began to appear after 3 or 4 days. The main performance was that the leaves opened late in the morning and closed early in the afternoon, and first showed water loss and wilting on the second leaf at the top of the main stem, and the lateral branch leaves were sagging. After 2 or 3 days, the whole plant withered, but the leaves remained light green.  control methods: first, disease-resistant varieties should be selected, such as Luhua 3, Wanhua 2 and so on. The second is to implement the rotation of flood and drought. In recent years, we have generally adopted the rotation system of rice and peanut, which has basically controlled the occurrence of peanut bacterial wilt. Under the condition that there is no water source, it is best to use the method of rotation every two years. The third is to carry out chemical prevention and control. The peanut rosette stage and early flowering stage can be prevented and treated twice with 500 times solution of 5% bacteriological clear water agent or 500 times 800 times solution of 50% compound carbendazim suspension; or holes of 10 cm to 17 cm in diameter can be dug every 30 cm in peanut field, 3 ml 90% chlorinated bitterness can be injected into each hole, and the plastic film can be covered with solid topsoil, and the film can be removed after 7 days.