The latest control methods of white silk disease of peanut

Peanut white silk disease is one of the main diseases that harm peanuts. Peanut roots, pods and stem bases are initially brown and soft rotted after being damaged. There are white silky hyphae at the root of the ground. White silk is often formed at the base of the stem near the ground and on the soil surface nearby. The diseased part gradually changes to dark brown and shiny. Let's take a look at the prevention and control methods of peanut white silk disease.

Peanut white silk disease harm symptoms

Under high humidity conditions, infected plants can be covered by white hyphal bundles above ground, which then spread to nearby soil and infect other plants. In extremely humid conditions, hyphal clusters are not evident, and the base of the affected stem is covered with long fusiform spots with pale brown to red corky bumps. Under drought conditions, the disease mark on the stem occurs under the ground surface, brown fusiform, about 0.5 cm long, and has rapeseed seed-like sclerotia, stem and leaf turn yellow, gradually die, peanut pod rot.

Conditions of white silk disease of peanut

The fungus overwinters as sclerotia or hyphae in soil or on diseased bodies and can survive for 5~6 years. Most of them are distributed in the topsoil layer of 1~2 cm. The germination rate of sclerotia decreased obviously below 2.5 cm and hardly germinated at 7 cm in soil. Sclerotia germinate in the following year, produce hyphae, invade from the epidermis or wound at the base of the plant rhizome, and can also invade the ovary stalk or pod. Seeds can also carry bacteria. Pathogens spread by running water or insects in the field, high temperature, high humidity, heavy soil viscosity, poor drainage, low-lying land and rainy years easy to occur, immediately turn clear after rain, sick plants quickly wither and die, continuous cropping, early sowing disease heavy.

Control method of peanut white silk disease

1. After harvest, remove the sick and disabled body in time, deeply turn, rotate with rice, wheat, corn and other gramineous crops for more than 3 years, advocate the application of compost or decomposed organic fertilizer made by enzyme bacteria, and improve the soil permeability conditions.

2. Spring peanuts should be sown late, and the seedlings should be cleared to improve disease resistance. At the same time, disease-free seeds are selected, 50% carbendazim wettable powder with 0.5% seed weight is used for seed dressing, and after the disease occurs, 1kg of 50% seed dressing double powder is mixed with 15kg of fine dry soil to prepare medicine soil for covering the disease holes, and 75g of medicine soil is used for each hole.

3. Spray Fengqigenbao 600-800 times or 50% benomyl wettable powder or 50% prohydantoin wettable powder or 50% procymidone wettable powder, 20% chloraz methyl emulsifiable concentrate 1000 - 1500 times, spray 100 - 200 ml of good solution for each plant.