What are the control methods for peanut root rot?
In recent days, many farmers have brought peanut leaves to the shop to ask what is going on. On the surface, the leaves are yellowing, and some farmers think it is a lack of nutrients, but in fact it is mainly caused by root rot. A while ago, rain was frequent, making the soil damp and poorly aerated, which caused root soaking and root rot, so the roots could not absorb nutrients and the leaves turned yellow. If not treated in time, the yield will be greatly affected. The symptoms, causes, and control methods of peanut root rot are summarized as follows:
1. Symptoms. Root rot is commonly known as “rat tail” or rotten root. It can occur at all growth stages. When it infects newly germinated seeds, it causes seed rot: when seedlings are affected, the main root turns brown and the plant wilts. When mature plants are affected, sunken long strip-shaped brown lesions appear on the main root and root crown, the root tip becomes wet and rotten, the cortex turns brown and rots, and it easily separates and falls off, with no lateral roots or very few, resembling a rat tail. When moist, adventitious roots grow from the root crown. Affected plants are short above ground, grow poorly, have yellowing leaves, and bear few flowers and fruits, mostly shriveled pods.
2. Transmission routes and disease conditions. The pathogen overwinters in soil, diseased residues, and seeds, becoming the primary infection source the following year. The pathogen is mainly spread by rain and farming operations, directly invading through wounds or the epidermis, and diseased plants produce conidia for secondary infection. During the seedling stage, frequent rain and high humidity lead to severe disease. Continuous cropping fields, shallow soil layers, and sandy soils are prone to the disease.
3. Control methods
1. Practice crop rotation. Rotate lightly diseased fields for 3 to 5 years.
2. Deep plow and improve the soil, apply more organic fertilizer, and carry out reasonable drainage and irrigation to enhance disease resistance.
3. Before sowing, mix seeds with 50% carbendazim wettable powder. This can effectively reduce the disease incidence.
4. Chemical control: use 1000-fold Enze mold solution together with foliar fertilizer, or use 1000-fold 80% ethylicin solution together with foliar fertilizer and spray on the leaves to control the spread of the disease.