What are the latest control methods for peanut stem rot?
Peanut stem rot is a relatively serious disease in the process of peanut cultivation. It mainly damages the roots and root crown, and can also damage stems, leaves and pods. This disease generally reduces yield by 10-20%, causing great harm, so how should stem rot be controlled? Let's take a look together.
1. Disease symptoms
Peanut stem rot is the general term for large sclerotium disease and small sclerotium disease, and the symptoms caused by large sclerotium disease are similar to those of small sclerotium disease, but the former only occurs on the stems and vines, and produces larger sclerotia in the later stage. When leaves are infected, the lesions become dark brown, nearly round, and when moist, the lesions become water-soaked, softened and rotted. When the stem is infected, the lesions turn brown, or gradually become dark brown, and finally black-brown, collectively known as stem soft rot, and the plant wilts and dies. Under moist field conditions, the lesions will produce grayish-brown mold-like matter and grayish-white powdery matter, namely mycelium and conidia. After harvest, the pods turn brown, and black sclerotia are produced on the surface, causing the seeds to rot or shrink.
2. Transmission routes
The pathogen overwinters in the form of sclerotia in diseased residues, pods and soil, and the mycelium overwinters in diseased residues. After the temperature rises in the second year, the small sclerotia will germinate to produce mycelium and conidia, and sometimes also produce apothecia, releasing ascospores, invading the plant through wounds, and can also spread with wind and rain, while the mycelium can also directly invade the host. The sclerotia of large sclerotium disease, however, directly produce apothecia, release ascospores and carry out infection.
3. Control methods
Crop rotation should be carried out with crops such as wheat, millet, corn and sweet potato, as this can reduce the occurrence of the disease. During the growing period, deep intertillage should be carried out to bury the sclerotia directly into the soil, preventing the production of spores and reducing the chance of disease spread. Once diseased plants are found in the field, they should be pulled out promptly and burned in a centralized manner. After harvest, diseased plants should be removed promptly, and intertillage should be carried out to bury the residual plants and sclerotia left in the field together into the soil, reducing the source of the pathogen and lessening the occurrence of the disease. In the early stage of the disease, chemicals can be sprayed for control, and sprayed again after 7-10 days. The chemicals that can be selected include validamycin wettable powder, compound dimethachlon, iprodione wettable powder, etc.
The above is an introduction to the control methods for peanut stem rot. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.