What pesticide works well to prevent and control yellow leaf disease in cowpeas?
Cowpeas inevitably develop yellow leaves during growth, so what pesticide should be used for yellow leaf disease in cowpeas? It needs to be analyzed according to the specific situation.
1. Why do cowpeas develop yellow leaves?
During the growth of cowpeas, poor field management can easily lead to yellow leaves, and the causes of yellow leaves in cowpeas are also varied:
1. Pathogenic pathogens in the soil may cause cowpeas to suffer from root rot. After cowpeas suffer from root rot, the lower leaves will turn yellow, and the plants will wilt at high temperatures at noon and recover in the morning and evening;
2. Cowpeas lacking trace elements will also develop yellow leaves, specifically showing yellowing of the top leaves, generally caused by iron deficiency and zinc deficiency;
3. If the plants are not kept warm enough, or if the temperature is too high, the leaf veins of cowpeas may turn yellow. In addition, improper pesticide use can also cause this problem, and it needs to be analyzed according to the specific situation.
2. What pesticide should be used for yellow leaf disease in cowpeas?
1. For yellow leaves in cowpeas caused by root rot, the soil needs to be disinfected and sterilized, and carbendazim should be used to drench the roots;
2. For yellow leaves in cowpeas caused by trace element deficiency and root rot, foliar fertilizer can be sprayed appropriately to supplement nutrients;
3. For yellow leaves in cowpeas caused by temperature or improper pesticide use, Bihu, brassinolide, and similar products should be sprayed on the plants, and attention should be paid to reasonable watering and heat preservation.
3. Field management for cowpea cultivation
1. Planting cowpeas requires soil with a deep soil layer, and the soil texture should also be somewhat loose, so that drainage and irrigation are convenient. At the same time, drainage and irrigation ditches should be dug well to prevent waterlogging and root rot;
2. Cowpea growth requires sufficient sunlight, reasonable watering, and appropriate fertilization. Generally, after the plants bloom and form pods, apply topdressing 2-3 times, using 5-15 kg of urea per mu each time. During the harvest period, also apply topdressing once with water, applying 25 kg of diammonium phosphate per mu, or 25 kg of potassium dihydrogen phosphate.