What causes dry leaves on cowpeas? Let me teach you the prevention and control methods
Cowpeas are a common sight in our daily markets, and many problems arise during the growing process. Dry leaves on cowpeas are one of the most troublesome, with the leaves suddenly drying up during cultivation, which seriously affects the growth of cowpeas and also has a certain impact on yield and quality. So what causes this in cowpeas? How should it be prevented and controlled? Let's take a look.
I. Causes of dry leaves
Dry leaves on cowpeas are mostly induced by herbicides. At first, the older leaves of the cowpea dry up while the stems and vines remain green. As the cowpea grows, the new leaves become deformed, with the leaf blades shriveling and becoming uneven. If the cowpea is in the pod-setting stage, flower drop occurs, the plant grows poorly, and yield is seriously affected. In addition, some diseases and pests can also cause dry leaves on cowpeas. The common leaf roller pest, for example, can also cause dry and curled leaves.
II. Prevention and control methods
1. Rinsing with clean water
Herbicides are generally applied over a period of 7-10 days. During this time, water should be sprayed frequently on the stems and leaves of the cowpeas to reduce the residual dose of herbicide on the plants and lessen the dry leaf symptoms.
2. Timely topdressing
When dry leaf symptoms occur, fertilizers based mainly on ammonium bicarbonate or urea can be applied promptly, and an appropriate amount of phosphorus and potassium fertilizer can also be reasonably combined to help the plants recover. The amount of topdressing should be based on the severity of the phytotoxicity and the growth condition of the cowpeas.
3. Timely watering
Water promptly after topdressing, which can promote the release of fertilizer efficacy as quickly as possible and reduce the concentration of harmful substances in the cowpea plants, alleviating the symptoms. Plant growth regulators and foliar fertilizers can also be sprayed on the leaves; a mixture of brassinolide at 7500 times dilution plus foliar fertilizer gives better results. According to the degree of phytotoxicity, spray once every 10-15 days, for 1-3 consecutive times.
4. Pest and disease control
In the early stage of pest occurrence, check and pick off the curled leaves on the cowpea plants and take them out of the field for centralized disposal, or crush the larvae inside the curled leaves by hand, or spray pesticides such as pyrethrin emulsifiable concentrate, cypermethrin emulsifiable concentrate, and fenvalerate for control. Be careful to alternate the pesticides when spraying to prevent the pests from developing resistance.
The above is an introduction to the causes of dry leaves on cowpeas and the prevention and control methods. I hope it can help you. If you want to learn more related knowledge, please stay tuned to us.