A Detailed Guide to the Latest Control Methods for Cowpea Sooty Mold

Cowpea sooty mold, also known as cowpea leaf mold, can cause leaves to dry up and drop early when the disease is severe, bringing huge economic losses to farmers. So what symptoms appear when cowpea sooty mold causes damage? How should it be controlled? Let's take a look together.

1. Damage to plants

Cowpea sooty mold mainly damages leaves, and in severe cases also damages vines, petioles and pods. The lesions initially appear as inconspicuous nearly round yellow-green spots, then small purple-brown or purplish-red dots appear within the yellow-green spots, gradually expanding, with the lesion edges indistinct. When the leaves turn yellow, the area around the lesions can still remain green. When humidity is relatively high, a dark gray or gray-black soot-like mold grows on the surface of the lesions, especially densely on the underside of the leaves. The lesions sometimes merge with each other to form irregular large patches. When the disease is severe, the diseased leaves curl, dry up and drop early, leaving only the young tender leaves at the tips.

2. Occurrence pattern

In spring greenhouses, cowpea sooty mold begins to occur in mid-April, with the peak incidence from June to July. High temperature and high humidity conditions favor the outbreak of this disease, and the incidence becomes more severe. Cowpea sooty mold often occurs severely in continuous cropping land, and spring-sown cowpea often suffers more severe disease than late-sown cowpea, especially cowpea sown relatively early in spring, which has the most severe incidence.

3. Control methods

First, choose varieties with strong disease resistance to increase the plants' disease resistance. Then, when transplanting, plant at a reasonable density to maintain good air circulation in the field, so as to avoid excessive humidity that induces disease. During the rainy season, be sure to strengthen field drainage to avoid waterlogging that damages the roots and gives pathogens an opportunity. At the same time, reasonably increase the application of phosphorus and potassium fertilizers, which can enhance the plants' disease resistance. When cowpea sooty mold occurs, diseased leaves should be removed promptly. At harvest time, promptly clear diseased plant residues from the field and burn or deeply bury them in time. In the early stage of the disease, spray thiophanate-methyl, procymidone, xinwansheng, or sulfur suspension concentrate for control, spraying once every 10 days for 2-3 consecutive treatments, or spray diphenoconazole emulsifiable concentrate once every 10-20 days.

The above is an introduction to the control methods for cowpea sooty mold. We hope it can help you. To learn more related knowledge, please follow us.