Control methods of coal mildew of bean

Bean coal mildew, also known as bean leaf mildew, when the disease is serious, it will cause leaf drying and early shedding, which brings huge economic losses to farmers. So what are the symptoms when bean coal mildew is harmed? How to prevent and cure it? Come and have a look with the editor.

1. Harmful plants

Pulverized coal mildew mainly harms leaves, and in serious cases, it also harms vines, petioles and pods. The disease spot initially shows inconspicuous yellow-green spots, then purple-brown or purplish red spots appear in the yellow-green treatment, gradually expanding, and the edge of the spot is not obvious. When the leaves turn yellow, throwing around the disease spot can keep green, when the humidity is high, the disease spot surface will produce dark gray or grayish black soot mold, especially the back of the leaf is more dense. Plaques sometimes combine with each other to form large amorphous plaques. When the disease is serious, the diseased leaves bend, dry up and fall early, and only young leaves remain at the tip.

2. Occurrence regularity

Spring greenhouse bean coal mildew began to occur in mid-April, June-July is the peak of the disease, in the high temperature and humidity environment is conducive to the outbreak of the disease, and the incidence will be more serious. The disease of coal mildew of beans is often serious in continuous cropping land, and the disease of beans sown in spring is often more serious than that of late sowing, especially those sown in spring.

3. Prevention and control methods

First of all, the varieties with strong disease resistance should be selected to increase the disease resistance of the plant, and then it should be planted in a reasonable and close way to maintain good permeability in the field so as not to induce disease caused by excessive humidity. In the rainy season, we must strengthen the drainage work in the field, so as to avoid stagnant water and retting the root, give the bacteria the opportunity, and reasonably increase the application of phosphorus and potassium fertilizer, which can enhance the disease resistance of the plant. The diseased leaves should be removed in time when coal mildew occurs, and the diseased bodies in the field should be removed in time, burned or buried in time. In the early stage of the disease, methyl topiramate, Sukeling, Xinwansheng and sulfur suspension agent Chicken Heart can be sprayed every 10 days for 2-3 times, or dibenzotriazole EC is sprayed every 10-20 days.

The above is the introduction of prevention and control methods of bean coal mildew, hope to help you, want to know more related knowledge, please pay attention to us.