Prevention and treatment of leaf blight

Leaf blight alias dead spot, found in plants, usually in October 7 to all can happen, the main parts for leaf margin, leaf, the incidence of lower leaves heavy, high temperature high humidity, poor ventilation are conducive to the occurrence of diseases, the onset of plant growth is weak relatively serious, let's take a look at together leaf blight of prevention and cure the!

Hazard symptoms

Leaf blight mainly occurs from leaf margin and tip infection, and the lesions are irregular from small to large, from reddish-brown to grayish-brown, with large blisters and dry areas up to 1/3 to 1/2 of the leaves. There is a deep band of disease spots on the edge of the lesions, with obvious disease and health boundaries.The plaque then gradually extends to the base of the leaf until the entire leaf becomes brown to grayish brown.Finally, black villi or black dots appear on the back or front of the diseased leaf.

Law of

The pathogen of leaf blight disease overwintered the diseased leaves. The next year, when the temperature was appropriate, the spores of the pathogen spread to the host plants by means of wind and rain.

Method of prevention and cure

1. Thoroughly remove the diseased leaves and burn them down in autumn to reduce the source of infection in the following year.

2. The cultivated land should be well drained, the soil is fertile, and organic fertilizer, phosphorus and potash fertilizer should be increased.

3. Control the planting density, make it ventilated and transparent, reduce the humidity of the leaf surface, and reduce the chances of infection.

4. Change spray irrigation to drip irrigation or water irrigation to reduce the spread of bacteria.

5. During the growing season, in the regions with serious diseases, from the early stage of onset in late June to October, spray one dose every 10 days or so, and spray several times can effectively prevent and control the disease.The commonly used agents are 1:100 times of bordeaux liquid, 50% of tobuzin 500 ~ 800 times liquid, 50% of polymyrine wettability powder 1000 times (or 40% of glue suspension 600 ~ 800 times), 50% of benet 1000 ~ 1500 times, and 65% of daisen zinc 500 times liquid, which can be selected or used alternately.