Control methods of leaf blight

Leaf blight, also known as blight, is common in plants and can usually occur from July to October. The main damage sites are leaf edge and leaf tip. In the lower part of the plant, the disease is serious, high temperature, humidity and poor ventilation are conducive to the occurrence of the disease. The disease of weak plant growth is more serious. Let's take a look at the prevention and control methods of leaf blight.

Harmful symptoms

Leaf blight mostly occurs from leaf edge and leaf tip, and the disease spot is irregular from small to large, reddish brown to grayish brown, and the disease spot is continuous into a large blight spot, and the dry area is up to 1 inch, 1 inch, 2, the edge of the spot has a deeper zone than the spot, the disease boundary is obvious, and sometimes there are shallow yellow bands with different width and width on the outer edge of the spot. Subsequently, the disease spot gradually extends to the base of the leaf until the whole leaf turns brown to grayish brown. Finally, black villi or black dots appear on the back or front of the diseased leaves.

Morbidity regularity

The pathogen of leaf blight overwintered on the diseased leaves, and the spores of the pathogen spread to the host plant with wind and rain when the temperature was suitable in the following year, which could occur from July to October, and the disease was serious in the lower leaves of the plant. high temperature, humidity and poor ventilation are conducive to the occurrence of the disease, and the incidence of weak plant growth is more serious.

Prevention and cure method

1. Thoroughly remove the fallen leaves in autumn and burn them centrally, so as to reduce the source of infection in the following year.

2. The planting land should be well drained, the soil should be fertile, and organic fertilizer, phosphorus and potassium fertilizer should be applied.

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

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

5. In the growing season, it can be effectively prevented and treated by spraying medicine every 10 days or so from the initial stage of the disease in late June to October. The commonly used medicaments are 100 times Bordeaux solution, 50% topiramine 500 times 800 times, 50% carbendazim wettable powder 1000 times (or 40% colloidal suspension 600 times 800 times), 50% benzoate 1000 times 1500 times, 65% Dysen zinc 500 times, etc., which can be used alternately.