Control methods of early Blight of Pepper

Pepper early blight is caused by Alternaria solanum, a subphylum fungus. It overwinters with hyphae or conidia on diseased remains or seeds, and repeatedly infects by airflow and Rain Water. It is easy to become prevalent when the relative humidity of high temperature air is more than 85% at 26-28 ℃. The disease is serious in the north hot summer and rainy season and poor ventilation in protected areas. Let's take a look at the prevention and control methods of pepper early blight.

Harmful symptoms of early Blight of Pepper

After the disease of pepper stalk, brown to dark brown irregular round or oval disease spots are generally produced at the bifurcations, and there are gray-black mildew on the surface of the disease spots. Fruit disease, mostly occurred near the calyx, at first oval or amorphous brown or black spots, obvious depression, to the later stage, the fruit cracking, the diseased part hardened, in the wet condition of the diseased part of the black mildew layer. The disease will also occur at the seedling stage, generally producing dark brown watery spots in the old leaf tip or terminal bud, causing leaf tip and terminal bud rot, forming apical seedlings, and dark green mildew layer can be seen in the later stage of diseased seedlings.

Causes of early Blight of Pepper

Pepper early blight is a fungal disease caused by Alternaria solanacearum. The mycelium and conidia overwintered in the field or seed with the disease residue, and new conidia were produced in the second year. spread by means of wind, Rain Water, insects and so on. The pathogen invaded from stomata or wound, or directly from the epidermis. The incubation period was 3-4 days, and a large number of conidia were produced in the disease part for re-infection. Diseases are easy to occur when seedlings are aging and weak, too dense, too high humidity, poor ventilation and light transmission and so on. Too late planting, moist soil and poor ventilation will accelerate the spread of the disease.

Control methods of early Blight of Pepper

1. Select improved varieties: select excellent varieties with disease resistance, such as Raiyou 4, Ruyou 9, Yuejiao 3, Xiangyan 9, Yujiao 5, etc., do not plant the same variety year after year, but rotate. At the same time, the purpose of disinfection can be achieved by scalding it with 55 ℃ of warm water for 15 minutes.

2. Reasonable management: avoid excessive humidity in the seedling bed, and ventilation and humidity reduction should be done in time after watering the seedling bed. Field planting should be reasonable rotation, high border planting, reasonable close planting, pay attention to trench drainage, timely pruning, in order to facilitate field ventilation, reduce humidity, prevent disease and control the spread of diseases. Applying more phosphorus and potassium fertilizer can promote the robust growth of root system and stem and enhance the disease resistance.

3, chemical control: in the initial stage of the disease, use 75% chlorothalonil wettable powder, or 50% propofoin wettable powder 1000 times, or 64% poison alum wettable powder 600x, etc., alternately, once every 7 to 10 days, spray 2 times continuously for 3 times.