The latest control methods of cucumber Botrytis cinerea

Cucumber gray mold is a perennial disease in cucumber protected cultivation, which is caused by the infection of Botrytis cinerea. Vegetable farmers often call it fruit rot, mildew and so on. In recent years, the occurrence is becoming more and more serious year by year. Because the fruit is often disturbed and cause rot, let's take a look at the prevention and control methods of cucumber gray mold.

Symptoms of cucumber gray mold

Botrytis cinerea of cucumber began to invade from the failed female flowers, initially produced waterlogged spots on the pedicel, and gradually grew gray-brown mildew layer, causing the floral organs to soften, atrophy and rot, and gradually spread to young melons, and the disease parts of melon strips became yellow at first. White mold was produced in the later stage and gradually turned to light gray, resulting in stop growth, softening, decay and atrophy, and finally rot and fall off. When the leaves are infected, the disease spot is watery at first, and then turns into an irregular light brown spot with obvious edges, and sometimes a small amount of grayish brown mildew layer grows. Under the condition of high humidity, the plaque expands rapidly, forming a large plaque with a diameter of 15mm to 20mm. After the stem vine is infected with the disease, the stem decays and the melon vine breaks, causing rotten seedlings.

Incidence regularity of Botrytis cinerea in cucumber

The pathogen overwintered with hyphae, conidia and sclerotia attached to the diseased body or left in the soil, and spread by wind, rain and agricultural operations. the melon-bearing stage of cucumber is the peak period of pathogen infection and disease, high humidity (over 94% relative humidity), low temperature (18 ~ 23 ℃), lack of light and weak plant growth are easy to occur, and stop spreading when the temperature exceeds 30 ℃ and the relative humidity is less than 90%. Therefore, the disease mostly occurs in the greenhouse with low temperature and low light in winter.

Control methods of Cucumber Botrytis cinerea

1. Remove the remains of diseased plants: thoroughly remove the remains of diseased plants in the later stage of harvest, turn the soil more than 20 cm deep, turn the diseased remains left over from the soil surface into the bottom layer, spray soil disinfectant and new high-fat film to disinfect the soil, and reduce the source of primary infection in the greenhouse. At seedling stage and before melon expansion, diseased flowers, diseased melons and diseased leaves were removed and buried deep outside the greenhouse and greenhouse to reduce the source of re-infection.

2. Strengthen cultivation management: strengthen ventilation, appropriate amount of watering, avoid watering in cloudy days, prevent excessive temperature, pay attention to heat preservation, and prevent the invasion of cold current. In the high temperature season, irrigate deeply in the greenhouse and greenhouse, and fish out the floating objects on the water surface, concentrate and bury them or burn them, so as to keep the greenhouse and greenhouse clean.

3. Adjust the temperature and humidity: the bacterial infection can be controlled by adjusting the temperature and humidity in the planting greenhouse. The indoor temperature is raised to 31: 33 ℃, the air is released when it is over 33 ℃, the temperature is maintained at 20: 25 ℃ in the afternoon, and the tuyere is closed when it is reduced to 20 ℃, so that the night temperature is kept at 15: 17 ℃.

4. Disinfection and sterilization in greenhouse. Seedling shed or production shed before planting with 5% Sukeling smoke agent 1 kg per mu closed shed fumigation for 24 hours, Scarlett 40% suspension 1000-1500 times liquid, or 50% prohydantoin suspension or wettable powder 800x liquid, or 70% thiram 300x solution omni-directional spraying.