How to Control Botrytis cinerea in Tomato caused by Botrytis cinerea

Tomato flowers, fruits, leaves and stems can be infected with Botrytis cinerea. Most of the infected fruits were residual stigmas or petals, and then extended to tomato or fruit stalk, resulting in grayish white tomato skin and thick gray mildew layer. Leaf gray mold was first infected from the leaf tip, spread inward in the shape of "V" along the branches, showed water immersion at first and yellowish brown after expansion, and there were dark and light striated lines on the edge of the leaf. The demarcation line between disease and health is clear. When the stem is infected with Botrytis cinerea, it begins to show a small spot in the form of water, followed by an oblong or striped spot, light brown. When the humidity is high, there is a gray mildew layer on the surface of the disease spot, which can lead to death.

Tomato gray mold

Route of transmission and conditions of onset: Botrytis cinerea is caused by Botrytis cinerea. When the temperature is 20-30 ℃ and the relative humidity is above 90%, it is the suitable condition for the occurrence of the disease. Tomato protected areas are generally susceptible to disease from December to May of the following year. Germs spread through airflow, irrigation water and farming operations. The main route of man-made transmission is stained flowers, bacteria invade from wounds, senescent organs and other dead tissues, and the flowering period is the peak period of infection.

Prevention and control methods:

Ecological control. The tomato protected area is mainly to control the temperature and humidity of the greenhouse. Generally late in the morning, more than 30 ℃ to start the ventilation, when dropped to 25 ℃, continue to release at noon, the afternoon temperature maintained at 20: 25 ℃, to 20 ℃ to stop the release, in order to keep the night temperature between 15: 17 ℃, cloudy days open vents for ventilation.

Strengthen cultivation management, when planting, apply sufficient base fertilizer, watering to avoid rainy days, after watering, should release wind and drain moisture, after disease, control watering, infected tomatoes and leaves should be removed in time and concentrated treatment, after pulling seedlings, remove the diseased and residual bodies, pay attention to the hygiene of agricultural operation to prevent disease.

Chemical control. Emphasis should be placed on the use of drugs in the three key periods of tomato transplanting, flowering and expansion.

Before transplanting ① tomatoes, spray the seedlings with 50% carbendazim or 50% carbendazim or 500 times of wet powder.

② was stained with anther. After planting, combined with flower application, that is, 0.1% 50% promethrin wettable powder or 50% carbendazim wettable powder or 0.2%-0.3% 25% metalaxyl wettable powder were added to the 2.4murD or Fanglutin diluent to stain or smear.

③ fruit enhancer. The pesticide was applied before pouring fruit water or in the early stage of the onset of Botrytis cinerea.

④ smoke was applied. You can choose 10% Shu Ke Ling smoke agent or 45% chlorothalonil smoke remover, 250 grams per mu of tomato each time.

⑤ dust was applied. You can choose 5% chlorothalonil powder, 1 kg per mu of tomatoes, once every 7-10 days, and apply it 2 times in a row.