The resistance of tomato gray mold to gray mold varies from place to place. It is recommended to use fludioxonil or iprodione or Trichoderma or procymidone or eugenol or boscalid alternately. .
As the temperature drops, greenhouse vegetables such as tomatoes and cucumbers are prone to gray mold, which rarely occurs under open air conditions. Outbreaks of gray mold in many areas are difficult to control. Gray mold is mostly contracted from the fruit stems. Fruit infection with gray mold causes fruit rot. The first infection of gray mold mostly comes from the soil, and it is also a soil-borne disease.
However, gray mold has its own special rules. The suitable temperature for the onset of the pathogen is 18-23°C, the lowest temperature is 4°C, and the highest temperature is 32°C. It is difficult to develop if the temperature is below 8°C or 30°C. . The flowering period is the peak period for pathogen infection, and the fruit enlargement period is the peak period for increasing tomato yield by using quick vine fertilizers skillfully. The remaining stigmas or petals are often infected first, and then expand to the fruit stem or surface. The fruit is damaged, and the diseased part becomes soft and rots, resulting in direct loss of yield.
Attention should be paid to the following operations:
1. Use the closed characteristics of the greenhouse to create an ecological environment of high temperature and low humidity. The humidity in the greenhouse is as high as 90% at night. After pulling the thatch in the morning, the vents should be opened immediately to ventilate and remove moisture, lower the indoor temperature, and control the development of diseases at a lower temperature. When the indoor temperature rises and accelerates after 9:00, close the vents to quickly increase the indoor temperature to 35°C to reduce indoor air humidity at high temperatures and control the occurrence of the disease. After 14:00, gradually enlarge the vents to speed up moisture removal; before covering the thatch, as long as the room temperature is not lower than 16°C, try to open as large a vent as possible.
2. Remove diseased flowers and leaves promptly. Many farmers use hormones to dip the flowers into the flowers. The petals are easy to stick to the fruit stems, which are very fragile. When the humidity in the shed is high, water droplets, fog droplets, etc. are also easy to drip on the fruit stems, so gray mold often manifests on the fruit stems.
3. Botrytis spores reproduce quickly when there is sugar. When tomatoes change color, the sugar content increases. This is a time when it is easy to be infected with gray mold, and it is also the key time to apply medication. During this period, use Solanaceae and Diliwang spray in advance. When the disease is high, you can mix it with garlic oil, chemicals, etc.