How to control tomato gray mold

Tomato gray mold is the main disease in greenhouse production in spring. It is also a key factor affecting output. Effective prevention or control of botrytis cinerea is the most important thing for tomato high yield in spring. Tomato gray mold mainly harms young fruits and leaves. Tomato leaves infected with gray mold, at the initial stage of infection, the pathogen first infects from the edge of the leaves, showing a small V-shaped lesion, and the lesion gradually expands to the depth of the leaves, forming a large V-shaped lesion with a light gray mold layer on the surface of the leaves. Pathogens invaded from the petals of female flowers after flowering, petals rotted, the top of the fruit stalk began to get sick, and the fruit stalk invaded inward, resulting in gray-white and soft rot of infected young melons, and a large number of gray-green mold layers grew in the later stage. Where bacteria stick, fruits and leaves are infected and rotted there. \x0d\ In terms of control, many vegetable farmers only pay attention to controlling gray mold by spraying leaves or plants. The preventive effect of leaves and plants is very ideal. There are no diseased spots, no rotten leaves, only rotten fruits. Always go to the hospital for consultation. In fact, it is not difficult to fully understand the characteristics of botrytis cinerea and prevent rotten fruit. Botrytis cinerea likes to live in a low temperature and high humidity environment and infect the environment. This also determines that early spring is the peak of tomato gray mold. It overwinters with sclerotia or mycelium and conidia in the soil and on the diseased remains. Invasion of wounds, aging organs and floral organs. Stigma is the susceptible part, which makes the fruit susceptible to diseases and soft rot. Therefore, the flowering period is the peak period of botrytis cinerea infection, and the control of botrytis cinerea should start from the flowering period of tomato, and start with adding chemicals to the tomato flower protection solution. Germs can be transmitted again through airflow, watering and agricultural operations. The suitable initial temperature is 22-25℃ and the humidity is above 90%. Weak light is conducive to the onset. Flooding and cloudy days are the most important factors inducing gray mold. Excessive density, untimely ventilation and weak growth are all conducive to the occurrence and spread of gray mold. \x0d\ If the flower protection liquid such as 2g of He Rui dispersible granules or 65,438+0,500ml lethal suspension, or 3 bags of 4,500ml Guo Mu Ning and 5g of He Rui or 65,438+0 bags of lethal suspension are used to dip and spray flowers during the flowering period of tomatoes, it will have a good preventive effect on the infection of gray mold during the flowering period. If the whole plant cooperates with the whole crop to solve the disease prevention prescription, the ideal harvest effect will be obtained. \x0d\ The general prescription for crop disease control is: after tomato seedlings slowly grow new leaves in the greenhouse, spray pesticide Dyclonine 600 times for the first time, Amisi 1500 times at intervals of 7- 15 days, and He Rui 1000 times at intervals of 15 days. In the future, dyclonine and Sheng Da can be sprayed as appropriate according to the health and harvest of the plants. \x0d\ Prophylactic drug use at the initial stage of onset can be considered as follows: 600 times in dyclonine, 0/500 times in Amisi, and 500 times in Sheng Da. Therapeutic drugs: Spraying He Rui 1200 times, Xerox 1200 times, Rukang 600 times, chlorpheniramine 500 times, Limeikang 500 times, Domicine 600 times, etc.