In the winter and spring season, vegetable seedlings in greenhouses are subject to disease. Due to the low seedbed temperature, lack of light, poor ventilation, and high humidity, the seedlings are susceptible to disease and often cause seedling failure. Its prevention measures are: 1. Use bedless soil. When growing vegetables, it is best to use fertile, field soils that have not been sown with solanaceous fruit, melons, and cruciferous vegetables for 5 consecutive years. Sandy soil is better, and care should be taken to select 13-17 cm. Within the topsoil; avoid using garden soil as bed soil. In order to prevent the spread of soil bacteria, bed soil can be disinfected and treated in many ways. Commonly used methods are: (1) Carbendazim disinfection. 5-30% carbendazim wettable powder 25-30 grams per 1000 kg bed soil, when processed, first carbendazim into an aqueous solution, and then sprayed on the bed soil, mix well and cover it with a plastic film, generally by 2 -3 days to kill various pathogens such as blight in the soil; (2) Formalin disinfection. The formalin, water, and bed soil were sprayed and mixed evenly at a ratio of 1:100:4000-5000, and then piled up and covered with a plastic film. After 2-3 days, the film was peeled off to promote the emission of drug gas. In this way, it can be used after 1-2 weeks; (3) Methane disinfection. The bed soil was piled up into a 30-cm-high mound, and a 10-15 cm deep hole was drilled every 30cm square in the upper part of the mound. Each hole was filled with 5 milliliters of medicine, and then the hole was plugged. After the application, a layer of soil of the same thickness is piled on top and the pesticide is applied in the same way until all the bed soil is treated. Finally, the entire mound is sealed with a plastic film, which can kill a variety of germs and pests in the soil after 7-10 days. When used, fully turn the mound and disperse the gas to prevent phytotoxicity. 2. Seed treatment. Seed soaking in warm water at 50°C for 15 minutes, followed by cooling with cold water, drying after sowing, with obvious disinfection effect. In addition, 50% carbendazim or 50% thiram can also be used for seed dressing. The dosage is 0.3% of the seed amount. 3. Strengthen cultivation management. Planting water before planting sowing, and appropriate sparse planting, strong seedlings; timely and appropriate amount of water, control seedbed humidity, to prevent excessive watering, over-attendance; pay attention to insulation, antifreeze, to prevent seedbed temperature is too low; strengthen ventilation, To prevent excessive air humidity in the seedbed and harmful gas harm vegetable seedlings; to increase light as much as possible, in the case of ensuring the temperature of the seedbed, appropriate early exposing and late cover, even in cloudy snow weather, we must properly uncover the grass seedlings to prevent The temperature is too high and the seedlings grow in length; the seedlings are divided early in time to prevent the seedlings from being damaged by the roots. 4. Chemical control. At the early stage of disease, the diseased seedlings are firstly removed and then sprayed and protected in time to prevent the spread. Commonly used agents are: copper hinge (copper sulfate 2 parts, add 11 parts of ammonium carbonate, mix well, seal after 24 hours) 400-500 times liquid, 50% carbendazim 600 times liquid, 75% Chlorothalonil or 70% Trichlorfen wettable powder 600-800 times solution and 0.1-0.2% copper sulfate solution. After spraying, in order to prevent the humidity of seedbeds from being too large, weeds can be damped with grass ash or fine dry soil. Edible Starch Mixer,Starch Mixer,Coupling Starch Mixer,Yam Starch Mixer Shuangfeng County Dingyuan Machinery Manufacturing Co. Ltd.. , https://www.separators.pl