In the early spring, when greenhouses are used to grow vegetable seedlings, they are prone to frost damage in cold weather and measures should be actively taken to prevent freezing. Increase the light to make the seedlings more light, should be as early as possible to maintain the normal growth of the temperature range, as soon as possible to cover the late cover grass cover and other coverings, even if it is cloudy, rain and snow have to be opened, it is best to use light transmittance High drip-free or dust-proof membranes often keep the membrane surface clean. The humidity in the control humidity booth is too high, the water content in the seedlings is too high, and the concentration of the cell fluid is too low, which is prone to frost damage. Due to the lower temperature in early spring and the weaker light, the humidity in the shed is too high to induce the disease. In this regard, nursery greenhouses must strictly control the number of watering and watering, when the humidity is too high to enhance ventilation. Ventilation should be carried out at high temperatures around noon to prevent cold winds from blowing directly onto the seedlings to cause freezing damage. Strengthen the coverage of the night outside the shed should cover quilts, straw and other insulation materials, and keep the cover is often in a dry state, the interior of the shed should be hung with two layers of film, buckle small arches and other multi-layer covering insulation. In the north of the greenhouse, straw can be used as a windbreak to block wind and cold. Scientific fertilization does not apply nitrogen fertilizer to avoid reducing the cold resistance of seedlings. Potassium fertilizer can increase the cold resistance of seedlings. The application of sweet and sour liquid to the seedlings can increase the sugar content and hardness of the leaf meat, and can also improve the cold resistance. Full Body Protection Suit,Disposable Protective Clothing,Industrial Protective Clothing,Disposable Protective Coveralls Ningbo Autrends Prevention Products Co., Ltd , https://www.autrendsafety.com