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Greenhouse how to prevent "fog" harm
Source：本站 Time：2020/3/10 13:42:37 frequency：
When the water vapor in the lower atmosphere reaches the saturation state, the condensation of water vapor will be suspended in the air to form fog. Foggy weather is often accompanied by low temperature, high humidity and little light, which is very unfavorable to the growth of greenhouse vegetables and easy to induce a variety of diseases and insect pests
1. Heat preservation, anti-freezing and fog should be appropriately added to cover, to prevent vegetables from freezing. In case of continuous cloudy and foggy weather, the covering should be properly removed late, and the temperature change should be observed after the lifting, if there is a slight drop, should be removed with the cover; With a slight recovery, the cover can be redone by 2 p.m. If the temperature in the greenhouse continues to drop, artificial heating should be carried out. After continuous cloudy, foggy days suddenly sunny, after removing the cover to observe the seedling changes, found wilting, immediately cover, after recovery, opened again, wilting cover again, so repeatedly, after 2-3 days, can be transferred to normal management; If opened regardless, easy to cause "inverted seedling".
2. Increase the light to keep the shed membrane clean and increase the light transmittance. Strengthen the management of greenhouse covering, by timely peel, timely cover, make full use of the scattered light of cloudy day, make the plant carry out photosynthesis. If necessary, you can also use a 40-watt fluorescent lamp three together, hanging 45 cm from the seedling, or a 100-watt high-pressure mercury lamp hanging 80 cm from the seedling artificial light,
3 control humidity greenhouse greenhouse vegetables from beginning to end to strictly control watering, especially in foggy days, generally do not water, to prevent root damage. If the greenhouse humidity is too large, to timely ventilation and wet; When not ventilated, can scatter in the line between grass and wood ash or fine dry soil hygroscopicity.
4. Scientific use of fog to prevent and control vegetable diseases and insect pests in greenhouse greenhouses, pay attention to the selection of symptomatic, pesticides, and try to use smoke or dust method of application; If spraying is used, try to reduce the frequency of prevention and treatment to reduce the humidity in the shed.
1. Heat preservation, anti-freezing and fog should be appropriately added to cover, to prevent vegetables from freezing. In case of continuous cloudy and foggy weather, the covering should be properly removed late, and the temperature change should be observed after the lifting, if there is a slight drop, should be removed with the cover; With a slight recovery, the cover can be redone by 2 p.m. If the temperature in the greenhouse continues to drop, artificial heating should be carried out. After continuous cloudy, foggy days suddenly sunny, after removing the cover to observe the seedling changes, found wilting, immediately cover, after recovery, opened again, wilting cover again, so repeatedly, after 2-3 days, can be transferred to normal management; If opened regardless, easy to cause "inverted seedling".
2. Increase the light to keep the shed membrane clean and increase the light transmittance. Strengthen the management of greenhouse covering, by timely peel, timely cover, make full use of the scattered light of cloudy day, make the plant carry out photosynthesis. If necessary, you can also use a 40-watt fluorescent lamp three together, hanging 45 cm from the seedling, or a 100-watt high-pressure mercury lamp hanging 80 cm from the seedling artificial light,
3 control humidity greenhouse greenhouse vegetables from beginning to end to strictly control watering, especially in foggy days, generally do not water, to prevent root damage. If the greenhouse humidity is too large, to timely ventilation and wet; When not ventilated, can scatter in the line between grass and wood ash or fine dry soil hygroscopicity.
4. Scientific use of fog to prevent and control vegetable diseases and insect pests in greenhouse greenhouses, pay attention to the selection of symptomatic, pesticides, and try to use smoke or dust method of application; If spraying is used, try to reduce the frequency of prevention and treatment to reduce the humidity in the shed.