Quick look! Winter is here, 4 pesticide application techniques for greenhouse vegetables.

    1. Improve the thermal condition of the facilities and increase the temperature of the shed

    This work should be done right from the time the greenhouse is built. According to the latitude of each region, select the appropriate greenhouse height and the angle between the greenhouse film and the ground, and optimize the light and heat effect of the solar greenhouse as much as possible. The cover of the greenhouse must be effective and not improvised. If necessary, add a layer of grass curtains to the bottom corners of the sunny side at night or install a hot blast stove to increase the temperature in the shed at night. In addition, the surface of the greenhouse film must be cleaned frequently to increase the light transmittance.

    2. Grasp the sensitivity of varieties to temperature

    According to the medium and long-term weather forecast, choose the appropriate sowing date and planting date to carefully read the description of the variety planting conditions. Varieties that are not familiar with winter are best to be planted on a large area after the experiment. According to the local climatic conditions, choose the appropriate sowing and planting period. When encountering special weather, take cold-proof measures as much as possible to protect the vegetables from cold damage.

    3. Use variable temperature management when raising seedlings to strengthen the exercise of cold resistance

   During the seedling stage of fruits and vegetables, variable temperature management should be implemented according to the development requirements of the seedlings to cultivate strong seedlings. Generally, the temperature should be increased after sowing, and the temperature should be lowered after emergence to avoid excessive growth; the temperature should be raised again after seedling division to promote the growth of new roots; the temperature should be lowered before planting to improve the cold resistance of the plant. When cultivating tomato seedlings, when the plant is in the differentiation of flower buds (generally after two true leaves), the night temperature should be appropriately increased to keep the night temperature as close as possible to about 15°C to prevent the occurrence of deformed fruits.

Fourth, do a good job of temperature, moisture and nutrient management during vegetable growth

    It is necessary to control the temperature of the shed, and avoid excessively high shed room temperature when it is sunny, especially when the shed room temperature is too high, the wind should be slow to avoid sudden fluctuations in the room temperature. On cloudy days, it is necessary to appropriately shorten the time of uncovering the grass curtain, reduce the number of times of entering and leaving the greenhouse, and keep the temperature of the shed as much as possible. Avoid flooding the plants in the vigorous growth period with cold water when the temperature in the shed is high.

    When the plants wilt due to continuous cloudy days, generally do not water them. If the weather begins to improve and the soil is dry, when it is necessary to water, use a kettle to pour warm water and never flood it with cold water. Avoid the plants from being exposed to the sun during long periods of overcast weather. You can use the method of returning to thatch (or placing the thatch at intervals, or using a heat-preserving quilt) to avoid sudden high temperatures. When the cucumber has a flower topping, some young melons can be properly trimmed to facilitate the elongation of the branches. In addition, spraying high-efficiency foliar fertilizer to strengthen the growth of vegetables is also conducive to increasing the cold resistance of crops.