Cultivate strong trees to enhance the ability of cold resistance and stress resistance

Controlling temperature, preventing prosperity and promoting strong trees now the shed has already been covered with grass grass, and the temperature at night has been guaranteed, but because it is covered with grass grass, the temperature is often not well controlled during the day. The suitable growth temperature of most vegetables is 25 ℃ ~ 30 ℃ in daytime and 13 ℃ ~ 18 ℃ at night. Therefore, under the premise of ensuring that the temperature of the greenhouse does not drop more than 2 ℃ after opening the grass, it is necessary to uncover the grass early. When the temperature of the shed reaches 28 ℃, the ventilation should not be too large, and the gap of 10 cm should be opened. When the greenhouse temperature is higher than 32 ℃ at noon, the vents should be enlarged to prevent the temperature from being too high and affect the normal development of vegetables. When the greenhouse temperature reaches 22 ℃ in the afternoon, close the vents and cover the grass grass to keep warm when the greenhouse temperature reaches 20 ℃.

Increase the light time and increase the light intensity

Because more than 90% of the yield of vegetables comes from photosynthates. Therefore, in the winter with short sunshine time, it is necessary to increase and replenish light to promote the operation of vegetable photosynthesis. Therefore, on the basis of selecting the drip-free film with good light transmittance and long life, the film is often cleaned to keep the greenhouse film with high light transmittance. In addition, under the premise that the temperature in the greenhouse does not decrease, uncover the grass and cover the grass as early as possible, so that the vegetables in the greenhouse can see more light early and more, so as to increase the accumulation of photosynthates. A reflective screen can also be hung on the north wall of the shed to improve the lighting condition in the shed.

Moderate water control but no water shortage although the temperature is low, the ground temperature is low, the growth rate of vegetables in the greenhouse is slow, and the demand for water is small, but it is not suitable to control water too much. Because the small water demand is relatively high temperature season, greenhouse vegetables generally need more water, if the normal supply of water can not be guaranteed, its normal growth will be seriously affected. When the plant growth is affected, the ability of disease resistance and stress resistance will be greatly weakened. Therefore, the key to water management is to coordinate the relationship between watering and increasing soil temperature and reducing humidity in the greenhouse, not only to ensure the normal demand of vegetables for soil water and nutrients, but also to maintain a suitable ground temperature, but also to reduce the humidity in the greenhouse as much as possible.

Irrigating fertilizer is not excessive, spraying foliar fertilizer at the right time

In the low temperature period, vegetables grow slowly and require less nutrition, and the application of chemical fertilizer is easy to cause root injury, yellow leaves and other problems. At present, flushing fertilizer should be mainly organic fertilizer or biological bacterial fertilizer, because the application of organic fertilizer or biological bacterial fertilizer can not only meet the nutritional needs of vegetables, but also increase the soil temperature, promote the rooting of vegetables, and expand the range of nutrients absorbed by roots. Fertilizer damage is not easy to occur. However, flushing fertilizer should not be excessive, generally applying 20 kilograms of organic fertilizer or biological fertilizer per mu each time. When the root activity is weak, foliar fertilization is a good way to supplement plant nutrition.