How to control the wilting of vegetables when the temperature rises after snow

After heavy snow or continuous low temperature few days in winter, when the temperature rises rapidly, vegetables in the greenhouse will often wilt. If they can not be quickly identified and targeted measures can not be taken, the growth and development of the light will be delayed and the serious will die. The causes and countermeasures of vegetable wilting after snow are summarized as follows:

Wilting of vegetables in greenhouse

1. Physiological and temporary wilting. It's more common. One is long-term low temperature and low light, and the soil and air humidity in the greenhouse is high, which makes the root system underdeveloped. on the other hand, the temperature in the greenhouse rises rapidly and the foliar transpiration increases, but the soil temperature rises slowly and the root activity of vegetables is low.

Countermeasures: when the outside world heats up quickly, we should pay attention to the changes of vegetables, find that vegetables wilt, cover or partially shade, reduce transpiration, and then reveal after recovery. After 2-3 days of exercise, it can be transferred to normal management. In addition, do not pour water, you can properly spray foliar fertilizer to promote growth.

2. Low temperature freezing injury. Due to the low temperature in the early stage, part of the leaves or the edge of the leaves were frozen and lost the function of water retention. At the initial stage of the damage, the leaves or shoots are immersed in water, which will soon dry up and turn green. Breakage of tuyere or cover film is easy to occur.

Countermeasures: (1) reasonable topdressing. Spraying foliar fertilizer on frozen vegetables can not only improve the nutritional status, but also increase the concentration of cell tissue fluid, enhance the cold resistance and freeze resistance of vegetables, and promote the recovery of growth. Melons and eggplant vegetables, use three-element compound fertilizer; leafy vegetables, spray 1-2% urea aqueous solution, add green protection. Root vegetables, sprayed with 0.3% potassium dioxin phosphate plus green protection. Foliar fertilizer should be sprayed evenly and thoughtfully, and both sides of the leaves are covered with liquid fertilizer. 7-10 days after spraying, spray again.

(2) watering in time. After the occurrence of frost injury, it is necessary to water in time, increase soil heat capacity and restrain the decrease of ground temperature, which can effectively reduce and control the frost injury. Choose groundwater for watering, not use water. Watering water to reach the plough layer is appropriate, do not flood irrigation.

(3) Scientific ventilation. After the occurrence of frost injury, the shed can not be closed immediately, if the temperature is too fast, the frozen tissue of vegetables will be dehydrated to death. After the sun comes out, the vents should be opened moderately, and after a period of time, the vents will be gradually reduced and closed. Let the greenhouse temperature rise slowly, so that the frozen tissue of vegetables can fully absorb water, promote cell resurrection and reduce tissue death.

3. Harm of diseases and insect pests. In the early stage, the root or stem base of vegetables was damaged by root rot, Fusarium wilt, bacterial wilt or underground pests. Check the root and stem, you can find lesions or insect bite marks.

Countermeasures: take partial shading, reduce transpiration, prevent water shortage of vegetables, and control diseases and insect pests found.

In short, the wilting phenomenon of vegetables in winter should be clearly identified and correct measures should be taken to avoid unnecessary losses.