How do greenhouse vegetables cope with abnormal weather in winter?

Snow, cloudy day, strong wind, long cloudy day and sunny day are common, which have great influence on the growth, yield and benefit of tomatoes in protected areas.

(1) Emergency measures for snowfall: Immediately after the snow stops, roll up the draft curtain and clear the snow on the shed film. For the parts that are difficult to clean in the middle slope of the greenhouse, gently scrape them off with a smooth wooden stick, and try not to cut the greenhouse film. When it snows at night, we should pay more attention to clear the snow on the straw curtain in time, and wrap the straw curtain with plastic film in advance to prevent the straw curtain from absorbing water, causing the shed body to be overweight, and the arch frame to distort or even collapse.

(2) Even the emergency measures on cloudy days should be treated differently. If it is cloudy, as long as the temperature is not very low, open the straw curtain. If you are exposed to the sun for a short time, the indoor temperature will rise. Hanging a reflective curtain on the back wall of the greenhouse will also add luster and harmony on cloudy days.

The role of warming. When there are many cloudy days in winter, plastic film should be covered as early as possible, which can improve the ground temperature and reduce the occurrence of low temperature freezing injury.

(3) Defending against windy weather When the greenhouse film bulges, it is necessary to immediately fasten the film pressing line or put down some grass curtains and press them in the middle of the roof in front of the greenhouse. In case of strong wind at night, it is best to cover the front foot of the greenhouse with a layer of grass curtain and press it firmly with stones.

(4) Management After a long period of cloudy and foggy weather, once it is sunny, the transpiration of tomatoes will be strengthened, and the absorption of roots will not keep up, and a large number of seedlings will die after sunny days. Its countermeasures: First, pay attention to covering the grass curtain to prevent seedlings from flashing. After clearing up, the temperature will rise rapidly and the seedlings will wither sharply. From about 10 in the morning, pay attention to the changes of seedling conditions and take appropriate measures such as covering grass curtains and spraying clear water (or foliar fertilizer) into the shed. Second, after a sunny day, water it as slowly as possible. You must rejuvenate the roots before watering them, otherwise it will easily lead to dead seedlings. If it is necessary to water topdressing, it should be watered with small water, and the quick-acting fertilizer should be applied with small concentration of water. Thirdly, after sunny days, irrigate the roots with root promoter and spray multi-element micro-fertilizer on the leaves to make up for the lack of root absorption.