What are the technical measures for preventing cold and freezing of crops in winter?

Generally speaking, crops are not very cold-resistant, and they are easy to suffer frost damage in cold winter, causing economic losses to farmers, so what are the technical measures for preventing cold and freezing of crops in winter?

I. Technical measures for cold prevention and disaster reduction of vegetables

(1) strengthening the greenhouse, removing snow and preventing collapse

In recent years, greenhouse cultivation has developed rapidly, but bamboo-wood frame greenhouse is still the main body. According to the skeleton quality of each greenhouse, the greenhouse should be strengthened to improve the anti-pressure ability. When ice and snow comes, snow should be swept away from the roof.

(2) according to the situation, do a good job in the management and disposal of garden vegetables stored in the open field.

1. Lettuce with expanded stalk and cauliflower that have basically been picked should be put on the market as soon as possible (frost injury at-1 ℃).

two。 For the budding cauliflower, cover the bud with an old leaf, and then bind the outer leaves into bundles.

3. Cold-resistant vegetables such as lettuce seedlings, spinach, coriander, cabbage and other cold-tolerant vegetables were sprayed 2-3 times in cloudy or sunny days.

4. Radish should be strengthened to cultivate soil.

5. Qualified producers can cover vegetables with film or sunshade net to prevent freezing.

(3) strengthen the management of garden dishes in greenhouse memory.

The garden vegetables stored in the greenhouse are mainly cold-tolerant varieties of autumn and winter vegetables, and the following measures are recommended for management.

1. On a sunny and cloudy day, open the door of the greenhouse and give priority to reducing humidity.

two。 In rainy and snowy days, close the door of the greenhouse and keep warm.

3. At night, close the door of the greenhouse and keep warm.

4. Disease prevention and control: the main diseases are gray mold and early blight, and only aphids and whitefly are pests. Choose sunny or cloudy morning, spray dipropiconazole (propiconazole), Sukeling (Pythium) and other agents to control diseases; spray imidacloprid or Beauveria bassiana to control aphids or 1: 1 Bacillus thuringiensis to control aphids or whitefly.

(4) carefully deal with the cultivation of overwintering seedlings of eggplant and fruit vegetables. The following management measures are recommended:

1. The greenhouse must be covered strictly at night, and the greenhouse should be covered with a small arch shed film, but the small shed should open a vent every 10 meters on both sides, which is beneficial to dehumidification and disease prevention.

two。 When the temperature in the greenhouse is higher than 5 ℃, the greenhouse film will be opened throughout the day; when the temperature in the greenhouse is higher than 15 ℃, the two doors of the greenhouse will be opened for ventilation; when the temperature in the greenhouse is 0 ℃ ~ 4 ℃, the greenhouse film will be uncovered for 1-3 hours at noon.

3. When the temperature is below 0 ℃, choose to uncover the greenhouse film at noon for 30 minutes to 1 hour during the day, and close the greenhouse film for the rest of the time, but the vents on both sides should be opened.

4. When the temperature is below 0 ℃, qualified producers can set up air heating lines in the small arch shed, each 1-2 meters wide and 30 meters long seedbeds, using a 1000W air heating line, heating 5-10 hours (every day and night). If the ground hotline has been laid, the ground hotline is turned on and heated.

5. Clear the snow in the shed and drain the water around the greenhouse in time to prevent the snow water from seeping into the seedbed.

II. Technical measures for cold prevention and disaster reduction of citrus

1. Timely rescue of frozen cracked branches. The snow on the tree melts behind, quickly help the torn trunk back to the original growth site, bind the crack with a rope, and then wrap it with a film belt about 2 centimeters wide.

two。 Smoke cover according to the situation. In order to prevent the snow from getting worse, at 5-8 o'clock in the morning or at night, smoke piles were made of orange branches, fallen leaves, sawdust, crop stalks, etc., and set up 2-3 piles per mu of orange orchard to make smoke permeate the orange orchard and reduce freezing injury. For newly planted young trees, it is best to cover the crown with film or straw to increase the temperature in the canopy.

3. Timely classification and pruning. 7-10 days after snow, the dead branches were classified and pruned when the dead branches were easily identified by frostbite, and the dead branches, disease and insect branches were cut off, and the surviving branches and residual leaves were preserved as far as possible. It can be pruned in stages that are indistinguishable for the time being. When trimming, the cut should be smooth, and the big cut should be smeared with protective agents such as stone-sulfur mixture to reduce water evaporation.

4. Timely fertilization to promote spring shoots. After freezing injury, it is necessary to loosen the soil and apply fertilizer in time, applying 50-100 grams of urea per plant, once every 7-10 days, and 3-5 times in succession, in order to promote new shoots and restore tree potential.

5. Strengthen the prevention and control of diseases and pests. After citrus freezing injury, great attention should be paid to the prevention and control of resin disease, sunburn disease and leaf moth. Once the disease occurs, you should immediately row the tree trunk and smear the cracks with 100-fold topiramate or carbendazim solution. After the spring shoots are pulled out, the occurrence of leaf miner moths and other pests should be controlled in time.

III. Technical measures for Cold Prevention and disaster reduction of Tea

(1) Young and adult tea gardens.

1. For classified pruning. For young tea trees without picking noodles, different pruning methods should be adopted according to the degree of freezing. Those who are lightly frozen can generally not be cut and let them germinate naturally; for those who are heavily frozen, the frozen branches will be re-pruned separately with pruning shears in appropriate positions; if the freezing is very serious, the completely frozen branches will be cut off by table cutting, and only the frozen parts of the branches that are not completely frozen can be cut off, so as to facilitate the rapid recovery of tea tree growth. For adult tea trees that have been picked, different pruning methods should be adopted according to the degree of freezing. The light frozen ones should be trimmed on the fluffy surface, and the "shallow rather than deep" must be mastered when pruning to avoid cutting off part of the bud heads that can still sprout; for those with heavy freezing, re-pruning should be carried out in an appropriate position; if the frozen ones are very serious, table cutting can be carried out.

two。 Carry on the classified cultivation tube. The tea seedlings just transplanted in autumn of that year are easily arched by the whole permafrost because the root system has not yet fully recovered, resulting in a gap between the root system and the soil, resulting in the death of the whole plant. After the soil is thawed, step on the soil at the root of the seedling in time, make the root close to the soil, cover it with fertilizer or hay, and sprinkle some soil on it so as not to be damaged again. For young and adult tea gardens, shallow ploughing and weeding should be carried out after rejuvenation, combined with the application of some available nitrogen fertilizer (such as urea) and phosphorus and potassium fertilizer, especially young tea trees, the application of phosphorus fertilizer is beneficial to the growth of roots. In this way, it can not only supplement nutrients in time, but also play the role of promoting budding fertilizer, which plays a good role in restoring vitality and enhancing the growth of buds and leaves.

(2) breeding of improved varieties and seedlings.

1. Remove snow and protect the shed in time. As long as the weather turns warm, all localities should organize labor to remove the snow from the shed surface and fields in time, and immediately correct the collapsed arch shed to reduce the pressure time of the seedlings.

two。 Timely dredging and drainage. In the process of melting snow and ice, it is necessary to dredge the box ditch, the surrounding ditch and the main ditch in time, so that the ditches are connected, and the stay time of snow water in the seedling bed is reduced as much as possible.

3. Do a good job of smoke coverage. When the snow turns sunny, there is usually a strong frost, which does great damage to the seedlings. All localities should cover the arch shed with plastic or straw to prevent frost, and at the same time, 3-5 mu of weeds can be used to smoke in the evening to reduce frost damage.

4. Timely prevention and control of diseases. After the tea seedlings are frozen, they are often vulnerable to diseases. After the ice and snow have melted in a sunny day, Bordeaux liquid or carbendazim should be sprayed to control the disease.

IV. Technical measures for cold prevention and disaster reduction of rape

1. Clean up the "three ditches". Dredge the "three ditches" in time after snow and ice, drain waterlogging in the field, improve soil permeability, reduce the double effects of freezing and waterlogging on rape, and promote the restorative growth of roots.

two。 Remove frozen moss and frozen leaves in time. The early moss, leaves and yellow and white withered leaves injured by freezing should be removed and taken out of the field in time after the weather cleared, so as to promote the growth of basal branches and make up for the loss of freezing injury.

3. Topdressing quick-acting fertilizer. After the rape suffered frost injury, the leaves and roots will be damaged to varying degrees, according to the seedling condition, appropriate topdressing, supplement nutrients, promote the recovery of growth as soon as possible, topdressing 3-5 kg urea or 10 kg compound fertilizer per mu. Combined with the application of 100 grams of potassium dihydrogen phosphate and 50 kg of water spray, the field with poor growth can be appropriately increased.

4. Timely prevention and control of diseases. After freezing, rape plants are damaged and diseases such as Sclerotinia sclerotiorum are easy to occur. Sclerotinia sclerotiorum or prochloraz should be sprayed in time to control.

V. Protective measures for raising seedlings in greenhouse

1. Sweep the snow in time

two。 Reinforcement in the greenhouse

3. Close the shed doors at both ends

4. Take heating measures in the shed.