What should I do after the fruit trees are damaged by low temperature freezing?

Recently, many planting friends sent pictures to consult diseases, including citrus, kiwi fruit and tomato. Open the picture and take a closer look. It's not a disease, it's a symptom of freezing injury caused by low temperature frost. Freeze injury can not be ignored, and it is harmful. Take precautions first, and then take remedial measures after freezing injury. . . Now the weather is getting colder and colder, and it is urgent to do a good job of antifreeze for fruit trees and vegetables.

First, the symptoms of crops after freezing:

1. Like burns, leaves lose their swelling pressure, tissues become soft, leaves turn brown, and finally dry up and die.

2. Sudden cooling makes the intercellular space and even the cell freeze, which increases the volume and damages the cell membrane, resulting in dehydration, mechanical damage and infiltration.

3. The inner tip of the branch is dead, and the bark of the base and stem is swollen and brown.

Second, how to prevent frostbite:

1. Covering rows of fruit trees with crop stalks and leaves or laying plastic films within one meter diameter around the fruit trees can not only preserve moisture, but also improve low temperature;

2. According to the characteristics that the roots and necks of fruit trees are easily frozen, soil the fruit trees 15cm, and peel them after spring.

3. Combine Qingyuan whitening trunk. Reduce the sharp change of temperature difference between day and night, avoid sun and rain, and freeze at night. When dry painting, the trunk should be painted all over until the main branch branches. It's best to brush white twice, the first time after falling leaves and before freezing, and the second time in early spring.

4. Spraying the leaves with Wofengsu, Kuifuling and brown sugar can not only kill the hidden bacteria source, clear the garden and repair the wound, but also prevent freezing injury, especially for subtropical evergreen fruit trees such as citrus and honey pomelo, which have no obvious dormancy period. Principle: Polysaccharides, peptides, chitosan and other polysaccharides in traditional Chinese medicine bactericides and warfarin can increase the content of soluble sugar in cells, thus lowering the freezing point. In addition, Wolfensohn also contains small molecular substances such as plant active glycosidic peptides, which can promote the synthesis of protein and energy, increase the concentration, viscosity and elasticity of protoplasm, and improve its cold resistance. )

5, the smoke is cold. When the weather forecast shows that the temperature drops, smoke will be ignited inside the greenhouse to form a smoke layer and keep the ground temperature. Open-air orchards use firewood, rice husk, chaff, sawdust, dead leaves, etc. As fuel (pay attention to control the fire), cover the fire and smoke, let the smoke cover the whole garden, cover the whole garden.

6. Irrigation with winter water. Irrigation before soil freezing after dormancy can promote trees to release latent heat and condensation heat of soil moisture, improve the cold resistance of fruit trees and ensure the safe overwintering of fruit trees. After thawing in the second year, the temperature was slow and the soil was loose and breathable. Irrigation before germination can reduce the ground temperature, delay the germination time and prevent the occurrence of late spring cold.

7. Brushing your teeth with Kwai Fu Ling before and after germination in spring can effectively prevent the occurrence of late spring cold and various branch diseases.

Third, remedial measures for fruit trees after freezing:

1, the fresh air cools down. After the vegetables in the greenhouse are frozen, the greenhouse cannot be closed immediately to raise the temperature, only the air can be cooled down, so that the temperature in the greenhouse can be slowly raised to avoid a sharp rise in temperature, and the protoplasm may be torn and damaged before it can absorb water and expand.

2. Water insulation. Irrigation can increase soil heat capacity, prevent low temperature drop, stabilize near-surface atmospheric temperature, help the temperature rise steadily, and restore the function of frozen tissue.

3. Dry with brown sugar+Wofengsu+Quifolin leaves, which can be compounded with other plant growth regulators. Using Chinese herbal medicine preparation to repair conduction function, quickly replenish nutrients for cells, control the spread of dead branches and grow new branches in the coming year.

Brushing and drying should use Chinese herbal medicine preparations with the function of combining medicine with tonic and nutrients containing high-energy substances such as fulvic acid, brassinolide, polysaccharide (brown sugar) and trace elements such as calcium, magnesium, zinc and boron. After the bark is absorbed, it can supplement various nutrient elements, increase nutrient reserves, sterilize and disinfect, repair wounds, relieve physiological diseases, prevent infectious diseases and restore tree vigor. The brushing time should be between half a month and one month before germination. The brushing height depends on the characteristics and damage degree of different crops. For example, the apple tree should be one meter long, and the key brush should be above the joint and at the bifurcation of the main branch, and the kiwifruit should be dried. The concentration of brush drying depends on the needs of disease control. Because the above Chinese herbal medicine preparations and various nutrients are compatible with crops, there is no phytotoxicity problem, and the limit is the stock solution, which can be diluted to 5-30 times, and the effect is better when silicone is added.