How to avoid Frost injury by planting Plum trees

Frost damage and freezing injury refer to the phenomenon that the temperature of soil and plant surface drops to 0oC or below for a short time at night during the growth period of fruit trees or encounters frost, resulting in damage to the tender parts of fruit trees. The average frost damage area in China is 340,000 km2 every year, and the heaviest year is 770,000 km2. The annual loss of crops, fruit trees and vegetables is 3 billion yuan. Especially in recent years, the late frost damage in northern China is particularly serious. Some fruit trees flowering early in spring often encounter late frost damage, with light yield reduction and severe harvest failure. Late frost damage has become a limiting factor for fruit tree development in some areas.

In order to effectively prevent late frost damage in the future, I would like to give you a few suggestions for your reference and other friends:

I. Relationship between orchard topography and frost injury

According to the investigation of fruit trees damaged by frost in Qixia, Penglai, Zhaoyuan, Laiyang, Haiyang and Muping counties (districts), the severity of late frost damage is related to the site conditions and topography of orchards. Because of the large heat capacity of water, a large amount of heat absorbed during the day is released at night, which can slow down the impact of sudden changes in temperature. Therefore, the fruit trees around the water source within the range of about 10km along the coast are less damaged, followed by the mountain tops and wind outlets with large air flow and frequent gas exchange and orchards with high terrain. The hardest hit are flat, dry riverbeds and low-lying flats, which are caused by cold air condensation in low-lying areas. In the investigation, it was found that the fruit setting rate of the branches above the water pool and the medicine pool was extremely high in the frozen orchard, and there was almost no effect on the yield. In the same orchard, the disk with weak tree vigor was more severely damaged than the orchard with strong tree vigor, the beach orchard was severely damaged, and the sticky soil orchard was relatively lightly damaged.

II. Relationship between tree rows and frost injury

Apple, pear, apricot and other fruit trees, crown lower heavy, upper light. The results of investigation in Qixia, Penglai, Longkou and Zhaoyuan showed that the flowers and fruits were seriously frozen mainly below 1.6 m above the ground, and basically not frozen above 2m. The natural open-heart shape of peach trees was seriously frozen, and the spindle shape was slightly damaged. The inner bore and lower young fruits of young peach trees were seriously frozen, and the young fruits of mature peach trees were slightly frozen.

III. Management measures and late frost damage

Through large-scale experimental demonstration investigation, it was found that the orchard under the same site condition had different damage degree due to different management level and different tree vigor. After using "Tianda-2116", one is to show freezing and cold resistance, the germination rate of frozen branches and buds is high, and there is obvious freezing and cold resistance effect. Second, the fruit setting rate is high, the fruit setting is uniform and tidy, the fruit stalk is long, the ear is long, and the fruit stalk is one third larger than that without spraying the ear. The investigation showed that the orchards with higher soil moisture were less damaged by freezing water before spring and pre-flowering water in spring, while the orchards without freezing water and pre-flowering water were more seriously damaged.

4. Remedial measures after fruit tree freezing

In order to minimize the losses caused by frost to fruit tree production, a series of preventive and remedial measures are proposed according to the specific conditions of different fruit trees affected by frost:

1. Use technology to avoid freezing damage

The damage of freezing injury to plants is mainly due to the destruction of membrane structure in cells on the one hand, and metabolism disorder caused by membrane destruction on the other hand. Because the concentration of aqueous solution in cell space is lower than that in cell fluid, it causes water leakage in cells. After spraying "Tianda-2116", it can effectively reduce the exudation of cytoplasmic fluid, maintain water content and protect cells. Even if freezing injury occurs, it can repair the membrane system of cells in time, thus achieving the purpose of preventing freezing injury. Practice proves that Tianda-2116, a key product popularized by the state "863 plan", can effectively resist the damage of stress factors such as freezing injury. Dried with "Tianda-2116" can promote the growth of damaged fruit trees and reduce the losses caused by freezing injury. In addition, while using science and technology, we must first choose the site of the garden, generally low-lying land, closed valley easy to accumulate cold air, easy to suffer from freezing damage; and in the hills, sunny slope and reservoir around the tree, air circulation, low probability of freezing damage.

2. Irrigation

Irrigation or sprinkler irrigation at the beginning of germination in spring can significantly reduce the ground temperature and delay germination, and irrigation 1~2 times before flowering after germination can delay flowering for 2~3 days. Irrigation or sprinkler irrigation before freezing injury can increase soil temperature and tree temperature, prevent and reduce freezing injury.

3, painted white

Painting white on early spring trees can effectively prevent sunburn, delay bud flowering for 3~5 days, paint white not only can prevent freezing, but also can effectively prevent pests and diseases. (Formula: 10 parts of quicklime, 1 - 2 parts of salt, 35 - 40 parts of flour)

After all, flower and bud have stronger ability to resist freezing injury than young fruit.

4. Strengthen management and strengthen tree vigor

Frost damages young fruits, shoots and leaves of fruit trees to different degrees. In order to restore tree vigor as soon as possible, fertilizer and water management should be strengthened, tree nutrition should be supplemented, the cell sap concentration of fruit should be improved, the drought resistance and disease resistance of tree vigor should be enhanced, more fertilizer should be applied before and after flowering, compound fertilizer such as special fertilizer for fruit trees should be applied, and "Tianda-2116" should be sprayed together."Tianda-2116" 600 times should be sprayed once every seven days for repair and remedy. Spraying twice continuously to restore tree vigor. Increase fruit set rate and single fruit weight to ensure a good harvest in disaster years. In particular, we should do a good job of foliar fertilizer. Fertilizer should choose high-quality liquid fertilizer, such as 0.3% potassium dihydrogen phosphate solution or 0.3~0.5 urea solution.

5. Pharmaceutical protection

After the tree body is frozen, the tree vigor is weak, the disease resistance ability is reduced, and it is easy to cause pests and diseases. To timely spray methyl thiophane, Polygon, triadimefon or carbendazim, etc., to control powdery mildew, leaf spot disease and other pathogen infection and pest damage. It can also be sprayed in the afternoon or evening of the day when the frost injury comes. Such as "Tianda-2116", which contains a large number of molecular chain active substances, after spraying on the surface of the tree to form a layer of molecular membrane, and a variety of trace elements inside can improve the concentration of cytoplasm, can effectively activate the chitinase and protease in the crop body, greatly improve the content of amino acids and chitin, increase the content of unsaturated fatty acids in the cell membrane, reduce the freezing point of the cell, so that it can grow normally at low temperature.

6. Reasonable trimming and retraction

Do not prune or remove the damaged branches, leaves and fruits of all trees and varieties in a short time. The method of late thinning and keeping more fruits should be adopted to retain the fruits that are not damaged or lightly damaged, so as to ensure more fruits and good fruits and recover the losses caused by frost. At the same time, the branches and corners of the tree should be pulled to control the vegetative growth and let it recover naturally. In the middle of May, the branches that are harmful to frost and cannot be recovered should be cut off or retracted to the healthy parts in time to promote their re-germination and sprouting; the frozen branches and buds should be wiped out to promote the hidden buds to make up for the lack of yield. Old and inferior varieties yield no garden, can take the spring hard branch grafting or green branch grafting method for high-quality varieties to graft. It is necessary to do a good job in pruning orchard growth season, regulate nutrition distribution, and ensure the needs of fruit growth and flower bud formation.

7, smoking

Fumigation is a common way for fruit growers to deal with frost damage. The prevention effect depends on the quality of tobacco, and the orchard temperature of high quality is about 2℃. At least 5~6 piles of raw smoke are distributed evenly in each direction. The hay pile is 1.5 meters high and the bottom diameter is 1.5~1.7 meters. When stacking grass, insert several thick wood rollers directly and obliquely. After stacking, extract them for ventilation holes. Place inflammable substance inside straw pile through hole, and cover straw pile with wet grass or wet mud. This smoke is sufficient and lasts for a long time. Smoke can be used crop straw, weeds, leaves and other flammable materials that can produce a lot of smoke. Fumigation has certain effect on slight freezing injury above-2℃, but the effect is not obvious below-2℃.

Today, some places serious environmental damage, a variety of natural disasters occur frequently, so fruit farmers can not be taken lightly, to prepare for a rainy day, watch the weather forecast, do emergency measures in advance. Say a thousand ways ten thousand, strong trees to resist the ability to freeze naturally strong, just as strong people freeze, weak people afraid of cold. However, if the temperature is really low, the above methods will not work well.