The causes of casualties of fruit trees in winter and protective measures

The northern region has more sunny days in winter and spring, less rainfall, air drying, and low temperatures, and can easily cause frost damage in fruit trees. Especially in the early winter and early spring, the climate is characterized by dry and windy conditions, little rain, and a large temperature difference between day and night, which can easily lead to fruit stripping and freezing injury, and seriously affect fruit tree production. To this end, special apples and pears are taken as examples to analyze the causes and introduce preventive measures as follows:

I. Causes of winter and winter deaths of apples and pears

1. Abnormal climate change, which is the direct cause of the winter deaths and injuries of fruit trees. For example, the sudden fall in early autumn temperatures and rapid changes in day and night temperatures can easily cause frost damage in fruit trees. After the beginning of spring, temperatures gradually rise, and the dormancy periods of apples and pears are gradually relieved. Sexuality is also rapidly weakening, and it is excellent for flowering and fruiting. At this time, fruit trees are extremely sensitive to the reflection of low temperature, and their ability to resist cold is extremely weak. In case of a low temperature below -2°C and a duration of more than half an hour, freezing damage can occur.

2, varieties of cold-resistant weak apples such as India, green bananas, Fuji, pear in the pear, Dangshan pear, etc., poor cold resistance, prone to frost damage.

3, weak tree vigor or tree growth is not full According to the survey, weak trees, small trees are poor cold resistance, vulnerable to freezing damage; tree growth is too prosperous, the late autumn to stop the growth of late trees, branches are not substantial, and the formation of protection Underdeveloped organizations are also prone to frost damage.

4. Other trees that suffer from mechanical damage and serious pest damage have poor cold resistance and can easily cause winter casualties.

Second, protective measures

1. To create orchard shelterbelts To build orchard shelterbelts is a good protection measure against freezing damage of fruit trees. According to investigations, protective forests in orchards can increase the temperature within the park by 2–5°C. Therefore, the establishment of orchard protection forests can well alleviate the occurrence of frost damage in fruit trees. Orchard shelterbelts often use tightly structured forest belts formed by arbors and shrubs, which provides good protection.

2. Select apples varieties that are suitable for local terroir conditions and strong cold resistance such as marshals, Guoguang, sweet yellow kuwait, etc.; pear varieties such as pear, snow pear and other varieties have strong cold resistance.

3. Water content in advance watering soil is high, so that the heat capacity and thermal conductivity of the soil are also increased, so that the daytime temperature in the soil is low and the nighttime temperature is high. Therefore, watering before the low temperature can prevent and mitigate the damage of frost.

4. Strengthen the tree vigor and make the growth of branch shoots adopt the “fettering and restraining the strong” measures to manage the trees. For weak trees, strengthen the supply of fertilizer and water in the early stage of growth, increase nitrogen fertilizer, strengthen the cultivating soil, fully meet the tree's need for water and nutrients, and make the fruit trees grow well; the late growth period of fruit trees (from August to October) , Stop irrigation, use less nitrogen fertilizer, pay attention to the application of phosphorus, potash and farmyard fertilizers, such as foliar spraying of 0.2%-0.3% of potassium dihydrogen phosphate or ash leaching, and take measures to control the prosperous growth of trees. Long, such as spraying 700-800 mg / liter of paclobutrazol or chlormequat 1-2 times, for the prosperous shoots to take a continuous topping or twist tip, press branches and other measures to control prosperous, promote fruit tree mature aging, strengthen the tree Accumulation of nutrients increases tree protection and cold resistance.

5, to strengthen the prevention and control of pests and diseases, timely protection of the wound growth season in a timely manner to do a good job of tree pest control work, it is the late growth of the tree, pay attention to the control of Daphnia vulgaris, early defoliation. For the wounds caused by mechanical damage or pest damage and pruning, etc., waxing, bandaging, etc. should be processed in time to reduce tree water loss or pest infestation and affect the normal physiological activities of the tree.

6. When the orchard smoke is predicted to have frost, one evening before the frost, piles of grass piled up alternately from wheat straw, weeds, sawdust, or branches will be stacked at regular intervals in the orchard. Cover a layer of soil with a wooden stick in the middle to facilitate ignition. It causes a lot of smoke when it ignites. Smoke can reduce radiation emission of soil heat, while smoke particles absorb moisture, so that water vapor condenses into liquid and releases heat, raising the temperature.

7. Before the tree is wrapped around the grass or wrapped with plastic film to protect the tree from overwintering, use straw, wheat straw, etc. to make the main branch of the fruit tree and the big side branches tightly. The second year after the fruit is sprouted, remove the grass and burn it centrally. Not only does the tree safely pass through the winter, but it also attracts a large number of insects that infiltrate into the grass to overwinter, killing birds with two birds with one stone; it is also possible to use a plastic film to wind the main body and side branches of the tree and cover it under a tree plate to increase the temperature of the soil and reduce water evaporation. , improve the ability of the tree to resist cold and overwintering.

8, the antifreeze agent in the fruit bud before flowering 2-3 days before spraying the tree cold resistance plant. Or spray low concentration of ethephon or naphthalene acetic acid, fresh water solvent before budding of fruit trees to restrain buds sprouting and improve cold resistance. For the flowering tree, spraying 0.3% potassium dihydrogen phosphate plus 0.5% white sugar before low temperature comes, and spraying it 2-3 times, it can play an antifreeze effect. The fruit trees are painted white before they pass winter, and they have protection against cold and freezing when wintering the trees. Whitening agent formula: quicklime 5kg, sulfur powder 1-5kg, salt 2-3kg, vegetable oil 1-1.5kg, flour 2-3kg, water 15kg, lime and salt are respectively used for hot water Open, stir into a paste, then add sulphur powder, vegetable oil and flour, and finally add water to mix. Brushing the trunk and large lateral branches before wintering has a good antifreeze effect.

In addition, with weeds, leaves, manure and other materials before the onset of frost damage in the tree cover, thick 10-15 cm, can increase the ground temperature 3-5 °C, can play a role in antifreeze protection.

Third, the consequences of the tree after the care of the frozen When the fruit trees are frozen after the first should strengthen soil management, increase nitrogen fertilizer. For peeled and loosened cortex, nails should be nailed in place as soon as possible to maintain a certain degree of humidity in the layered cells. The part of the cortex that has been frozen to death is removable, and the bridging method is used to keep the nutrient transport free. In the xylem, where heavy freeze damage occurs, more nitrogen fertilizer should be applied to promote the growth of the formation layer and form new xylem and cortex. The frozen trees are best not to be pruned in the spring, but in the growing season, the flowers and fruit should be re-reduplicated to reduce the burden so as to restore the tree vigor. For leggy branches should be topping control, do not dredge, try to retain the leaf area.

Op seeds, heat and dry resistant Coriander Seeds, grow very fast, bright green leaf, light green petiole, up-right, great flavor, easy planting and wide adaptability, suit for growing in warmer weather, best grow temperature is 15 to 30 degree.
 
Purity   ≥85.0%
Neatness    â‰¥70.0%
Germination percentage     ≥85.0%  
Moisture      â‰¤10.0%
Origin      Ningxia, China

Sowing dosage: 1kg to 1.5kg per 667m2.
PH VALUE: Not special request

Coriander Seeds

Coriander Seeds,Organic Coriander Seeds,Dried Coriander Seeds,Raw Material Spice Coriander Seed

Ningxia Zhongqing Agricultural Technology Co. Ltd. , https://www.zq-vegetableseeds.com