The work of anti-freezing of fruit trees in winter can not be ignored.

The warm winter weather has occurred continuously in our province in the past three years, and the average temperature in winter is higher than that in normal years. Since the beginning of winter this year, the temperature is still on the high side, so it should be another warm winter. Warm winter will cause fruit trees to stop growing late and reduce their frost resistance. If they encounter a sudden sharp drop in temperature, they are extremely prone to frost damage. The majority of fruit farmers should not neglect the anti-freezing management of fruit trees because of the warm winter, causing losses to the production of fruit trees. In particular, more attention should be paid to the orchards in the following situations.

An orchard with newly planted young trees. The mature fruit trees with strong body are fully developed, have strong anti-freezing ability, and generally have less frost injury. On the other hand, because the newly planted young trees have the habit of vigorous growth, stop growing late, underdeveloped roots, poor branch development and poor frost resistance, they are prone to frost injury in case of low temperature, and affect the spring sprouting of branches after freezing injury, which is easy to cause dead trees.

Second, planting orchards of tree species or varieties with poor frost resistance. Different tree species and varieties have different resistance to frost injury. It is more necessary to do a good job in anti-freezing work for tree species and varieties that are prone to freezing damage. Such as pear, jujube and other tree species have strong cold resistance, and the possibility of freezing injury is small. While apple, peach, apricot, grape, walnut, cherry and other tree species have poor cold resistance and are prone to frost damage, especially some of these tree species with poor cold resistance should do a good job in preventing frost damage. Such as the Red Fuji in apples, the 21 century in peaches, Birthday Bun with Bean Paste Filling in China, most of the grape varieties and so on. Although pear trees are more resistant to low temperature, some varieties are prone to freezing injury, such as snow pear, golden pear, Huangguan pear, Yulu fragrant pear, etc. the flower buds are easy to freeze, produce stiff buds, cannot blossom normally in spring, affect fruit setting, and reduce yield. attention should be paid to it in production.

Third, orchards with low level of management and poor producing conditions. The occurrence of frost injury in leeward and sunny orchards was lighter, while that in overcast orchards, lowland orchards and sandy orchards was more serious. In the orchard with good management, the fruit load is reasonable, organic fertilizer is valued, chemical fertilizer is applied reasonably, the tree is strong, the storage nutrients are sufficient, the branches and buds are abundant, the cold resistance is strong, and the freezing injury is not easy to occur; on the contrary, in the orchard with too much fruit and too much nitrogen fertilizer, the new shoots are easy to grow, stop growing late, branch development is poor, tree body is flourishing, and freezing injury is easy to occur.

In view of the above situation, the following work should be done to prevent the occurrence of frost injury to fruit trees.

First, do a good job in summer management of fruit trees. First of all, the load should be reasonable to prevent the occurrence of undernutrition of the tree. Secondly, we should pay attention to the use of more organic fertilizer and less chemical fertilizer. At the same time, the combination of nitrogen, phosphorus and potassium is reasonable, and the proportion of nitrogen fertilizer used in the whole year is about 1 ∶ 0.5 ∶ 1. The amount of nitrogen fertilizer must be controlled in the later growth stage to make the tree healthy, stop growing in time after winter, enrich the branches and improve the ability of frost resistance.

Second, spraying phosphorus and potash fertilizer. In October, the tree is still in the growing period, so the fruit trees can be sprayed with phosphorus and potassium fertilizer, and trace elements can be added conditionally to promote the development and enrichment of branches and flower buds, and improve the frost resistance of trees and flower buds. If you can spray 3/1000 of potassium dihydrogen phosphate solution. Spray once every 5-7 days, twice in a row.

Third, pour enough frozen water. Winter irrigation should be carried out on the orchard before the beginning of winter, on the one hand, to enhance the frost resistance of the tree, on the other hand, the characteristics of high specific heat of water can be used to enhance the buffer capacity of the orchard to the change of air temperature. At the same time, it can prevent spring drought in the coming year.

Fourth, the trunk is painted white. It is necessary to whiten the trunk of those tree species, varieties or poorly managed orchards that are prone to freezing injury, mainly on the trunk, main branches and big branches, which has a good effect on preventing frost injury.

Fifth, the orchard is covered. In winter, the orchard tree plate is covered with crop straw and green manure, generally covering 10 to 20 centimeters. Or cover it with plastic film. This can effectively increase the ground temperature and prevent the occurrence of frost injury of fruit trees. At the same time, we should prevent the straw from catching fire.

Sixth, focus on protection. Special protection should be given to some tree species and varieties whose frost resistance is obviously insufficient. For example, the fruit growers planting Birthday Bun with Bean Paste Filling of China should wrap the trunk and trunk of about 1 meter above ground with corn straw before winter, and then release it in spring.

7. Reasonable pruning. Do not trim too heavy, so that the tree to ensure a suitable number of branches, conducive to frost resistance. Paint the larger shears and saws in time to prevent the loss of too much moisture and weaken the cold resistance. If the number of flowers left is large, it can be re-cut before flowering in the spring of the following year.

Eighth, it is not advisable to scrape the bark too early. Scraping bark can remove most of the overwintering diseases and insect pests in the bark cracks, reduce the occurrence of diseases and insect pests in the coming year, and promote tree metabolism, which is conducive to the normal development of fruit trees. This technology is often used by tree species such as apples and pears. However, scraping the bark prematurely scrapes off the old tissue with strong anti-freezing ability in the outer layer, exposing the tender tissue in the inner layer, it is easy to produce frost injury, which leads to the weakening of the tree rest and affects the normal growth and fruit of the tree. Therefore, the work of scraping bark should be postponed appropriately, and the time can be controlled from late February to early March next year. And scrape the bark to be careful not to be too heavy, generally master the bark to show white.

9. Smoke the orchard and remove the snow if necessary. For some varieties with poor cold resistance, the orchard should be smoked when there is a big cold current to improve the microclimate temperature of the orchard. After heavy snow, it is necessary to remove snow from the trees before melting snow to prevent freezing damage to fruit trees due to snow loss and cooling.