Winter is the dormant period of apple trees, and the focus of orchard management is pruning in winter, combining with pruning in winter to cut off diseased branches and insect branches, scraping off coarse old bark, and reducing or eliminating overwintering pests and diseases.

First, the pruning of small trees

1. Young trees should be pruned according to the principle of "giving priority to lightness, paying equal attention to modeling and results, and promoting early yield increase". On the premise of arranging the main branches, the key point of pruning is to clean up a dense layer of branches and straighten the tree. According to the planting density, the small crown sparse layer shape (less than 80 plants per mu) and free spinning cocoon shape (more than 80 plants per mu) can be popularized.

2. Sparse layer shape of small crown: select 3-4 main branches in the first layer, and clean up the dense branches that affect the growth of main branches after selection, and clean up 1-2 branches every year, and strive to clean them up in 2 years.

3. Free rotation: choose 3~4 small main branches every year, with the spacing of main branches about 20 cm, and properly drain the branches that are too dense.

Second, the pruning of the first fruit tree

Young trees of 5~8 years old have entered the fruiting period, and the key point of pruning is to clean up the dense branches between layers, improve the lighting conditions of the trees, and make the fruiting parts gradually transition to the backbone branches. Clean up 2~3 crowded places every year, and strive to clean them up in 3 years. After several years of adjustment and cleaning, five main branches, 1~2 auxiliary branches and 10~ 13 main branches were retained in the sparse layer.

Third, pruning of mature trees.

1. Pruning of adult trees: With the aim of "improving the light, improving the quality of branches, stabilizing the quality and increasing the yield", the key point of pruning is to remove more than two layers of large auxiliary branches, large lateral branches and large branch groups that are too dense in batches, so that the large branches remaining above two layers can extend outward like whips as much as possible, and the total number of branches accounts for less than 20% of the total number of branches of the whole tree, which is convenient for one layer of light.

If the crown of the tree is on the high side, it is necessary to gradually bow your head and be happy by the strength of the tree, and the height of the tree should be controlled below 3.5 meters; If the crown has crossed, the densely packed branches should be drained or transformed into small branches, and the branches should be shortened to slow down the outside and promote the inside, or the direction and angle of the main branches should be changed by changing the main branches, so that the crown distance should be kept at about 1 m to improve the lighting conditions of the population and individuals. "Trees can't bear fruit without light, and branches can't grow thick without light." Pay special attention to dimming when pruning, and resolutely sparse some big branches that affect the light, without mercy.

2. Balance of tree potential and branch potential: Unbalanced tree potential of fruit trees will lead to difficult fruit bearing. As the saying goes, "one side is strong and the other is weak, and both sides will not bear fruit." The strong side loves to plant trees, but the weak side does not see flowers. " Pay attention to the adjustment when pruning, and it is not allowed to be strong before and weak after, and strong above and weak below.

3. Master-slave relationship: the main branch is from 1/3 to 1/5, and the upper branch of the main branch should be from 1/5 to 1/7. Those larger than the main branches should be resolutely removed, leaving no future trouble.

4. Clever retraction: the branches are aging, and those without fruiting ability should be retracted and updated in time. Generally speaking, the result of not picking the auxiliary tip of the fruit table indicates aging.

5. Tree age: Pruning varies with tree age. Young trees grow vigorously, so they should be cut lightly and repaired more, and old trees should be renewed and rejuvenated.

Fourth, cut off diseased branches and insect branches.

According to the investigation, many diseases and insect pests that harm apples overwinter on the branches. For diseases and pests that overwinter in trees, combined with winter scissors, all branches of diseases and pests are cut off, burned or buried deeply, which can obviously reduce the harm in the coming year.

5. Scrape off the rough old bark.

A large number of overwintering bacteria and pests often lurk in the gaps between the thick old bark and trunk of fruit trees. Scraping rough old bark, burning or burying it deeply has a good control effect on many kinds of pests and diseases, and sometimes even completely eliminates some pests.