(1) relax the conditions and choose the main and side branches.
Pear trees have few branches and weak branching ability. In order to form the crown early, it is necessary to relax the conditions and choose the main branches and side branches. If you can't choose the three main branches at the base in that year, you can choose short branches or middle branches outside the main branches in the plastic belt, and you can't cut them short or thin them. When the second young tree grows vigorously, these short and medium branches can become long branches with wide angles, which can be used as the main branches of the first layer.
The order of the upper branches of the main branch should be flexible. In the case of missing edges, you can leave opposite branches, or you can use the back branches and use them by adjusting the direction; In order to promote the growth of lateral branches, medium and short branches with suitable direction can be cultivated and utilized; Or sparse inflorescences, promoting fruiting branches, as side branches; There are no side branches and there is no need to rush to cultivate the main branches. When the tree is big and the angle of the main branch is opened, it will naturally branch and can be used.
(2) Adjust the tree potential to avoid excessive differences in the backbone branches at all levels.
Pear top has a strong advantage and is easy to maintain its subordinate relationship, but it is often prone to the situation that the middle branch is too strong, which greatly exceeds the main branch or the growth gap between the main branch and the lateral branch is too large. In order to make its growth balanced, it must be adjusted by restraining the strong and helping the weak.
First, urge the strong to bear fruit early, and the fruit will press the branches; The extension branch can adopt weak branch and weak bud as the head; Properly thinning the upper branches and leaves; By changing the head, it bends and rises. Take the opposite measures against the weak.
Secondly, in order to prevent the middle branch from being too strong, several main branches of the first floor can be rotated or adjacent, and the first side is required to be slightly close to the main branch. You can also use the extended branch of the central branch as the main branch and replace it with a new branch or other weak branch. In order to weaken the growth of the main branch, the lateral branches can be opposite.
Third, the length of extension branches and short joints of main branches at all levels should be basically similar. In order to maintain the subordinate relationship of backbone branches and the balance of backbone branches at all levels, the difference between the extension branches of the middle trunk and the main branch and the main branch and the side branches should not be as big as that of apples, otherwise, the disadvantages of the middle trunk being too strong, the main branch being too weak or too strong, and the side branches being too weak will easily occur. The difference of the length of the main branch extension branch should not exceed 10%. If the extension branch of the main branch is cut off by 50 cm, the length of the side branch should not be shorter than 45 cm.
(3) Pay attention to the opening angle of the main branch.
Pear trees are generally dry and erect with small branch angles. If it is not controlled, it will inevitably lead to small crown, strong growth potential and delayed fruiting. Therefore, the opening angle of main branches, especially the angle of lower branches, is the key to pruning young trees. Opening angle is the key to high yield or not. As soon as the angle is opened, other problems will be solved. There are several ways to open the angle: first, in the growing season, branches are opened by methods such as pulling, taking, dropping and branching, so that the angle of new shoots reaches 60 ~ 70; In February and May, the angle of the main branch should be opened by using the W-type angle opener by pulling branches, supporting branches, taking branches and opening angles. Generally, the main branch angle of 2-3-year-old varieties should reach 60-70, and the branches of 3-4-year-old varieties have grown thick and hardened. In order to prevent splitting, we can use the method of three saws behind the base of the big branch, and then open it with a wooden stick to reach a predetermined angle. Thirdly, pruning the extended branches of the main branches by pushing out the inner buds and opening the main branch angles.
(4) The extension branches of the backbone branches at all levels should be appropriately shortened.
The reason for cutting off the main branches is the same as that of apples (good buds are preferred, sharpness is increased, etc.). ), and promote the branches to prevent baldness, cut off the flower buds at the top of the branches (pear extended branches are easy to form flower buds), and hinder the expansion of the crown.