The pruning principle of young trees in the plastic period and the first fruit period is: plastic mainly, giving consideration to the results. The combination of winter pruning and summer pruning can form more branches and leaves, promote crown expansion, and form and bear fruit early. In addition to the extension branches of backbone branches and the leading branches of big branches, more branches should be left in the crown, so that the remaining branches can be transformed into results as soon as possible. When the branches in the crown become dense and disorderly, according to the arrangement of the main branches, the large and middle branches are gradually selected to be retained, and the small branch group is retained in the configuration of large and middle branches, and unnecessary branches are gradually deleted. The remaining branches can be treated differently in four categories: the first category of branches has an influence on the growth of the extended branches of the main branches, and needs to be re-cut, and then cut after cutting, and cannot be directly cut near the main branches. The secondary branch is located on one side of the main branch, which is inclined and has a large development space. It can be cut from medium to light, promote branching and cultivate into large or medium-sized branching groups. The third branch is located in the dominant position on the back of the main branch, upright and strong, and will be crushed and flattened for a long time when there is space. After the results come out, they will be transformed according to the situation and the long branches will be thinned out. The fourth kind of branches are moderate branches and weak branches, which generally grow long, promote flowering and early fruiting, and are located in a large space. When the space needs to be filled, the upper part of the branch can be deeply cut to promote the transformation to long branches.

On the back of the main branch, only the twigs are left in the young stage, and the length of the branch axis is controlled below 25 cm. Don't leave large and medium-sized branches. If the power is transferred, the branches on the back will become prosperous. In summer or winter, the strong branches should be cut off in time and the oblique weak branches should be left flat.

Apple and pear trees bloom easily, and they can all bloom after long branches are put out. Therefore, it is necessary to properly control the number of fruits, increase the number of branches and leaves, ensure the expansion of the crown, and form plump branches inside the crown. After inputting the results, the long branches in the crown should be treated differently and divided into long branches and short branches, so that a certain amount of long branches can be formed in the crown every year, and the long branches account for about115 of the total number of branches in the whole tree. If there are few long branches, it means that the pruning amount is light and the number of short nodes needs to be increased; If the amount of long branches is large, it means that the pruning is too heavy, and it is necessary to reduce the short cut and leave more long branches. The purpose is to ensure that the tree is strong and lay a good foundation for high yield in the full fruit period.

The principles of tree pruning in full fruit period are: adjusting tree vigor, maintaining good balance and master-slave relationship, updating branches in time, maintaining appropriate branch quantity and branch-fruit ratio, making the fruiting parts young and strong, improving the lighting conditions in the crown, and ensuring the high quality of pears. Pay attention to the following points when pruning:

(1) Trunk branch pruning.

Maintain the growth direction and growth potential of uniaxial extension of backbone branches, adjust the angle of extension branches, and moderately shorten the extension branches of gradually weakening backbone branches. Alternating control method is used to solve the problem of overlapping branches among plants. (2) Pruning of fruiting branches.

The number of fruiting branches and the amount of fruit hanging in the fruiting branch group should be appropriate, and enough backup branches should be left. Medium and large fruiting branches should be strong, with buds and new branches every year. There should be contraction and release between branches and dispersion. In order to ensure that the inner cavity branch group can get enough light and maintain vigorous growth and fruiting ability, the inner cavity branch group has more branches and fewer branches. The robust new shoots in the hole can be put first and then cut, or cut first and then put, and cultivated into new fruiting branches to replace the old branches. Update the weak branches in time by retraction method. (3) Pruning of short fruit branches.

Varieties with short branches should be carefully pruned during the full fruit period. It is advisable that there are no more than 5 short fruit branches in each short fruit branch group, of which 2 fruits are left and 2 ~ 3 are used as preparatory branches to break the terminal buds. Master pruning methods, such as removing the weak and retaining the strong, removing the flat and retaining the oblique, removing the far and retaining the near, etc. (4) pruning long branches.

The long branches on the back of the main branches are cultivated into branches by pruning in summer or long-term equal pressure when there is space, and thinning is carried out when there is no space.