Naturally growing fruit trees have closed crowns, dense branches, overlapping, cavities and weak trees; Poor lighting and ventilation, serious pests and diseases; The yield is not high, it is easy to bear fruit in different years, and the fruit quality is poor; It is not convenient for fruit harvesting, flower thinning and pest control. Through reasonable shaping and pruning, young trees can accelerate the expansion of crown, increase the number of branches, bear fruit in advance and bear fruit early, and cultivate a tree structure with rational use of light energy, high yield and high quality fruit; Pruning in full fruit period can make the tree develop normally, maintain a good tree structure, basically balance the relationship between growth and fruit, achieve high yield year after year, and prolong the life of full fruit period as much as possible; Old trees can be rejuvenated by regeneration and pruning and maintain a certain yield. Through shaping and pruning, the crown with good structure, firm skeleton and neat size can be cultivated, and the requirements of cultivation distance can be met. Reasonable pruning can make the new shoots grow healthily, the vegetative branches and fruiting branches are properly matched, the branches of different types and lengths can maintain a certain proportion, the fruiting branches are distributed reasonably, strong new shoots and enough flower buds are formed year after year, and the yield is high and stable. Reasonable pruning can make fruit trees ventilated and transparent, with good quality, uniform size and bright color. Full-surface pruning is an important measure in fruit tree cultivation technology, but only on the basis of comprehensive management of soil, fertilizer and water can the pruning function be fully exerted. Moreover, it is necessary to flexibly use plastic pruning technology according to tree species, varieties, environmental conditions and cultivation management level in order to play its role.

Plastic pruning can adjust the relationship between fruit trees and the environment; Regulate the quantity and quality of organ formation; Regulating the absorption, transportation and distribution of nutrients; So as to regulate the relationship between fruit tree growth and fruit bearing. Correct pruning can improve the lighting conditions in the tree, increase the area coefficient of young leaves and make mature leaves distribute in layers; Form a good leaf curtain structure and make full use of light energy; It can also adjust the relationship between individual structure and group structure of fruit trees, improve the ventilation and light transmission conditions of orchards, and use space more effectively. Pruning can adjust the balance between various parts and organs of a tree. Because pruning, on the premise of not reducing root system and absorption, reducing branches of crown can promote the growth of remaining branches and improve photosynthetic efficiency. On the other hand, because of pruning, the leaf area is reduced, the total growth is reduced, and the photosynthetic products and nutrients supplied to the root system are also reduced accordingly, which will inhibit the growth of the root system and then affect the growth of the shoot. Therefore, pruning has an inhibitory effect on the whole, and the effect of stimulating growth can only be shown locally, which shows that pruning can adjust the dynamic balance between the aboveground and underground parts of fruit trees. Pruning can be used to adjust the relationship between vegetative growth and reproductive growth, so that the two types of organs can maintain a relative balance, thus achieving the goal of stable and high yield. Reasonable pruning can make a certain growth every year, form enough flower buds and bear a certain number of fruits. When there are few flower buds, the flower buds should be kept as much as possible during pruning to alleviate the vegetative growth potential and promote the transition from vegetative growth to reproductive growth; When there are many flower buds, it is necessary to sparse flowers and fruits, reduce the amount of fruits, shorten the retraction and promote nutritional growth; At the same time, we can make use of the relative independence of various organs and parts of fruit trees to make some branches grow every year and some branches alternately bear fruit and transform each other, so as to achieve a relative balance between vegetative growth and reproductive growth.

Similar organs of fruit trees also have contradictions and compete with each other, which need to be adjusted by pruning. For branches, we should maintain a certain number, while maintaining a certain proportion of long, medium and short branches. When there are too many long branches, the growth period is long and the growth consumes too much nutrients, which affects the growth of short branches and flower bud differentiation. When there are too few long branches, the overall nutritional growth potential becomes weak, which is not conducive to the production and accumulation of nutrients and is not conducive to growth and fruit. For short branches, the number of excellent short branches should be maintained first, and the short branches with poor quality should be thinned, so that the general short branches can be transformed into excellent short branches.

The essence of pruning is to adjust the relationship between fruit trees and the environment, maintain the quantity and quality of organs, and adjust the absorption, manufacture, distribution and utilization of nutrients by fruit trees, so as to solve the contradiction between the growth and fruiting of fruit trees and achieve the goal of high yield year after year. Therefore, pruning must conform to the growth and fruiting habits of fruit trees themselves and be carried out on the basis of good soil, fertilizer and water management.

The basic principles of plastic pruning are: "pruning by trees, shaping by branches", "overall consideration, combination of length and length" and "combination of light and light"

"Pruning according to the tree and shaping according to the branches" means not only having tree-like requirements, but also flexibly grasping according to different conditions of different plants, moving with the branches, guiding the situation and inducing formation; Tangible and immortal, alive and not chaotic. For the requirements of a tree, we should focus on the tree height, crown size, total number of trunk branches, distribution and affiliation, branch ratio and so on. The pruning of different plants does not need to be consistent, so as to avoid rigid copying and mechanical stereotypes. Excessive pruning is bound to inhibit growth and delay fruit.

"Overall consideration, combining long and short" means considering both the results and long-term success. Considering plastic surgery from a long-term perspective requires both long-term plans and short-term arrangements. Young trees should not only have a good shape, but also be conducive to early fruiting, so as to pay equal attention to growth and fruiting. If we only emphasize plastic surgery and ignore early results, it will not be conducive to the improvement of economic benefits and the relaxation of tree growth. If one-sided emphasis is placed on early high yield and many fruits, it will lead to poor tree structure and weak skeleton, which is not conducive to the improvement of future yield. Both growth and fruit should be taken into account in the full fruit period. On the basis of high and stable yield, strengthen vegetative growth, prolong the full fruit period and pay attention to improving fruit quality.

"Give priority to lightness and combine lightness with lightness" means reducing pruning as much as possible and reducing the inhibitory effect of pruning on the whole fruit tree. Young trees, in particular, should be cut lightly and kept more, which is beneficial to the growth of trees, the expansion of crown, the relaxation of tree vigor and the achievement of early fruiting and high yield. Too light pruning will inevitably reduce the number of branches and long branches, which is not conducive to plastic surgery; In order to build the skeleton, it is necessary to prune the backbone branches at all levels to help them grow and control the results. Only in this way can we cultivate a solid skeleton and cultivate various branches. Auxiliary branches should be cut lightly and put long to promote them to form more flower buds and bear fruit early. It should be pointed out that light shearing must be carried out on the basis of certain growth potential. 1-2-year-old young trees can only be lightly cut and slowly released on the premise of promoting them to produce enough strong branches; Only in this way can a large number of branches appear and increase the number of branches. When the tree is too weak and the number of long branches is small, light cutting and slow release will not only affect the cultivation of backbone branches, but also affect the early fruit. Therefore, more than 1-2 years after planting, short cutting promotes long branches, creating conditions for light cutting and slow release, which becomes the key measure for early fruiting.