Now it is winter, and all kinds of deciduous fruit trees in the north have also entered the winter pruning period. People often say that "peach three, apricot four and pear five years" refers to the time when seedlings grow naturally and bear fruit without pruning management. If reasonable shaping and pruning are carried out, the branch angles can be opened, the formation and development of fruiting branches can be promoted, and the metropolis will enter the fruiting period ahead of schedule.

Therefore, pear tree pruning is a unique and important measure in pear tree cultivation management.

First, how to prune pear trees in winter

When pruning any kind of fruit trees in winter, it is mainly to remove pests and diseases, dense branches and concurrent branches, excessive branches, excessive weak flowering branches and other redundant branches, short-cut backbone branches, auxiliary branches and extended branches of fruiting branches.

Or renew the fruit branches and take back the auxiliary branches that are too long and too long, resulting in a branch group.

Or cut off and extend a part of the excessively weak main branch, so that it can be transformed into strong branches and strong buds in the second year; Adjust the angles and growth directions of main branches, auxiliary branches and fruiting branches.

Pruning of fruit trees in winter is generally carried out during the period from defoliation to germination in the second year, that is, dormant period. During dormancy, fruit trees store enough nutrients, and the number of branches and buds decreases after pruning, which is beneficial to the centralized utilization of stored nutrients, and this is the period when new shoots store the least nutrients.

The purpose of pruning pear trees in winter is to strengthen the branching ability, control the position of new branches, build the crown skeleton, cultivate the rejuvenated fruiting branches and coordinate the relationship between fruit and growth.

Pruning pear trees in winter needs three aspects: variety, tree vigor and flower bud. According to the characteristics of cultivated varieties, the strength of growth and the number of flower buds, the pruning methods are determined, that is, four methods: short cutting, retraction, slow release and dewatering.

Second, how to choose four methods

1, shortcut

Short cutting is also called short cutting, that is, cutting off a part of annual branches, which is a technique used for annual branches.

Short cut can be divided into four methods according to the length of cut branches: light, medium, heavy and extremely heavy short cut.

Light and short cutting, that is, cutting a small section at the top of an annual branch, such as cutting only the terminal bud or cutting a small section at the front end.

Light cutting, short cutting, light cutting, more buds left, scattered nutrition, and the cut buds are all half full. Therefore, the growth of branches is not prosperous, and medium and short branches often appear, which can slow down the growth and promote the differentiation of flower buds.

When pruning pear trees, if it is to weaken the advantages at the top of branches, light pruning and short pruning can be adopted.

Medium and short cut, usually cut at the full bud in the middle of the annual branch.

Because there are few buds left, and the nutrition is concentrated, there are full buds cut, and often branches are few and strong, long branches are many, short branches are few, and mother branches grow fast. This kind of short cutting is suitable for strengthening the growth of extension branches of main branches.

In order to promote the branching of pear trees, short and medium cuttings can be used to increase the number of branches.

Heavy and short cutting is a short cutting method of cutting under the full bud of annual branches.

Because there are few buds left, few branches germinate after cutting, and the nutrients are concentrated, and the branches often appear thick and lush. Generally, only 1 ~ 2 vigorous long branches or middle branches are produced under the cutting mouth, with small growth and strong cutting branches. This shortcut is often used to cultivate fruiting branches.

In order to weaken the growth of local branches and promote the growth potential of local branches, pear trees can adopt heavy short cutting or medium short cutting.

Extremely heavy chopping, that is, only 1 ~ 2 chopped buds are left at the base of the branch.

Extremely heavy short cutting is short and has few branches, but because it cuts thin and withered buds, some have strong branches of 1 ~ 2, and some only take out twigs of 1 ~ 2 and remould them.

Pear trees are often used to grow long branches and cut short branches in competitions. When used in middle branches, the effect is good.

The short section of pear trees is not invariable, and sometimes the flowers are too much. In order to reduce the number of flower buds, improve the quality and fruit setting rate of flowers, control the yield and promote the regeneration and rejuvenation of local branches, light and short cutting or medium and short cutting can be used. For another example, in order to change the growth angle and direction of branches, we can also cut off buds moderately, either light or heavy.

Step 2 retract

Retraction, also called shrinkage cutting, refers to cutting off a part of perennial branches.

Branch shrinkage can promote the growth and germination of latent buds, and has a strong weakening effect on mother branches. Pruning reaction is related to retraction degree, branch retention strength and pruning size.

If properly retracted, it can promote the growth of branches and buds behind the incision; Excessive retraction will inhibit growth. Therefore, retraction has dual functions of promoting growth and weakening growth.

The branches of fruit trees retract, which is often used to promote the regeneration and rejuvenation of backbone branches, branches or old trees; Weakening is often used to adjust the growth potential between main branches and control or weaken auxiliary branches.

Pear trees shrink inward, mainly by cutting off perennial branches. After retraction, the total growth of branches decreased, but it promoted the branches near the incision. In order to prevent the growth of the cut branches from being weakened, protective branches should be left when the branches are shrunk.

3, refinement

Thinning is thinning, that is, cutting off too dense branches from the base to improve ventilation and light transmission conditions.

Thinning can reduce the density of branches in the crown, avoid the formation of "trees on trees" by upright branches on the back, improve the ventilation and light transmission conditions in the crown, enhance the photosynthetic capacity of leaves, promote the healthy growth of the rest, and promote flower bud differentiation and fruit development.

For strong backbone branches or branches, thinning strong branches can weaken their growth and balance the tree potential. By thinning out different types of branches, we can also adjust the proportion of leaves and buds and the number of flowers and fruits.

Generally speaking, the cut left on the mother branch after thinning can inhibit the upper part and promote the lower part, that is, the branches above the cut have obvious weakening effect, and the closer to the cut, the greater the weakening effect; However, it can promote the strength of branches below the cut, and the closer to the cut, the greater the promotion. Does this look like a cut or a ring cut?

Therefore, thinning has a good effect on improving light, relaxing tree potential and promoting flower bud formation.

But the degree of thinning depends on the tree, which is more or less sparse.

Like young pear trees, it is important to grow trees so as to increase the amount of branches and leaves, and to sparse branches as little as possible so as to bear fruit early. After entering the fruiting period, on the basis of not affecting the yield, it can be moderately thinned, which can enrich the fruiting branches and stimulate the growth of the branches.

For mature pear trees, because there are too many branches, they can be thinned. Pear trees entering the aging stage have many short branches and weak growth potential. Carefully prune fruit branches to promote growth and restore tree vigor.

Knocking on the blackboard focuses on the fourth technique, that is, playing slowly.

4. Sustained release

Slow release is also called throwing release and long release, that is, no pruning.

Slow-release branches have no cutting and stimulation, but they can slow down the apical dominance, promote the germination of lower buds of branches, increase the germination rate, slow down the growth potential of branches, stop growing early and accumulate more nutrients, which is beneficial to the formation and fruiting of flower buds.

For young pear trees and prosperous trees that should bear fruit but not bear fruit, the slow-release pruning method can promote their early fruit, which is also a common pruning method for these trees and new pear trees.

Slow release can weaken the growth potential, increase the growth, and weaken the branching ability of annual branches, whether they are long branches or middle branches.

Slow release can promote the formation of flower buds and improve the early yield of pear trees. However, if you put the young pear tree slowly for many years without pruning, the final result will be that the branches of the pear tree are chaotic and slender, and some of them will move out seriously.

Therefore, when we slowly prune young pear trees, we must look at the tree situation, that is, young pear trees grow vigorously and flourish. After 1 ~ 2 years of slow pruning, the tree tends to relax or flower buds have formed, so it should be adjusted by cutting or shrinking in time after the results.

For pear trees with weak growth potential, slow-release pruning is generally not used to avoid reducing fruit setting rate and fruit quality.

In addition, medium branches, oblique branches and transverse branches are generally suitable for long placement. On the other hand, the top of the upright branch has strong advantages, and the mother branch thickens quickly, which is easy to form the phenomenon of "tree on the tree". These branches should not be put too long. If it is necessary to extend the length, measures such as bending branches and pruning must be taken to control it in summer.

In a word, pruning pear trees and other fruit trees is an extremely important management measure. When pruning, we must correctly judge the basic situation of the tree and then use what method to prune it. At the same time, it should be noted that winter pruning and growing pruning can not replace each other, but complement each other. The stimulating effect of pruning in winter on local growth can be alleviated by pruning in growing season. For example, after pruning the vigorous branches on the back in winter, we will send out branches here in spring, and even send out strong branches, so that we can wipe the buds in spring.