The pruning period and method of pear trees

The pruning period of pear trees is divided into dormant period pruning and growing season pruning. Pruning methods in different periods have their own emphasis and complement each other. The pruning effect and the reaction of the tree after pruning are also very different, so they cannot replace each other.

1. Dormant period pruning method

Dormant period pruning is also called winter pruning, which refers to pruning from the time the pear trees fall off their leaves in winter to before they sprout in the following spring. It is mainly used for tree shape cultivation, crown expansion, fruiting branch cultivation and auxiliary branch transformation. The main pruning methods include: short cutting, retraction, thinning, slow pruning, etc.

(1) Short pruning

Also called short pruning, it refers to the pruning method of cutting off part of the one-year-old branches and retaining part. According to the degree of branch truncation, it can be divided into the following types, with different functions and purposes.

①Light cutting

Cut off 1/5 to 1/4 of the total length of one-year-old branches. The buds at the cut end are generally weak buds or sub-full buds. After pruning, it can slow down the growth of branches, increase the formation of short and medium branches, and promote the formation of flower buds. After the annual branches of a pear tree are lightly cut, flower buds will generally form in the second year and bear fruit in the third year.

① Middle cut

Cut the upper part of the 1-year-old branch at the fullest bud, and cut off 1/3 to 1/2. Its function is: strong ability to grow long and prosperous branches, few medium and short branches, strong growth potential, which is conducive to the expansion of the crown of long trees. Often used to extend branches from backbone branches.

② Heavy cutting

Cut down the middle and upper half-full buds of the one-year-old branches, and cut off 2/3 to 3/4 of the total length of the branches. After pruning, 1 to 2 vigorous branches and medium-short branches can be produced, which can weaken the tree vigor. Used to cultivate fruiting branch groups and shorten branch rachis.

③ Extremely heavy cutting

At the base of the one-year-old shoot, leave 1 to 3 deflated buds and cut them short, so it is also called "three-bud cutting". Because the cuts leave shriveled buds, new branches will be weak. Used for exchanging large for small, strong for weak and cultivating compact groups of twigs.

After the branch tips are short-cut, the position of the cut buds will be different, and the direction of the new shoots will also be different. When the outer buds are left, the new shoots from the cut buds extend along the direction of the original branches, which is conducive to the opening angle of the main branches. When the buds are left on the back, the angle of the new shoots can be raised, which is conducive to restoring the growth potential. It is used for the renewal of old trees and the rejuvenation of weak branch groups. Leaving side buds can change the horizontal direction of the branches and extend along the direction of the buds.

The distance between the buds at the cutting edge during short pruning is: If you start pruning early in winter, you can leave 1 to 2 centimeters. If you start pruning late and the buds germinate soon after pruning, you can leave about 0.5 centimeters.

(2) Retraction:

Retraction is also called pruning, which is to shorten the perennial branches. After pruning, a large amount of branches are removed to free up more space, which can improve the lighting conditions; at the same time, the stimulation is heavy, which has the effect of renewal and rejuvenation. It is mainly used to control the crown and auxiliary branches, renew and rejuvenate trunk branches or old trees, and improve the ventilation and light transmission of the tree.

Retraction of the drooping branch group

The drooping branches on the branch axis are too long and should be retracted to the middle and rear branches to restore the growth potential of the branch group and form a medium-sized branch group.

Retraction of large perennial branch groups

In order to restore the growth potential of the branch group, the branches can be appropriately retracted.

The angle of opening the backbone branch. When there are two branches with similar growth potential at the tip of the backbone branch, use the back branch as an extension branch and retract the upright branch on the back.

Retraction of the uniaxial fruiting branch axis

The uniaxial fruiting branch group formed by the slow growth of the fruiting branches over the years is too long, affecting the transportation of nutrients, and the quality of the fruit is also affected. If it is poor, it should be retracted where there are branches at appropriate locations.

Renewal of senescent branches

For large trees that have entered the senescence stage, the branches are often bare at the back. When new branches occur, the new shoots must be used to retract and rejuvenate.

Densely growing and retracting branches

During the fruiting period, if the trees are not pruned properly, densely growing and intersecting branches often occur, which affects the ventilation and light transmission in the canopy. , the densely packed branches should be retracted appropriately.

Retraction of auxiliary branches

When auxiliary branches are too large or too long, affecting the growth of the main branches, they should be retracted to make way for the main branches

(3) Thinning: refers to thinning out one-year branches or perennial branches from the base. The main function of thinning is to reduce branches and remove overly dense branches, thin branches, diseased branches, and competing branches, thereby improving the ventilation and light transmission conditions in the canopy, reducing nutrient consumption, restoring tree vigor and maintaining good health. tree shape.

① Clustered branches. The pruning cuts on the backs of large branches are prone to produce many clustered branches. If there is space, 1 to 2 can be left appropriately, and the rest should be thinned out to avoid consuming nutrients.

② Competing branches. In order to enhance the growth potential of the extension heads of the backbone branches, the competing branches should be thinned out.

③ Drooping branches, retrograde branches, and parallel branches are mostly caused by improper pruning in the inner and outer parts. From the aspects of adjusting the tree shape and ventilation and light transmission, it should be appropriately thinned out.

④ Sprouting branches. Sprouting branches breed on the main trunk of the ground. They are useless and consume nutrients and should all be thinned out.

⑤Upright branches on the back. When a branch changes direction and becomes flat, the top advantage is transferred. There are often dense upright branches on the back, and some of them should be thinned out.

⑥ Parallel and crossing branches. For some reason, several large branches grow side by side or cross each other. Weak ones or those with improper status should be removed.

⑦ Leggy branches. The hidden buds of pear trees have a long life. Due to certain stimulation, the hidden buds germinate and form leggy branches. When there is space for the tree, they can be shortened and transformed into fruiting branch groups. When there is no space, they should be shortened. Remove them to avoid consuming nutrients and affecting ventilation and light transmission.

⑧If there are too many main branches, you should choose to keep them in good locations and thin out the rest year by year.

⑨ For short fruiting branches, in order to rejuvenate the growth potential of the short fruiting branches, thin, drooping, upright and overly dense flower buds should be thinned out to maintain the fruiting ability of the short fruiting branches.

(4) Slow release: also called long release or dump release, that is, the one-year-old branches are not cut and allowed to grow naturally. Slow release is beneficial to increasing the growth points of branches and the total growth of the whole tree. After short, medium and long branches are released slowly, they not only have high germination power, but also easily form short flower buds. It is mostly used on saplings and first-fruiting trees.

① The slow release of flat and slanting medium-long branches is conducive to the formation of short branches and stops growth earlier, which can increase the proportion of flowers and the yield of a single plant.

② To slowly release strong upright branches, flatten the branches first and then slowly release them. When slowing down strong and vigorous branches, attention should be paid to the angle and location. Branches parallel to the extended branches of the main branch should increase the angle.

③The uniaxial extension of the fruiting branch group is slow, which is beneficial to slowing down the growth potential, promoting the formation of short branches, and increasing the number of flowers. Slow it down to a certain extent and then retract it.

④ Slowly extending the branches and slowing down the backbone branches at all levels can increase the angle of the backbone branches, increase the proportion of short branches, and ease the growth potential.

2. Growing season pruning

Growing season pruning is also called summer pruning, which refers to pruning during the period from spring budding to autumn leaves falling. During the growing season, pruning is in the period of growth and change of branches. It can adjust and resolve various conflicts in time according to the growth conditions of branches, leaves, and fruits to ensure normal growth results. Therefore, growing season pruning has attracted more and more attention, and exceeds winter pruning in terms of labor and time. During this period, less scissors are used, and the main pruning measures are eye cutting and section carving, bud wiping, topping, branch removal, corner cutting, and circumcision.

(1) Eye injury and segmental carving: refers to using a knife to cross-cut the cortex above or below the buds and branches, making the incision as deep as the xylem. Before germination, injuring the buds with missing branches can promote the germination of new branches; in order to inhibit the growth of certain buds, injure the lower buds. Carving long branches every 10 centimeters can promote the growth of short branches and flower buds.

(2) Wiping buds: When the buds have just sprouted in spring, wipe out the buds that are prone to leggy branches under the saw cuts, on the backs of curved branches, and on the backs of flattened branches. The main purpose of wiping the buds is to save nutrients, improve light, and improve the quality of the remaining branches

(3) Topping: refers to removing the tip of the new shoots with hands or scissors when they grow to an appropriate length. , generally 4 to 8 cm in length, and cut off 1 to 3 leaves under the cut to leave half of the leaves. The time for topping can be determined according to the purpose of topping.

① Promote the development of lateral buds of new shoots. If the new shoots are allowed to grow naturally, nutrients will be concentrated in the top growth point, and the lower lateral buds will often be underdeveloped. After topping, the growth of new shoots is suspended, and nutrients are concentrated in the formed new shoot tissue. The side buds develop fully and abundantly, and more short and medium branches can germinate in the next year.

During the topping period, when the new shoots are 20 to 25 cm long, the first topping is performed. After topping, the secondary shoots are produced. When the secondary shoots are 10 cm long, the second topping is performed.

② Promote the formation of fruiting branch groups. One-year branches sprout multiple new shoots in spring, often forming strong branches in the upper part and weak branches in the lower part. Topping is performed when the new shoots of the upper strong branches are 20 to 25 cm long, which can inhibit the growth of the strong branches, and the weak branches in the lower parts can receive sufficient nutrients, which is conducive to the formation of fruiting branch groups, and these fruiting branch groups are close to the main branches.

③ Regulate the growth of main branches. During the sapling shaping process, topping strong main branches when they reach a certain length can promote the growth of other weaker main branches, thereby balancing the development of each main branch. In addition, topping the slender main branches can make them plump and plump.

④ Promote fruit hypertrophy. After topping the new shoots, more nutrients are concentrated on the fruit and promote fruit development.

(4) Holding branches: When the new shoots have become lignified in July, hold the branches with your hands, bend them from the base, listen for the sound of breaking, but do not break, and then every 5 Centimeters, bend it until it reaches the top of the branch. If the branches are too strong, they can be bent several times continuously, and the branches can be bent into a horizontal or drooping shape. Holding branches can change the posture of the branches, slow down the growth momentum of the branches, and promote the formation of flower buds.

(5) Angle opening and direction change: Pear trees have strong polar growth, and the branches are hard in winter. When the branches become soft from May to June, they can be planted by pulling branches, supporting branches, falling branches, and separating branches. Branches and other methods are used to change the direction and opening angle of the branches in every possible way.

① Use a plastic rope, hemp rope, etc. to tie one end of the branch to a wooden stake and wedge it into the ground. The other end is tied to the appropriate part of the backbone branch. Pull it apart to a certain angle. After a season of growth, it will When the angle is fixed, release the rope.

② Supporting branches The branches of newly planted saplings are easy to stand upright and grow in groups. You can use toothpicks to prop them up at the base of the branches. Or use bamboo to make needles that are as thick as knitting sweaters. They are 7 centimeters long and have extremely pointed ends. They are inserted into the bark of the tree at the base corners of the branches to hold them firmly.

③ Pin the upright branch on the back to other branches to change its direction. Or use No. 8 lead wire, 15 cm long, bent into a "W" shape, and pin it to the base of the new shoot.

④ Falling branches: Use a woven bag or the like to fill an appropriate weight of soil, hang it on an annual branch, and level the branch.

, should be used with caution.