(1) shortcut
Cut off the annual branches of some fruit trees.
① The degree and type of short cutting can be divided into light, medium, heavy and extremely heavy according to the cutting degree of branches.
Light and short pruning refers to cutting only the top part of branches or cutting 1/3 ~ 1/4 at the blind joint at the junction of spring and autumn shoots. Generally, weak buds or sub-full buds are selected at the cut. After pruning, 1 ~ 2 medium and long branches will be sent out at the cut. The growth potential of branches is weaker or similar to that of the original branches, which can promote the germination rate and form more short and medium branches and foliage branches. In order to alleviate the tree vigor, the auxiliary branches are often cut light and short.
Short-medium cutting refers to cutting 1/2 ~ 1/3 when the annual branches are full of buds in spring or autumn. Intermediate cutting can improve germination rate and branching ability, and promote growth potential. Usually, short and medium cuttings are often used to extend the main branches of young trees and cultivate large and medium-sized fruiting branches.
A heavy and short incision is made at the lower part of the branch or the sub-full bud at the base. Usually, in order to make use of this branch, but control its growth position, the heavy and short parts are used. After severe cutting, 1 ~ 2 vigorous branches and some weak branches often germinate under cuttings.
The extremely heavy stump was cut at the wheel mark at the base of the branch. Weak cutting buds or slightly inclined incision promote the germination of basal cryptobuds. Extremely heavy cutting is often used to weaken the growth potential of branches, because if some branches are thinned, there will be too much space and detention, so extremely heavy cutting should be adopted.
(2) The concrete application of short cutting in plastic trimming. Short cutting is one of the most widely used trimming methods. In order to achieve the following purposes, shortcut method is often used.
When shaping young trees, we should cultivate the backbone branches directionally, increase the number of branches, increase the sharpness, build a solid skeleton and use the middle section.
Promote the rapid growth of young trees, multi-branch, increase the number of branches, expand the crown, and combine medium cutting with light cutting.
Improve branching ability and strengthen tree potential, and use middle cutting.
Use auxiliary branches to cultivate medium and large branches, increase the density of branches and leaves, make full use of space, and adopt middle cutting and light cutting.
By cutting buds, the branching angle is changed and the branching direction is extended, and the middle cutting is adopted.
To rejuvenate the weak branches of weak trees and promote the formation of flower buds, middle cutting is adopted.
Make the auxiliary branch close to the main branch, and adopt the method of combining heavy cutting with light cutting.
Balance the tree potential, weaken the growth potential of local branches, and use light cutting to promote the growth potential of local branches.
Wang Shu promoted the formation of flower buds, using light cutting or delayed middle cutting.
(2) refinement
Cutting off all branches from the base is called thinning.
① Thinning reduces the overall growth. For growth, thinning can adjust the density of branches, improve the light transmission conditions in the crown and adjust the growth potential of local branches; As far as the results are concerned, thinning has played a role in regulating the composition of branches and the proportion of fruit branches. Thin cutting is an obstacle to the material exchange between the upper and lower parts, so it has the dual functions of weakening and promoting the upper and lower branches. The larger the incision, the more obvious this effect is.
(2) The application scope of thinning is mainly thinning the over-dense branches that affect the light; Diseases and insect pests, dead branches and useless branches; Overdense cross branches and overlapping branches; There are too many branches around the flourishing tree, which affects the light and has strong competitiveness; Weak trees have weak branches and too many weak fruit branches.
③ The specific application of thinning promotes local growth. In order to promote the growth of main branches, the upper redundant large auxiliary branches or large branches are drained. First, the wound is large, which hinders the upward transportation of nutrients; Secondly, the illumination conditions of the lower branches were improved, which was beneficial to promote the growth potential of the lower branches of cuttings.
In order not to weaken and inhibit the growth potential of the upper and peripheral branches of the crown, the dense branches in the lower part should be thinned and the injured surface should be increased, which can weaken the growth of the upper branches.
Sparse and redundant, too dense, no reserved branches and branches damaged by pests and diseases.
After thinning the young trees, lightly prune and tightly keep the branches, the peripheral branches are crowded, the branches grow vigorously, the internal branches grow weakly, the light is poor, the flower buds are not easy to form or the fruit setting rate is low, some auxiliary branches and peripheral branches are thinned, the spacing between layers is clear, and the light is seen in the inner room, which promotes flower formation and improves the fruit setting rate.
Promote the flowering of weak branches, just like the dense branches of a tree, which can be thinned and retained. If the trees are leafy and cannot grow into flowers, the leafy branches and upright branches in the upper part should be thinned to weaken the growth potential and promote the formation of flower buds in the middle and weak branches.
Thinning, especially thinning too many big branches, will weaken the growth potential of the whole tree or the thinned branches. When thinning large branches of adult trees, we should pay special attention to the protection of wounds, minimize the big wounds caused by main branches, and leave branches under the incision, which is conducive to wound healing. Avoid continuous "mouth scar" and "mouth scar". Continuous wounds on branches often cause lobular disease. The pruning wound should be flattened and coated with protective agent to protect the wound.
(3) Shrinkage shear (retraction)
Refers to pruning of perennial branches or branches. On young trees, pruning is often used to control auxiliary branches, limit the growth space, weaken the branch potential and turn it into fruit branches. In the full fruit stage, in order to cultivate the middle branch group, we should remove the strong and leave the weak, improve the illumination in the inner room, and shrink the upper and lower branches on the back. Too long drooping branches raise branches, and the main branches of densely planted orchards cross branches or grow continuously for several years, which leads to the outward movement of parts, which is the retraction and rejuvenation of regenerated branches. The trunk branches of aging trees droop, retract and renew, and the dorsal branches or oblique branches on the back are often used to replace the extension heads of the main branches. The application of shrinkage shears should be appropriate. Branches with small number of young branches, strong growth potential or small angle are easy to cause flourishing branches if they retract too much and too fast. Therefore, young trees should not be eager to retract; Trees in full fruit or senescence stage have older branches and their growth potential has softened or weakened. Retraction tends to weaken the branch potential. When cutting, the first branch should be left to maintain its growth potential. Especially when cutting large branches in the inner cavity and middle and lower part of the crown, the baldness at the back is heavier and the first branch at the cutting mouth is weaker. Excessive cutting will seriously weaken the growth potential and often lead to dry rot of cutting branches. Shrinking old trees can stimulate the germination of local latent buds, sprout new branches, renew the crown and prolong the fruiting life.
(4) slow release
It is relative to shortcuts, and if it is not a shortcut, it is called slow release. Slow release is beneficial to the relaxation of branch vitality, the accumulation of nutrition, the formation of flower buds and early fruiting. There are many lateral buds retained in slow release, and many branches in the future; But most of them are medium and short branches, and the strong branches are few. When using slow-release technology, we should pay attention to the following aspects: first, when the main branch is weak and the auxiliary branch is relatively strong, it is not suitable to slow-release the auxiliary branch; Second, in the process of shaping young trees, don't delay competing branches, long branches and flourishing branches on your back or back; Third, the sustained release should be mainly moderate branches. When the number of long branches is too large and the amount of one-time pruning is too large, a small amount can be released slowly, but the branch potential must be controlled by combining measures such as softening, flattening, ring engraving and peeling.