Main pruning methods of walnut fruit trees

   1. Truncation refers to cutting off part of an annual branch. In young walnut trees, the method of developing branches by cutting short is commonly used to increase the number of branches. The truncated object is an exuberant developing branch from the first and second lateral branches, which can promote the growth of new shoots and increase the branches. When the pruning length is 1 / 4 / 1 / 2, about 3 longer branches can be germinated after short cutting. Through truncation, the top advantage of the cutting bud was changed, and the new shoots grew vigorously, which could promote the branching and improve the branching ability. The medium-long branches or weak branches on the walnut tree should not be cut short, otherwise the lower part of the tree should be stimulated to send out thin and short branches, and the tissue will not be investigated, which will easily lead to sunburn and dry up in winter, affecting the tree potential.

   2. Long growth means no pruning of branches, and its function is to ease the growth potential of branches, increase the number of medium and short branches, help to accumulate nutrients, and promote the fruit of young trees. Except that the upright branches on the back should not be released slowly (can be flattened and released slowly), the slow release effect of the other branches is better.

After the long release of   , the drawing branches can produce many and short branches, but only a small number of long branches can be produced on the branches, which is easy to cause the rear light and the result part to move outward.

After long-term release of   , different varieties and different branches had different responses. For the upright varieties and upright branches, only a small number of branches are produced and the growth is exuberant, and there are no branches in the middle and back, which is easy to cause the rear baldness and the fruit part to move outward, while the branches which are more open and open at an angle can sprout a large number of branches, the fruit setting rate is high and the fruit position is compact.

   3. Thinning the branches from the base is called thinning technique. The objects of thinning are generally male flower branches, disease and insect branches, dry and withered branches, useless overgrown branches, overdense crossed branches and overlapping branches and so on. There are too many branches of male flowers, which consumes a lot of nutrients when flowering, which leads to the weakness of the tree, so it should be properly removed during pruning to save nutrition and enhance the tree potential. Dead branches are breeding places for diseases and insect pests, which should be removed in time. When the density of branches inside the crown is too high, in line with the principle of removing the weak and staying strong, the branches that are too dense should be removed at any time to facilitate ventilation and light transmission. When thinning branches, they should be cut off close to the base of the branches, and do not leave piles, so as to facilitate the healing of the cut.

The compound leaves of    walnut tree should be enlarged, and there should not be too many remaining branches. We should timely remove erect strong branches, cross branches, overlapping branches, over-dense branches, thin and weak branches, male flower branches and big branches behind, solve the condition of ventilation and light transmission in the inner chamber, rejuvenate fruit-bearing branches, and improve fruiting ability. The upper part of the upright variety is easy to produce a large number of strong branches, which should be removed in time. Otherwise, it is easy to cause the lower branches to die. As a result, the site moved outward.

   4. Shearing is called retraction or shearing for perennial branch pruning. The effect of retraction varies according to the location of retraction, one is rejuvenation, the other is inhibition. The application of rejuvenation in production has two aspects: one is local rejuvenation, such as retraction and renewal of fruiting branches, perennial lengthy and sagging slow-release branches, etc., and the other is rejuvenation of whole trees, mainly aging trees. Update. The application of inhibition in production mainly controls the strong auxiliary branches and suppresses the strong backbone branches in the imbalance of tree potential. When a large wound is caused by retraction, it can weaken the growth potential of the first branch under the wound, and the overweight retraction of prosperous trees is easy to promote vigorous branches. the location and severity of retraction should be well grasped in production.

   with different degrees of retraction has the effect of rejuvenating the lower part, but the retraction part and the thickness of the branches have different rejuvenation effect. The position of retraction is related to the location and growth strength of the first branch under the shearing mouth. Generally, when the first branch under the cutting mouth grows vigorously and the position is close to the top, the rejuvenation effect is good, otherwise the effect is poor.

   5. Coring and de-sprouting is to remove the top part of the new shoots of the same year, which can promote the occurrence of secondary shoots and increase branches, and the main and lateral branches of young trees can prolong the coring of branches and accelerate the shaping process of branches. The core removal of the erect branch of the inner chamber can promote the life of the oblique branch, ease the growth potential and bear fruit early. Often used for shaping and pruning young trees.

The reaction of    coring and scratching: in the stage of young tree shaping, the apical buds of many walnut shoots were hypertrophy, the dominance was strong, and the sprouting lateral branches and short branches were weak. It can pick the heart when the new shoot is 60-80 cm long in summer and promote 2-3 branches, which can enhance the shaping effect of young trees and take shape earlier. The branches with extended perennial axes, especially the bare-legged branches with a diameter of about 1 cm, can be scratched above the annual wheel marks, reaching to the xylem, which can promote the hidden buds to sprout new branches and promote the fullness of the branches.

After    pruning in winter, especially after thinning big branches, it often stimulates the germination of latent buds under the wound and forms many strong strips, so removing too many sprouts in time in the early growing season is beneficial to tree shaping, saving nutrients and promoting the healthy growth of branches. In the process of shaping young trees, useless branches often germinate, so it is better to wipe them off by hand when they first germinate, so that they are not easy to sprout again. If they grow up, they will sprout again.

From the second year, the young    walnut trees have vigorous shoot growth without coring, and the branch length can reach 1.5 to 2 meters. The coring should be carried out in summer, which can promote branches, increase the number of branches, expand the crown as soon as possible, increase the number of fruiting mother branches, early fruit and high yield. The branches with exuberant growth length of about 60 cm are coring above semi-Lignification.

   6. The opening angle increases the branch angle and relaxes the growth potential by means of bracing, pulling and falling, which is a common method to regulate the growth potential of main branches, improve light conditions and promote flower bud differentiation during young tree shaping.