Pruning of different types of branches of Walnut trees

   1. Pruning the backbone branches retracts the backbone branches in time, and retracts the weak backbone branches to the well-growing lateral branches that grow obliquely, in order to raise and prolong the angle of the branches. The height of the tree reaches 3. 5%. About 5 meters in time.

   2. Culture of fruiting branch group and renewal of walnut fruiting branch group are important measures to increase yield, stabilize tree potential, prolong full fruit life, prevent fruit site from moving out and prevent premature senescence. The methods of culture fruiting branch group include first retraction, first cutting and then releasing, and auxiliary branch transformation.

   (1) first release and then shrink, that is to say, the one-year-old strong branches can grow and pull, generally can draw more than 10 new fruit branches, and then retract in the second year, and culture into fruiting branches group. The distribution of branch groups should be dense and uniform, dense but not crowded, large, medium and small. Generally, in the inner chamber of the main branch, there is a large branch group of about 1 meter, a medium branch group of about 60 centimeters, and a small branch group of about 40 centimeters, which should be combined with release, thinning, cutting and shrinking at the same time, and constantly adjust the size, strength and strength. keep the crown well ventilated and transparent, and the branch group grows healthily and bears more fruit.

   (2) cut at first and then put it in a larger space. When cultivating large fruiting branches, one-year-old strong branches were cut short at first, and 1 or 2 strong branches at the front end were thinned out in the second year, and the other branches were grown into fruiting branches. The coring of new shoots can also be carried out in the first ten days of June to make the branches shrink again when they are cut in winter, and the fruiting branches can be cultivated in one year.

   (3) when the auxiliary branch is finished, it can be cultivated into a large branch group by retraction method, generally using the method of first expanding and then shrinking, and the position of the branch group is better than the anticlinal branch. Only the small branch group is left on the back, not the back branch group. The distance between branches and groups is controlled at about 60-80 cm.

The core of the renewal, rejuvenation and pruning of    fruiting branch group is to adjust the contradiction between vegetative growth and reproductive growth in the branch group, to adjust the ratio of vegetative branch to fruiting branch, and to make branch development, flower bud differentiation, flowering and fruit setting in a dynamic virtuous circle. When pruning, the position of the reserve branch should be considered, the weak branch should retract in time, and the strong branch should be released slowly to maintain the healthy growth of the fruiting branch group.

   3. After the pruning fruiting branch group of the result school group is formed, the medium and long fruiting mother branches should be cut to varying degrees every year, the amount of fruit retained should be controlled, the phenomenon of big and small years should be prevented, and the dense branches, thin and weak branches and some male flower branches should be removed in time. The cutting retention of the erect fruiting branch group should not be too high, the retained branches should be less, and there should be 3 to 5 branches, and it should be controlled within a certain range to prevent excessive expansion from affecting the growth of the main branch and the fruit branch. If the oblique branch group is large, it can leave more branches properly, make full use of the space, adopt the methods of retraction and thinning in time, go down and stay, get weak and stay strong, renew the resulting mother branch, keep it growing and healthy all the time, prevent it from being bald and naked, and the result part moves outward.

   4. After the walnut trees were treated with a large amount of fruit, the growth of the upper dorsal branches became weaker and the dorsal branches became stronger, forming the phenomenon of "inverted pulling" of the main and lateral branches. If the opening angle of the original branch is small, the original head can be cut off and the back branch can be replaced. If the opening angle of the original branch is suitable or larger, the back branch should be retracted or thinned in time.

   5. In order not to disturb the shape of the tree, the overgrown branches are generally not retained at the initial stage of fruiting. In the full fruiting period, appropriate selection and retention should be made when there is a free time, and the branch group should be transformed into a branch group by means of truncation and heart-picking as soon as possible.

   6. Secondary treatment of improved walnut varieties is easy to form secondary branches, because the secondary branches are full, the growth is prosperous, the branches are not full, and the base is very long without buds, so it should be treated in time. When there is space, we should remove the weak and stay strong, and pick out the heart from June to July, control the vigorous growth, promote its formation of fruiting mother branch, and remove it in time when there is no space.