Pruning techniques of Walnut trees

  Walnut branches are mostly terminal bud fruit, in addition to promoting its branches, walnut branches generally can not be truncated, otherwise it will affect the results. For over-dense branches, thousands of dead branches can be thinned, for over-weak branches and sparse parts of the branches can be cut short or contracted, to promote their branches, to achieve the effect of three-dimensional fruit. Adult trees, especially old walnut trees, should strengthen the thinning and shrinking of foreign over-dense branches. With the increase of branch grade, the growth potential of walnut branches becomes weak, and the fruiting ability decreases, and the drying rate increases obviously. The branch grade should be reduced as much as possible by pruning year by year, so that the branches of the tree body should be kept within the range of 3~4 grades, and it is appropriate not to exceed 5 grades.

  Short pruning method is used more often in improved walnut varieties, which is also the main aspect different from the pruning method of seed walnut. Female flower buds of seed walnut are mostly 1~2 buds at the top of fruiting mother branch, so pruning methods are mostly used to thinning branches and putting long, but short cutting method is rarely used; while more than 85% of lateral buds of 1-year-old strong branches of fine walnut can form female flower buds and blossom and bear fruit, short cutting can prevent the fruit part from moving outward, enrich the base, and can play the role of thinning flowers and improving fruit setting rate. The pruning responses varied greatly with the degree of truncation.

  Heavy short cut: for 1 year strong branches, cut off about 2/3 of the branch length, generally cut off 1~2 strong branches, the lower part of the bud is not too full germination or germination into medium and short branches, some of which die after germination, especially excessive long branches, this reaction is more obvious.

  Light short cut: cut off about 1 ~ 3 of the branch length, cut 1~3 strong branches growing vigorously under the mouth, under which many medium and short branches grow. If the branches are strong, nutritious, strong and fruiting, they can bear good fruit. If cut stay too long, leave bud much, hair branch much, the result also is much, but dispersive growth potential, easy to make branch turn weak, and base branchlet dies, very fast bare, cause the result place to move outward.

  Medium and short pruning: about 1/2 of the branches are cut, the response is between heavy and light truncation, 2~3 strong branches can be produced under the cutting mouth, strong growth, low fruit setting rate, 3~4 moderate branches can be extracted under it, good results, high fruit setting rate, full fruit kernels, young trees are shaped, branches at all levels are trimmed, medium and short pruning can be used, which is conducive to expanding the crown and cultivating the fruiting branch group.