Grape pruning in winter is to cultivate ideal tree shape, adjust the contradiction between growth and fruit, and obtain higher yield. Whether the winter pruning is good or not directly affects the growth and results in the second year or even many years later.
Winter pruning is carried out during the dormant period to bleeding period of deciduous leaves in the second year, generally from 65438+February in winter to 65438+1October in the second year. Pruning too early will stimulate the tree to sprout and branch, and pruning too late will make the tree weak because of bleeding.
When pruning in winter, the pests and diseases, old and weak branches should be cut off first, and then the number of branches and buds left by the bearing mother branches of each plant should be considered. For small trees in plastic surgery, it is necessary to cultivate trees and prune them according to the needs of trees.
First, correctly identify branches.
When pruning in winter, whether the quality of branches can be correctly identified directly affects the quality of pruning. Branches with too long internodes of the same variety belong to long branches, with dark brown and dull skin, and the pith accounts for more than half of the diameter of the whole branch, which is an immature mother branch. This branch is not suitable to be preserved as the fruiting mother branch. Branches and vines are stout, with yellowish brown or reddish brown skin, bright color, short internodes, prominent nodes and thick and full buds. They are excellent mother branches and are easy to bear fruit in the next year, so they should be preserved as much as possible.
Second, the determination of pruning length and bud retention
When pruning, it is customary to call 1-3 buds short branches, 4-7 buds medium branches and 8 buds or more long branches. When pruning young trees, because of their vigorous growth, medium and long branches can be used as the main pruning method to avoid unnecessary new shoot growth in the next year, and at the same time, it is beneficial to expand the crown and form early. For the pruning of old trees, the pruning of medium and short tips is the main way to rejuvenate.
Third, pruning
Grapes are generally pruned by double branch regeneration.
Leave a fixed fruiting branch group on the vine at regular intervals, generally 20-30 cm. When pruning in winter, each bearing branch group leaves two mature branches near the old vine. The upper branches are left long, usually 3-5 buds are used as fruiting mother branches, the lower branches are close to the old vines, and 2-3 buds are cut short as spare branches. When cutting in the winter of the following year, thinning the upper fruiting mother branch, selecting the top 1 year-old mature branch from the lower preparatory branch, cutting off 3-5 branches as fruiting mother branches, and keeping the lower branches close to the old vines as preparatory branches, which is repeated once a year.