(1) The planting density of grapes in hedgerow plastic facilities is generally high, and the spacing between plants is 50 ~ 100 cm, so the plastic methods should be different. If the plant spacing is 50 cm, a single main vine can be used for shaping. When pruning in winter, the length of the main vine is 1.5 ~ 1.8 m, and there are no fruiting branches on the main vine, so the main vine is the fruiting mother branch. When the annual planting system is adopted, no spare branches are left on the main vine; In the multi-year planting system, reserve branches can be left at the base of the main vine, and reserve branches do not leave inflorescences. When pruning in the next year, cut it from above the preparatory branch, and the preparatory branch will become the fruiting mother branch of that year (Figure 38).
Fig. 38 Pruning of a single main vine
1. One-year planting system. 2. One-year planting system with branches.
If the plant spacing of 100 cm is adopted, double main vines can be pruned. In the year of planting, each grape chooses two new shoots as the main vines. Plastic surgery, one plant a year can leave no preparatory branches; A multi-year planting system can leave a stout new shoot as a preparatory branch at the base of each main vine, and remove the inflorescence on it. When pruning in the winter of the following year, it is cut from the top of the preparatory branch, and the original fruiting mother branch is replaced by the newly left preparatory branch, and then it is circulated once a year (Figure 39).
Fig. 39 Pruning double main vines
1. One-year planting system. 2. One-year planting system with branches.
(2) Fan pruning with multiple main vines Each grape has multiple main vines, usually 3-6. It is a common pruning method in hedge cultivation, but it is not suitable for high-density cultivation. At present, natural fan-shaped vines with no trunk and many main vines are often used in protected cultivation (Figure 40). The natural fan-shaped pruning of multi-main vines is more flexible and the pruning technology is easier to master; The load of plant bud eye is easy to adjust, which is suitable for varieties with different growth potential. As long as the ventilation and light transmission are paid attention to and the branches are evenly distributed, a higher yield can generally be obtained.
Fig. 40 Natural fan shape of several main vines.
The pruning of natural fan-shaped multi-main vines is to cut off 2 ~ 4 buds in the same year of planting, and 2 ~ 4 new shoots can grow as main vines. If there are not enough main vines in that year, leave annual branches in the second year and cut off 2 ~ 4 buds to form multi-main vines. The next year, the fruiting branches of the main vine were used to bear fruit. When cutting in winter, leave 2 ~ 4 buds for the current branch and 6 ~ 8 buds for the stout branch at the top, so that each vine has 3 ~ 4 branches. However, single-branch regeneration or double-branch regeneration can be implemented, and the method is simple and easy to master.
(3) Trunk pruning is often used in nature reserves when it is cultivated in shed. According to the planting spacing, single-dragon stem pruning and double-dragon stem pruning are adopted (Figure 4 1). When the plant spacing is 50 ~ 60 cm, the stem of Dulong is pruned; When the plant spacing is 1.0 ~ 1.2 m, double-dragon stem pruning is adopted. The pruning method of dried dragon is also relatively simple. Short branches are mainly pruned, and a fruiting branch group is left on the trunk every 20-30 cm. When pruning in the second year, 1-2 fruiting mother branches are left on each fruiting branch group, and 3 buds are cut from the fruiting mother branches, and the previous pruning is repeated every year.
Figure 4 1 Trunk Pruning
1. Dulong dry type 2. Shuanglong dry type
The main point of pruning of Shuanglong trunk is to select two new shoots from the ground in the first year, and the pruning in the future is the same as that of Dulong trunk.