Winter pruning techniques of grape in northern China

Winter pruning techniques of grapes in North China

In the cold-proof areas, winter pruning of grapes is carried out before the grapes are removed from the shelves. According to the growth strength of the branches, the degree of pruning is also different. In terms of the length of cutting, there are many methods, such as extremely long shoot pruning, long shoot pruning, middle shoot pruning, short shoot pruning, very short shoot pruning and comprehensive pruning of long, medium and short shoots. Very long shoot pruning, generally leaving more than 12 buds per vine; long shoot pruning, 8 ~ 11 buds; middle shoot pruning, 5 ~ 7 buds; short shoot pruning, leaving two or three buds; very short shoots pruning, leaving only basal buds.

The pruning method used in production must adapt to the environmental conditions, frame type, pruning form and the growth potential of the variety. In arid areas, grape plants are generally small, so the planting distance should be properly encrypted and small scaffolding should be used. In the areas where there is plenty of water, grape plants generally grow more prosperous, using "one dragon" pruning, should appropriately increase the row spacing and the use of greenhouse and so on. In order to adapt to the frame type, the corresponding pruning technology must be adopted. It should be pruned mainly by extremely short and short tips; scaffolding and hedge fan shaping, multi-purpose comprehensive pruning of long, medium and short shoots; multi-main vine pruning, mainly long and middle shoots pruning; single-arm and double-arm horizontal pruning, multi-purpose middle tip pruning; hedge four-arm horizontal pruning, then multi-purpose medium and short shoots pruning.

1 long shoot pruning

Long-shoot pruned branches leave more buds, usually 20%-30% more than short-shoot pruning. However, generally long shoot pruning branches have a low sprouting rate, and the number of sprouting accounts for only about 60% of the total number of buds; short shoot pruning branches have a higher sprouting rate, generally 80% ~ 90%. Although the sprouting rate of long shoot pruning was lower than that of short shoot pruning, the actual number of new vines per unit shelf was more. Therefore, as long as it is adapted to local conditions, used properly and adapted to the frame type, high and stable yield can be obtained no matter using long shoot pruning or short shoot pruning.

2 short tip pruning

When the grape plants were pruned with short shoots, the result was relatively fixed. There is only one fruiting mother vine in the unit, and there is no reserve branch. After germination, one new shoot is still left as the fruiting mother vine. This pruning every year is also called a regeneration. When the fruiting position rises, the sprouting tiller at the base is selected as the fruiting mother vine to replace the original fruiting mother vine.

3 pruning medium and short shoots

When medium and short shoots are pruned, the fruiting unit can leave no reserve branches, that is, one branch can be renewed, or two branches can be kept for renewal. After sprouting in spring, two new vines were left on one fruiting mother vine. When pruning in winter, the upper one was pruned with the middle shoot, and the lower one was pruned with the short shoot as a preparatory branch. In the following year, two new vines were cultivated on the reserve branches, and the pruning method was the same as that of the previous year, forming a new fruiting unit. Pruning in this way every year, when the fruiting part rises, the branches sprouting from the base are selected to renew [Yoshama Huayao].

4 "one-stop" pruning

When pruning the grapes with "through-train" pruning every year, the branches with 15-20 buds at the top of each main vine are left as elongated vines, and the lateral fruiting mother vines on the main vines are pruned with short shoots every year, leaving only one or two base buds, so that the result part is more fixed. However, a large "pimple"-shaped mother vine group, commonly known as "dragon claw", will be formed after many years.

In the case of better fertilizer and water conditions and strong plant growth, medium and short shoots can also be pruned alternately, usually mainly short shoots, but middle shoots are pruned on some sturdy branches in order to increase the fruit parts on the shelf surface and increase the yield. After the mother vine is pruned in the middle of the row, it will be trimmed with a short shoot after the fruit is trimmed in the second year to prevent the fruit from moving up and keep the tree strong. The plant pruned by this method usually leaves a new vine with strong growth on part of the "dragon claw", pruning the tips in the row and leaving five or six buds to make it fruit. such vines are commonly known as "knot vines". If the growth is weak, the short vine should be pruned very short, leaving one or two basic buds to sprout the vine as the "turning vine" for next year's result. After the result of the "crutch vine" in that year, it was cut off from the base in winter. With this pruning method, the fruiting area can be increased, but the "twisted vine" should not be left too much, otherwise it will affect the normal growth of the new vine on the "dragon claw", the winter bud differentiation is poor, the second year often can not germinate, but will reduce the fruiting site.

5 comprehensive pruning of long, medium and short shoots

Comprehensive pruning of long, medium and short tips, no fixed result part, suitable for scaffolding and hedge. The degree of pruning depends on the growth of the vine. The elongated vine at the top of the main vine and lateral vine generally leaves 15 ~ 20 buds in the scaffolding and 12 ~ 15 buds in the hedge to maintain its growth advantage. The cutting length of the vine depends on the strength of its growth potential and the distance between its position. Strong vines with a thickness of more than 1.0 cm can be pruned with long shoots, leaving no more than 12 buds at most; medium vines with coarseness of 0.7 ~ 1.0 cm should be pruned with middle shoots, leaving eight or nine buds; branches with coarseness above 0.6 cm should be pruned with short shoots, leaving three or four buds; and weak vines with coarseness less than 0.6 cm should be cut off from the base. Each side vine should maintain a certain distance, the size of the spacing is still below the top of the vine does not exceed the base of the front vine as the principle, so that the branches are evenly distributed on the shelf surface. If the branches grow well within the distance, one or two buds can be left short, which can be used as a reserve for renewal. But the reserve vine should not be left too much, so as to avoid overcrowding, affecting ventilation and light transmission, weakening the tree potential, resulting in a reduction in production.

6 extremely long tip pruning

Under the condition of sufficient fertilizer and water, some greenhouse grapes are also pruned with very long tips. Generally, on a certain part of the main vine or lateral vine, one or two strong new vines are selected as the result of the second year, and the new vines have more than 12 buds. Those with weak growth and poor maturity are cut off from the base. Whether it is the main vine or the side vine, we should pay attention to maintain the exuberant growth of the top extension vine, so that its growth potential is stronger than the middle and lower side vine. In general, the top of the lower side vine is best connected with the base of the upper side vine, that is, the upper and lower side vines are separated by more than 12 buds, and the side vines sprouting within their spacing are cut off from the base. This pruning method is suitable for varieties with strong growth potential. At the same time, because the branches and vines are evenly arranged on the shelf surface, it can make full use of the shelf surface and the yield is higher. However, if there is not enough fertilizer and water to maintain a strong tree potential, it will be prone to a large number of "blindness", resulting in a great reduction in position and a decline in yield. Therefore, it is not suitable to use this method under general conditions.