1. Head trimming
The trunk of the plant is erect, with a height of 0.6~ 1.2m, with fruiting branches and fruiting mother branches at the top. Because the branches are concentrated and head-shaped, it is called head pruning. This tree can be pruned with short or long tips.
(1) Short tip pruning
It is a tree form formed by the combination of column frame, head pruning and short tip pruning. Because the basal axis of the branch group is branched and extended year by year, it will eventually become a compact small cup.
The advantages of head pruning and short tip pruning are as follows: the tree structure is the simplest, and the plastic pruning technology is easy; After the upright trunk is coarsened and hardened, it can be cultivated without frame; The new shoots droop around and are not tied, which saves labor in management; Farming can be carried out between rows to facilitate weed control; The volume and load of the workshop are small, and the requirements for soil, fertilizer and water conditions are not strict. Most brewing varieties can adapt to this tree shape. Its disadvantages are: large amount of pruning, great inhibitory effect on plants; It is not easy to make full use of space, and the output per unit area is low; At the early stage of growth, the fruit-bearing parts are too concentrated, and the ventilation and light transmission are poor, which has different degrees of influence on fruit quality; The trunk is upright and not suitable for use in cold-proof areas; Results Varieties with low eye knot strength at the base of mother branches were not suitable for introduction.
(2) Long tip pruning
There are 1~4 long branch groups (usually 2) at the head of the plant trunk. If two branches are planted, their new buds naturally droop and are not tied, and a barbed wire frame can be used. The distance between the iron wire and the ground is 1.5~ 1.8m, and two long pointed fruiting branches are tied to the iron wire on both sides (as shown in figure 1). When the new tip has to be tied vertically upwards due to wind disaster or other reasons, it can be used to pull two iron wires. As a result, the mother branch is tied to the first iron wire, and the new tip is tied to the second iron wire vertically upward. If there are four long branches at the head of the trunk, you can use a wide-topped single fence frame, and the four long branches can be tied to two iron wires on the beams on both sides respectively. In order to make the load-bearing branch more firmly fixed on the wire, the long tip can be wound in the direction of wire traction, and then the tip can be tied tightly.
Figure 1 long tip trimming head trimming
Long-shoot pruning has the following advantages: after long-shoot pruning, the yield and panicle quality of varieties with low fruiting intensity at the base of mother branches (such as seedless white) or varieties with too small fruiting branches (such as Cabernet Sauvignon, Pinot Noir and most American varieties) will be significantly improved; Long-tip pruning can make the fruit ears more neatly and evenly distributed on the frame surface, which is beneficial to mechanized harvesting; Pruning of long branches has great flexibility in keeping buds and branches, which can be increased or decreased according to the tree potential and the thickness of mother branches. Its disadvantages are: it is difficult to master the pruning technology, and improper selection of mother branches means that the plant will lose 1/2~ 1/4 yield; It is easy to cause too many results, and the results are easy to move out.
The pruning process of head pruning is as follows: in the first year, if the seedlings form strong new shoots that year, when cutting in winter, leave 4~5 more buds above the specified dry height for short cutting. In the second year, 5~8 new shoots at the top of the trunk were kept, and the rest sprouted. When pruning in winter, the two most robust new shoots are selected as spare branches, and according to the strength of the tree, 1~2 new shoots are selected as fruiting mother branches at the top, with 8~ 12 buds per bud. In the third year, two robust new branches were formed on the lower two preparatory branches, which were pruned in winter according to the long branch group. The upper new branch was used as the long branch to bear fruit, and 2~3 buds were still left in the lower part as the preparatory branches. After two fixed branches are formed, the tree is completed. The mother branch with fruit on the upper part can be cut off from the upper part of the neat branch group.
This kind of tree has small plant load, which is not conducive to making full use of space achievements and low yield per unit area.
2. Fan-shaped pruning
There are many kinds of fan-shaped pruning. Generally, plants have long main vines, bearing branches and bearing mother branches. Large fan-shaped main vines can also be divided into side vines. The number of main vines is generally 3~6 or more, which are distributed in a fan shape on the frame surface, so it is called fan pruning. Plants with or without trunk are called dry fan pruning, and the main vines are cultivated directly from the ground, mainly for the convenience of getting off the shelf for cold protection.
Fan-shaped pruning can be used for both hedge frames and shed frames. At present, natural fan-shaped non-drying multi-main vines are widely used on hedge frames, and as a result, the mother branches are pruned to long, medium and short shoots.
It is easy to shape a natural fan with multiple main vines. If the main vines and branches are reasonably arranged on the shelf surface, the fruit-bearing potential of the plant can be fully exerted and high yield and high quality can be obtained. However, this kind of tree is prone to the following shortcomings: ① Because the flexibility of the tree is too great, the branches and vines on the surface of the tree are messy. Without pruning experience, it is difficult to keep the bud quantity, the density of branches, the arrangement of branches and the degree of pruning appropriate. (2) Because of the long soil and vertical binding, it is easy to appear the phenomenon that the upper part is strong and the lower part is weak. It causes the lower part to move up quickly, making the lower part weak or bare, making it difficult to maintain a stable tree shape.
Therefore, when using fan-shaped pruning with multiple main vines, a clear tree shape (including the number of main vines, the spacing between main vines, the number of branches and the length of bearing mother branches) must be specified according to the plant row spacing and the height of the frame, so it is called regular fan-shaped pruning with multiple main vines. For example, the plant spacing is 2m, the frame height is 1.8m, and four lines are drawn. It is best to adopt a regular fan-shaped structure with multiple main vines. This plant has four main vines with an average vine spacing of about 50 cm. Leave 3-4 branches for each main vine, with the middle tip mainly trimmed, and the height of the main vine is strictly controlled below the third iron wire. When pruning in winter every year, the above shortcomings can be alleviated if pruning can be carried out according to the specified tree shape and the balance of the main vines can be maintained (Figure 2).
Fig. 2 Ordinary fan without trunk and multiple main vines
The pruning process of fan-shaped multi-main vines without trunk is roughly as follows: in the first year, it is best to cultivate 3~4 new shoots from the ground as main vines in the first year of planting. After defoliation in autumn, the stout new shoots of 1~2 can be cut off by 50~80cm, and the thin new shoots of 1~2 can be cut off by 2~3 buds. In the second year, I planted 1~2 main vines last year, and I was able to pull out several new buds that year. In autumn, the stout top is selected as the main vine, and the rest is cut short with 2~3 buds to cultivate branches. Last year, the short-lived main vine could produce 1~2 new shoots that year. In autumn, 1 thick main vine was selected and pruned to different degrees according to the thickness. In the third year, continue to cultivate the main vines and branches according to the above principles. When the height of the main vine reaches the third iron wire and there are 3~4 branches, the tree shape is basically completed.
3. Trunk pruning
There are generally three common types. The first one is called "Dulong Trunk Pruning". The factory has only one one-stop trunk with a length of 3~5m. Most of them are pruned with very short tips and separate sheds, which are often cultivated in dry land in Hebei and Shanxi. The second is to trim two dragons on a large or small scaffolding. Plants grow two main vines (long stems) from the ground or trunk, and short branches are planted on the main vines. The length of main vine is 5~ 15m, which is widely used in northern China. The third type is the single-arm horizontal pruning (as shown in Figure 3) and the double-arm horizontal pruning (as shown in Figure 4) used on the hedge frame, and there can be tall and straight trunks in the cold-proof area.
When dry pruning is combined with short-tip pruning, a branch group (commonly known as dragon claw) is planted on the trunk every 20~25cm. It is best to have 1~2 short branches for each branch group (some places are used to leaving more branches). Long stem pruning is combined with middle tip pruning, but double branch regeneration method must be adopted, and the branch spacing can be increased to 30~40cm.
The following points must be paid attention to when using dragon trunk pruning in cold-proof areas: ① The base of the trunk must have a certain inclination, especially in the section about 30cm near the ground, which is conducive to lying down and preventing cold. When pruning the trunk of the trellis, the main vines should be inclined to the same side, so that the main vines can be inclined forward and sideways, which is not only convenient for going up and down the trellis and burying soil, but also can play a role in slowing down the growth of new buds at the root of the trellis. (2) The number of trunks must adapt to the tree potential.
(1) Hedgehog Long Stem Pruning
In the cold-proof area, horizontal pruning with inclined stem and single arm can be used (as shown in Figure 3). The long trunk is tied to the first iron wire about 0.5m above the ground, and the new tip is tied to the second to third iron wires. If a double-walled fence is used, another main vine can be planted near the ground, and the two arms (that is, the main vine) extend in the same direction. In cold-proof areas, horizontal pruning with both arms and T-frame pruning can be adopted. The plant has a vertically growing trunk with a height of 1~ 1.2m, and its arms extend to the left and right respectively (as shown in Figure 4). The new shoots first grow upward, cross the two iron wires on the upper beam, and then let them droop naturally. After the new shoots spread to both sides and drooped, the ventilation and light transmission conditions of the crown were greatly improved, which was not only conducive to the formation of flower buds at the base of the new shoots, but also to the improvement of berry quality.
The advantages of short branch pruning in the form of dragon stems are: the dragon stems are evenly distributed on the frame surface, and short branch pruning can make the fruiting part compact and easy to maintain a stable tree shape; Strictly control the load of plant buds, and the tree potential, yield and berry quality are easy to remain stable; There is no interference between the new shoots and the ear, so the ear size, color and maturity are the same. The disadvantages of pruning long stems and short branches are: the tree shape is fixed, the elasticity of branches and buds is small, and there is little room for manoeuvre after the main vine or branch group is damaged. Unlike pruning long branches, branches can be pulled from other parts to make up for the vacancy on the shelf surface; Before the new shoots are lignified, they are easily blown away by the strong wind.
(2) There is no pruning process of two dragons in the shed.
In the first year, two new shoots were selected from the place near the ground as the main vines, and brackets were set up to guide them. After defoliation in autumn, mature new shoots over 0.8cm should be cut short by about1m. If the growth of new shoots is weak or the maturity is poor in that year, stubble can also be leveled, that is, 2~3 sections can be cut short from the ground, which can promote the emergence of more robust new shoots in the next year and is more conducive to cultivating the main vines with uniform growth. In the second year, select new branches from the tip of each main vine to continue to extend. After defoliation in autumn, the main branches can generally be cut at 1~2m. The cutting length of extended branches can be expanded and contracted according to the vitality of the tree and its robustness and fullness. The trees with strong potential and strong new shoots can stay long appropriately, and vice versa. It is not advisable to cut it too long to avoid blindness and premature baldness of the main vine. At the same time, we should pay attention not to leave too many fruits in the second year, so as not to delay the completion of the tree. 2~3 buds can be left in the new shoots except the extended branches, which can be chopped and cultured into a branch group. Generally, a permanent branch group is left on the main vine every 20~25cm. In the third year, we will continue to cultivate according to the above principles. Generally, the plastic surgery process can be completed within 3 to 5 years after planting (as shown in Figure 5).
Fig. 3 Single-arm horizontal pruning and short-tip pruning, single-wall hedge frame
Fig. 4 Two-arm horizontal pruning and short-tip pruning, T-frame
Fig. 5 Pruning process of two stemless dragons in the shed.