First, the main tree
From the perspective of high-quality production, the sparse tree crowns (trunk-shaped or tree-trunk sparse-layered) in the 1960s and 1970s have some shortcomings, such as high crown, poor lighting and inconvenient operation, and are not suitable for use. The row spacing of pear orchards can be 3 m× 4-5 m, such as sparse layered shape, "3+ 1" tree shape, spindle shape and so on.
1, sparse layer: or "middle crown sparse layer", the trunk height is 60-80 cm and the tree height is about 3 meters. The whole tree is equipped with 5-6 main branches, 3 (or 4) in the lower layer and 2 in the upper layer. The main branch of the first layer is generally equipped with three side branches. The first lateral branch is more than 40 cm away from the trunk, the second lateral branch is 40-50 cm away from the first lateral branch, and the distance between the third lateral branch and the second lateral branch can be increased to more than 60 cm, but the lateral branches should not overlap. The main branch on the second floor is generally equipped with only two side branches, the first side branch is 30-40 cm away from the main branch, and the distance between the second side branch and the first side branch can be appropriately increased. The spacing between the two layers of main branches is 1.2- 1.6m, and the included angle between each main branch and the trunk is 60-70 degrees.
2. "3+1"tree: it is a small crown tree suitable for close planting. The stem height is 60-70 cm, and the central stem is obvious. Within the range of 60- 120 cm from the ground, there are 3-4 small main branches randomly distributed, and the included angle between each small main branch and the central trunk is 70-80 degrees, and two large branches (the rest are middle branches) are planted on it. The main branches are no longer cultivated in the upper part of the central trunk, but a large fruiting branch group is arranged every 20-30 cm, generally 6-7. I feel happy after the situation of a lot of fruits and trees has eased. The tree has the characteristics of easy shaping and management. After shaping, the crown has sufficient light, which is beneficial to the improvement of fruit quality.
3. Spindle shape: the height of trunk is 50-70cm, and the height of tree is about 3m. The central trunk is not equipped with main branches, but directly cultivated 10- 14 "small main branches" (or "fruiting branches") without stratification. The axial spacing of each fruiting branch is 20-30cm (the spacing of the same lateral branches is 60cm), and the planting angle with the central trunk is 70-80 degrees. No lateral branches are arranged on it, but the fruiting branches are directly cultivated, and a large number of fruiting trees turn around after the trend relaxes. The difference between tree shape and evacuation layered shape is that there are many main branches or fruiting branches, no stratification and no side branches, and it has the characteristics of easy operation, quick forming, early fruiting and high yield. Moreover, because there are no lateral branches on the axis of fruit branches, the trees are transparent and the indoor illumination is good, which is beneficial to improve the quality of fruits and has positive significance for prolonging the life of fruit branches. However, for varieties with weak branches, it is necessary to do a good job of "eye injury" to promote branches, otherwise it is easy to have problems such as "partial crown" caused by insufficient branches. At the same time, for varieties with vigorous vertical growth of branches, it is necessary to do a good job of "pruning and shaping"
Second, plastic surgery technology
The main task of the plastic stage is to select the ideal tree with reasonable planting layout, suitable angle and balanced growth, make full use of auxiliary branches to make it bear fruit, increase early yield, and at the same time assist the growth of trees and promote crown expansion. Attention should be paid to the cultivation of fruit branches of each main branch (or fruit branch axis): avoid copying mechanically, not following the book and deliberately pursuing "shape"; It should be used flexibly according to the growth potential, angle and fullness of buds, so as to achieve "pruning with trees and shaping with branches"; Long-term planning should be made, and the yield should not be affected by seeking "shape", nor should the early yield be pursued unilaterally, which will affect the development of trees and delay the formation of crown.
1, evacuation layered shape
Year of planting: the fixed stem height is generally 80- 100 cm, which can be reduced to 60-80 cm in windy areas. If it is planted in spring, it needs to be fixed immediately after survival; If it is planted in autumn, it needs to be dried, but the interception height can be slightly higher to avoid the upper buds from drying and bolting; It will be shortened to a predetermined height before germination in spring. 8- 10 full buds are required in the plastic belt to ensure that a sufficient number of new shoots are issued for the main branches to choose from; Varieties with weak branching ability, especially Japanese and Korean varieties, need to accelerate germination and promote their germination; For varieties growing vertically, after the new shoots stop growing, the branches should be pulled and fixed to make them form an angle of 60-70 degrees with the central stem.
Pruning in the winter of the following year: 5-6 strong branches can grow after the general strong seedlings are fixed, and the top strong branches are cut off by 70-80 cm to cultivate the central leadership trunk; For the lower branches, choose 3 ~ 4 branches with good growth position and rotation as the main branches, and cut them short by about 50 cm to promote the development of side branches. It is required to take strong seedlings as the leading factor to facilitate the formation as soon as possible. If the base angle of the main branch does not reach 60-70 degrees, it is necessary to "support" or pull the branch; The remaining branches should not be sparse as far as possible, and they should be leveled (at an angle of 80 degrees) as auxiliary branches, and flowers should be put out to promote flowers and increase early yield. In practice, the short section length of each main branch can be flexibly grasped according to the growth potential and planting density of the branch, but it is generally not less than 40 cm.
Winter cutting in the third year: continue to cut the central trunk, with a length of 70 cm. The short length of the extension head of the first layer of main branches should be 40-50 cm, with strong seedlings as the head. Its function is to promote branching, cultivate two branches, increase the growth of branches and leaves, which is beneficial to the early formation of crown. In principle, the annual branches on the central trunk are no longer cut short, and the growth potential can be delayed by pulling branches to promote the formation of flower buds, but the new buds sprouting on the back of branches should be wiped or cored in time.
Winter cutting in the fourth year: in principle, long release is the main method. For the upper buds, the two branches extending from one row to the other were cut short by about 40 cm to cultivate the second layer of main branches. For the extension of the first layer of main branches, the weak ones can be moderately short and the strong ones should be long. For the branches between the main branches on the first and second floors, those with more flowers can be "cut" off, and those with fewer flower buds can continue to grow, which will make the branches shorter and form flower buds.
2. "3+1"tree
Planting year: classified management according to evacuation.
The second year: cut the central stem at about 80 cm and selectively carve buds (the spacing is 20 cm and the planting direction is staggered). In principle, the sprouting branches at the base should not be cut short, but they should be pulled to 70-80 degrees after sprouting. However, for those with weak growth potential and less than 60 cm in length, it is necessary to cut them properly to enhance the growth potential and shape them as soon as possible.
The third year: the extension branch of the central trunk no longer takes shortcuts. On the central trunk of the second year, the branches drawn after short cutting can be lengthened to promote flowering, but for those with vigorous growth and upright angle, the branches need to be pulled to 70-80 degrees.
Because of the large angle of the above-mentioned plastic square root branches, it is easy to sprout long branches on the back, so it is necessary to strengthen the pruning work such as bud wiping, coring and tip twisting in summer.
3. The method of spindle-shaped stem height and cutting off the central stem is basically the same as that of thinning and layering, except that the main branches at all levels do not cut short and cultivate the side branches, but directly cultivate the fruiting branches by pulling branches and putting them long. In the second year, the central trunk will be shortened by 70-80 cm, and the lower branches will be drawn at 70-80 degrees (the weak ones can be moderately "headed"). In the third year, the central trunk should be shortened to about 80 cm in length and new branches should be pulled out. In the fourth year, the treatment of the central trunk depends on the planting density and the number of cultivated fruiting branches. If the density is low and the number of fruiting branches does not meet the requirements, it is necessary to continue to "head", otherwise it will be long-planted, and the new shoots extracted after cutting the central trunk in the third year will still be pulled out to cultivate fruiting branches.
In addition, the shaping method of apple spindle with good fertilizer and water conditions can also be referenced: the stem height is about 100 cm, and the middle stem is not cut short in the second year (the branches with weak growth potential can be lightly cut), and all the branches sprouted at the base are cut short with extremely heavy weight, only 2-3 weak buds are reserved, and the outer buds are first, so that the germination and growth of each fruiting branch shaft are basically on the same basis. When the spring shoots stop growing, they are pulled to 80-90 degrees, which promotes the germination of short branches and the formation of flower buds while cultivating the tree shape, so as to achieve the goal of "planting trees one year, putting out branches in two years and seeing production in three years". However, due to the strong polarity of pears, most varieties have weak ability to form branches, so it is necessary to do a good job of bud carving and pay attention to controlling the strong branches in the upper part of the crown to avoid the influence of "strong on the upper part and weak on the lower part" on the crown formation.