01. Biological characteristics of hawthorn trees
Hawthorn has the characteristics of fruiting on strong branches, branches, sunny surfaces, and leaf curtain surfaces, and has strict light requirements. Therefore, the light-receiving parts, the number of fruit branches, and the number of fruits of hawthorn are very significantly higher than the shade parts in the canopy. Experience has pointed out that on sunny days in summer, there must be more than 3h of direct light to ensure normal results; good fruit trees need to have more than 5h of direct light.
The shape of the hawthorn tree should be as small as possible into a tree shape with few main branches, layered and the largest light surface area. In pruning, the quality of the shoots should be improved as much as possible, and the proportion of the first and second types of fruiting mother branches should be increased. In terms of methods, we should use as much as possible to retract, thin branches, and use less short cuts, and at the same time combine the comprehensive use of various techniques such as pulling branches and twisting branches, ring peeling and picking hearts. In terms of time, as far as possible to do a good job in winter pruning, adjust the skeleton and branch structure, and combine the comprehensive application of flowering technology measures in the growing season.
02. Characteristics of plastic pruning in different tree ages
1. Pruning characteristics of young trees and early fruiting period: from colonization to initial fruit, the task of plastic pruning is to form a reasonable and solid skeleton and rapidly increase the amount of branches. It not only pays attention to shaping and expanding the canopy, but also promotes early fruit and early production as soon as possible. A reasonable skeleton should be carefully cultured from after colonization. The fixed dry height is controlled between 60cm and 80cm, and the mountain can be slightly lower, and the flat principle is slightly higher. In the year of dinggan, it is necessary to strengthen the fertilizer and water management to promote branching, so that 4-5 high-quality strong branches will be issued that year. If the main trunk is thinned, the first branch in the middle can be selected as the central stem, and the rest should be selected from 2-3 branches in different directions, pulled out the angle, and cultivated into the main branch. Since then, the central trunk and main branches have been shortened year by year, and the second and third layers of main branches and the side branches on each main branch have been cultivated, forming a strong skeleton with strong support ability and ventilation and light transmission.
If the second layer of culture is delayed, the 1-2 branches growing at the top need to be pulled to a 70-80 degree angle when they grow to 40-60 cm. Promote the lower branches to grow strongly, to the middle and late July when the extension branches are close to the stop length, all pulled into an angle of 80-90 degrees, the winter shearing is heavy and short, the thin and weak branches that grow only 10-20 cm are on top, "the crown is expanded", the summer continues to pull the main branches into an 80 degree angle, forming a happy shape, and cultivating some branches into fruit branches, to the fourth year on the basis of happiness, with the middle stimulation germination of the second layer of the canopy, so that the layer spacing reaches 1.5m, and the second layer of the main and side branches are pulled into a happy shape, A skeleton that forms a two-layer delayed happy shape.
2, the pruning characteristics of the tree at the fruit stage: after the hawthorn enters the fruiting stage, its canopy is in a stable state, and the pruning task in this period is to continue to adjust the subordinate relationship of the backbone branches, create a good tree structure, and promote the robust growth of the branches; alternately update the fruit branch group and retract the long fruit branch group.
Pruning methods should be mainly based on thinning fruiting branches and retracting large branches, supplemented by short and thin weak branches. Sawn or retracted perennial densely squeezed branches, overlapping branches, crossed branches, especially large branches in the south, that have caused serious deterioration of intracorular light and poor ventilation. Adjust the skeleton, correct the partial crown, improve light, concentrate nutrients, and promote the robust growth of branches. For the extension of the main side branches, depending on the specific situation, or shortened at the strong bud, so that the canopy can continue to be expanded; or the back branches are used to change their heads to prevent the outer branches of the canopy from being densely crowded; for the resulting mother branches of the peripheral photo-bearing ring layer, it should be done to be weak and strong, and to support the moderate; it can also take the method of thinning branches, so that the two are left in every three cuts, and the short cut is prepared as the resulting mother branch of the second year. For the mother branches that have shown senescence for several years of continuous results, retract to the strong buds to maintain the robustness of the fruiting mother branches; for the weak branches in the inner chamber, they are restored in time and finely pruned. Make full use of the long branches emitted by the bare band inside.
In the late stage of fruiting, the management measures are not effective, and it is easy to have large and small annual results, which need to be adjusted through pruning on the basis of strengthening the management of soil fertilizer and water. In large years with a large amount of flowers, it must be finely pruned, and the branches that bear fruit on the backbone branches should be removed as much as possible; for the auxiliary branches and large branches, the rear branches should be updated to be pruned, leaving the results of the front branches, and then retracting to the new part when the winter pruning is after the fruit. In this way, the yield of large annuals can be reduced and the resulting site can be prevented from moving outward. For small fruiting branches, the method of rotating results is adopted, that is, half of the branches are processed. The other half of the shoot cut off the mixed bud and did not bear fruit, and then changed the result the following year. For trees with a large amount of flowers, it is necessary to control the amount of flowers, remove the weak mother branches on the twig group, and cut 1-2 mixed buds from the top for the resulting mother branches with 2-3 full mixed buds, so that the whole tree has an appropriate amount of flowers and a reasonable load. After the mixed buds germinate, when the amount of flowers is still too large, they can be combined with sparse flowers to remove some of the inflorescences or flowers.
In the formation of small years with small flowers, mixed buds should be retained as much as possible in winter shearing, and only the extension of the short-cut backbone branches should be shortened. For annual branches that may be mixed buds, they are re-pruned after buds are present, and the flower branches are retained and the thin branches are retained. On the basis of strengthening the fertilizer water, it will be adjusted year by year.
3, the pruning characteristics of the senescent tree: hawthorn into the aging stage, that is, the occurrence of scorched shoot phenomenon, the result of the mother branch is mostly thin three types of mother branches, flashy and unrealistic, the number of inflorescence fruits is small, the yield is greatly reduced. The pruning of this period should make full use of the long life of the latent buds of hawthorn and give timely renewal and retraction. The retracted renewal of the backbone branch depends on whether there is a "tumor" on the backbone branch, or whether a new branch has been born, if it has appeared, it can be sawn off in the upper part; for the aging tree that is endangered by the gidding insect, the insect needs to be treated before updating, otherwise, the update will accelerate the death of the hawthorn tree. The amount of renewal of the hawthorn canopy should not be too large at one time, and can be renewed in 3-4 years. The renewal of the branch group should also be rotated and carried out in separate years, and the update site should be selected in the branches of about five years, and the annual renewal volume accounts for 1/3 of the whole branch group, and a renewal pruning cycle is completed within three years. For the renewal of old trees, we must strengthen the management of fertilizer and water, pest control and the protection of saws, otherwise the update effect is poor, and even aggravate the bare branches and defects.