(1) young tree pruning
In this period, pruning methods such as fast-growing trees, rapid crown expansion and early fruiting should be adopted. Generally, it takes 2 ~ 4 years for grafting trees and 4 ~ 7 years for seedlings. In order to quickly grow trees, expand crowns and form more branches and leaves, in the first winter after planting, we should appropriately cut more branches, and then put them slowly to promote the early formation of flower buds, so that flowers and fruits can be seen in the third and fourth years. At the same time, strengthen the management of fertilizer and water, so that trees can grow rapidly, expand their crowns quickly and take shape as soon as possible.
That is, in this way, there will be a considerable output in 4 ~ 5 years, and it will take shape in about 7 years. Some varieties that start to bear fruit late and grow vigorously, such as Zaomeisu, Zhongli 1, Huasu, etc. , should girdle, pull branches open angle, make it bear fruit at an early date. For densely planted trees, these measures should be taken.
(2) Pruning trees at the initial stage of fruiting
At this stage, the crown has not yet formed, and it is still in the stage of synchronous growth and fruiting. Therefore, in this pruning period, we should prune, plant trees, expand the crown and shape, and bear fruit. It is one of the common pruning measures in the early stage of fruit to leave more trees and put more trees or cut them first and then put them. In the process of crown expansion and plastic surgery, it is not advisable to leave too many fruits, but to leave room. As far as a branch is concerned, it is determined that it will eventually be thinned, and it should be fully extended and thinned after the fruit is produced. If it is determined that it is cultivated into a twig group, it should be put more appropriately to make it shrink after bearing more fruits. We should make way for the main branches year by year, and the big auxiliary branches should be retracted year by year. According to the development of boughs, when they are used, they should be put away, and sometimes even put away. However, when cultivating large and medium-sized branches, we should try our best to make them bear less fruits, put less flowers and cut more, ensure strong branches and buds, and make them quickly expand their crowns and take shape. For example, in the weak branch group and the branch group that needs to change from small to large, the branches should be stocked for a long time, so as not to bear fruit, and then the branches should be shrunk and pruned after strengthening for one or two years. On the contrary, strong branches are cut first and then put, and the branches made after cutting are shorter. In the crown with more scattered branches, according to the arrangement of backbone branches, gradually select large and medium branches and leave them. However, with the arrangement of large and medium branches, branchlets are kept at will, and unnecessary dense branches or twigs are gradually sparse.
Pear trees are easy to blossom, and can generally bloom after long-term planting, but pear trees have few branches, so in the early stage of fruiting, fruit yield should be limited to ensure the increase of branches and leaves. In the process of plastic surgery, the amount of branches and leaves should be increased rapidly. However, on the basis of sufficient branches, it is not advisable to let go of too many long branches and cut off too many short branches.
(3) Pruning of trees in full fruit period
For trees with heavy fruits, the following pruning methods should be adopted:
(1) After the trunk branches at all levels are closed in full fruit stage, especially in close planting, the branches tend to tilt upward, resulting in strong front and weak back, and the inner cavity is exposed early. Therefore, after the crown is closed, no extension branches can be left, and the top branches can be replaced by oblique branches under the extension branches. In order to prevent the former flourishing, the branches can be properly thinned at the flourishing place, and the branches with large opening angle can be changed into extended branches, or the fruit hanging amount can be increased to control. If the fruit is hung in front of the main branch during the full fruit period, the branch will gradually droop and its growth will be weakened. In this case, the inclined upper branch can be changed into an extended branch to improve the angle. You can also use the oblique branches that naturally appear at the back of the arch frame after the main branches droop, and cultivate them to extend outward to the main branches and the original drooping parts to increase the yield. When the reaction of new buds in the inner chamber is weak, it shows that the inner chamber is malnourished, the main branches extend too far, or there are too many fruits in the back or too many branches in the front. It is necessary to distinguish the reasons and overcome them. To retract properly, the nearby branches should be properly matched with shrinking scissors and short scissors. If the vertex angle is small, adjust the vertex angle. In short, it is to make the main branch have many effective branches, which are evenly distributed and have equal internal and external potentials. For the branch group, we should continue to cultivate, pay attention to the number of fruiting branches and the amount of fruit hanging in the branch group, and do not exceed it. To leave enough branches, respectively, appropriate pruning. The mother branch should be renewed after 6-8 years of fruiting. It is necessary to pledge strong branches and strong buds to promote the development of new branches every year. It is necessary to plan and arrange branches well, use light shrinkage, short cutting of fine branches, and appropriate cutting and putting more, so as to keep the growth and fruiting relationship between branches in harmony and maintain lasting production capacity. Pruning is generally used in the full fruit period, such as cutting more fruits in the inner room, stocking the weak branches, cutting them again, thinning the periphery a little, and leaving more fruits in the middle and front. The prepared new shoots reserved at the back should be cut short in batches, and each new shoot should be cut off to ensure a certain number of new shoots every year for use when replacing the aging branches in the inner room. In particular, branches that are not easy to renew and rejuvenate themselves must be supplemented by long branches nearby, and more attention should be paid to retaining new branches. The pruning reaction of pear trees is not as sensitive as that of apples, and it is generally not easy to run. Pear trees are planted for a long time and will bear fruit soon. Short cuttings can be turned into branches.
(2) When pear trees enter the full fruit stage, the pruning amount is generally not large, and three sets of branches are mainly pruned to keep flowers and fruits. For trees that are easy to bear fruit every year, we should pay attention to the turnover of bearing branches, keep them strong and weaken. For varieties with short fruit branches that are easy to grow into flowers and leaves, leave strong flower buds to bear fruit, cut off other flower buds, or sparse inflorescences and leave leaves when flower buds are separated in the next year. All dead branches and twigs should be pruned.
(3) Pear trees with full fruits are easy to form flower buds. For trees of all ages, almost all varieties have flower buds on young, old, middle and short branches. If the number of short branches is sufficient and the turnover is sufficient, they should be cut from the long and middle branches of axillary buds, especially the head branches. Under normal circumstances, flower buds should be peeled off and cut off to ensure the growth of branches. Due to the limitation of nutrient distribution, fruits should not be concentrated on several big branches, and fruits should bear fruit in turn among branches. If the parts are too concentrated on one or several big branches, it will inevitably hurt branches and trees, resulting in low yield, small fruit and poor quality. So be sure to make the results evenly distributed.
(4) Pruning of trees at the later stage of fruiting.
At this stage, the whole tree is in a transitional period to the aging stage. Although pear trees can bear fruit, because of their relatively weak growth potential, the absorption and assimilation function is reduced, and there will inevitably be many flowers, few fruits and poor quality. This is what people usually call "full of flowers and half fruit". Because the fruiting branches are gradually aging, it is difficult to renew, and there are many weak branches, the pests and diseases are more serious. Therefore, it is necessary to take pruning measures to limit production, improve quality, renew and rejuvenate on the basis of strengthening the comprehensive management of soil, fertilizer, water and pests. When pruning in winter, the backbone branches and branches that migrate outward from the fruiting parts should be taken back for pruning, and the strong branches on the back should be used as collateral. At the same time, the delicate branches with more flower buds should be loosened, the work of flower thinning and fruit thinning should be strengthened, and the fruit yield should be strictly controlled to ensure the improvement of fruit quality on the basis of basic normal yield. For the vigorous branches in the chamber, they should be cut short at the full buds in the middle and lower parts and gradually cultivated into fruiting branches to replace the gaps formed by the loosening of some backbone branches. During this period, we should pay attention to renewal and rejuvenation, strictly limit the load and prolong the bearing life.
(5) Pruning of aging trees
Aging is the last stage of the life cycle of fruit trees. Usually take the old place to narrow the pruning method. In order to strive for the speed of renewal and rejuvenation, preparations should be made before renewal, such as deep ploughing the soil; Apply a lot of base fertilizer; Proper control of fruit hanging; Leave more branches and leaves; Thereby enhancing the nutrient accumulation of trees. In addition to the retraction and renewal of the main branch, the branches of other related parts are also shortened. For the new branches after aging and rejuvenation, flower buds will form soon, so it is necessary to control them properly so as not to affect the recovery of tree potential, and then make them bear normal fruit after rejuvenation.