Pruning cherry trees mainly includes two pruning periods: winter pruning and summer pruning. In different pruning periods, the tasks and methods of pruning are different, and the results are also different. Generally speaking, summer pruning is also called growth pruning, which mainly refers to coring in the growth period of new shoots and draining or shrinking the fruit after picking. The purpose is to inhibit the vigorous growth of new shoots, promote the growth of branches, increase the number of branches and ensure the differentiation of flower buds. Winter pruning, also called dormancy pruning, is mainly to keep the balance between normal growth and fruiting of cherry trees, adjust the primary and secondary relationship of backbone branches, make the tree have a reasonable fresh structure, build various fruiting branches, and lay a solid foundation for high yield.
Although the pruning of cherry trees can be divided into two periods: winter pruning and summer pruning, if cherry trees are pruned in winter, it is usually after defoliation and before germination, which is easy to cause shrinkage, gum flow, consumption of a lot of water and nutrients, and even death of big branches. Therefore, the pruning task of cherry is mainly completed in summer.
Compared with winter pruning, summer pruning of cherry trees has the following advantages: first, the incision is easy to heal and not easy to die; Second, pruning in summer dwarfs the trees, stabilizes the tree potential, and can use the space more effectively; Thirdly, because the overgrowth of trees is inhibited, the blight caused by Verticillium dahliae is eliminated, and the bacterial gummosis that harms trees during dormancy is inhibited; Fourth, the amount of branches and leaves increased, which promoted the formation and early fruiting of flower buds.
Although in most cases, the pruning and shaping of cherries have been completed in summer, the importance of pruning in winter can not be ignored. However, winter pruning needs to master a certain degree of heat, especially in the grasp of time, because if the time is not well grasped during this period, it is easy to cause glue flow. The dormancy period of cherry generally starts from the middle and late of 1 1 to March and April of the following year, and lasts for 140- 1.50 days. During the whole dormancy period, the later the appropriate pruning time, the better, and it is best to prune near germination in the middle and late March. The earlier the pruning time, the longer the wound will lose water, and the glue will flow easily in the second spring, which will affect the growth and even lead to the dead branches in serious cases.
For cherry pruning, cherry tree pruning at full fruit stage is the most common. Let's talk about the characteristics of cherry tree pruning in the full fruit period. Generally speaking, under normal circumstances, cherry trees can enter the full fruit stage after 7-8 years of planting. This period is characterized by rapid growth of output and gradual decline of growth. Therefore, pruning in full fruit stage is mainly to adjust the tree structure, improve the lighting conditions, keep the tree vigorous and prolong the full fruit year.
After a large number of fruits, the tree potential and fruiting branches gradually weakened with the growth of tree age, and the fruiting parts moved outward. Therefore, in the process of pruning, we should always pay attention to thinning weak branches and retaining strong branches. Adjust the balance between growth and fruiting, keep a large number of new shoots growing and an appropriate number of fruiting branches and vegetative branches, and constantly update the rejuvenated and aging fruiting branches, so as to keep more effective fruiting parts in the crown. For the big branches that grow vigorously, and the perennial branches that affect the tree shape, the back is bare and the fruit moves outward, the branches can be thinned or shrunk after picking.
For vigorously growing main branches and lateral branches, when they grow to 40-50 cm, one-third to one-quarter of the top can be cut off; For the extension branches with moderate growth, if the growth is normal and the annual growth does not exceed 20 cm, it is not necessary to cut them short. When cutting extended branches, you must leave leaf buds, not flower buds, in case you don't pick branches after the fruit, which will affect the crown expansion.
The branches that droop all the year round in the crown, as well as the weak and aging branches, should pay attention to renewal and rejuvenation, and can be shrunk to good branches, and pay attention to improving the branch angle. Promote the growth of trees; At the same time, measures such as removing the weak and retaining the strong, leaving the far and staying close, and replacing the old with the new are taken to upgrade. We should also pay attention to increasing the proportion of leaf buds in the branches, maintaining normal growth and fruiting ability, delaying the outward migration of fruiting parts and preventing the cavity from being empty. For the fruiting branch group that has been fruiting for many years, the branches can be shrunk at the top of the branch group at the age of 2-3 years to promote the growth of branches, enhance their growth and restore their fruiting ability.
When pruning, we must pay attention to moderate harvesting, so that harvesting is not strong, and throwing is not weak, in order to achieve the purpose of more fruits, good quality, high yield and high quality.