(1) Orchard pruning should be tailored to local conditions, and don't blindly follow suit.
As early as 1950s, China was in the great development period of Apple. In the 1970s and 1980s, what kind of trees to plant was the first problem to be solved. On the basis of investigation and experimental research, fruit tree workers in various apple producing areas in China put forward various tree types such as small bend semicircle, cross, three-legged open, open, open, open, open, open, open, open, open, open, open, open and so on. Every tree has high yield examples. After several years of debate and research, everyone has reached a consensus that all kinds of trees can produce high yield and high quality, but they all have a common feature, that is, trees should have "low stems and short crowns, few main branches and many sides, rationally equip bearing branches and make full use of supporting branches". Simply put, there are fewer big branches and more small branches. "It's bright from a distance and noisy from a close look." Today, these * * * are still the principles that we should seriously follow.
However, due to different soil climate, different fertilizer and water conditions, different managers' levels and different original tree foundations, it is not appropriate to take out a tree that is considered to be the best for thousands of families to imitate and make major changes. Managers with a higher level can understand the characteristics of new trees and will not cause losses, while managers with a lower level may cut and imitate them mechanically. Finally, the tree looks beautiful, but the output is greatly reduced, and the benefits are naturally out of the question. Some orchards have a good foundation. After the transformation, the yield decreased slightly, but the proportion of high-quality fruits increased and the benefits also improved. But in some orchards, the trees are scarred and the branches are sparse, which is close to destroying the orchard. There is no yield, let alone quality. Therefore, we should carefully observe and study the orchard, solve any problems, don't blindly follow the trend, and follow the original deployment step by step if there are no problems.
(2) Tree changes in different periods.
The cultivation of tree is a dynamic process, that is, in production, the tree used is not static, but will change with the growth of tree age and the expansion of crown. This is not only the improvement of production technology, but also the deepening of understanding of the objective world and the change of adapting to market requirements.
Generally speaking, under the normal growth of trees, before the first fruit period, that is, before 7-8 years old, trunk type or free spindle type can be adopted, and more small main branches can be arranged on the upright trunk of the central leadership, up to 12- 15. After entering the full fruit stage, it gradually changed into the form of evacuation and stratification, that is, three main branches were defined at the height of 80- 100 cm, and two main branches were left on the three main branches at 100- 120 cm as the second main branch, and the middle branch was compressed into a supporting branch, and one was left on the second main branch at 50 cm. In another 7-8 years, according to the lighting conditions, it will be gradually transformed into a two-layer happy type, leaving five main branches, or a happy type, leaving three main branches. If the planting method of large row spacing and small plant spacing is adopted, it will be changed to a fan shape of 2-2- 1- 1 after the full fruit period, and then changed to a double-layer jubilation or a main branch jubilation of 2-2. This planting method is beneficial to mechanized farming between rows.
Winter pruning and summer pruning should pay attention to the cooperation of plastic pruning technology, and on the basis of strengthening fertilizer and water management, it should be coordinated with a series of summer management such as pest control.