The permanent branches that make up the crown skeleton are called main branches, including central trunk, main branch and side branches.
The permanent big branch extending upright from the trunk and located in the center of the crown is called the central trunk, which used to be called the central leading trunk or the central leading trunk; The central trunk of dense planting is very small, similar to a big main branch, in the central position, so some people call it the central main branch. The central trunk of the trunk shape is changed into a curved extension by pruning measures.
The permanent branches directly connected to the trunk are called main branches. The permanent big branches attached to the main branches are called side branches.
There are many branches on the main branches and auxiliary branches, which can be divided into vegetative branches and fruiting branches according to their properties. Vegetative branches grow leaf buds, new branches, and constantly expand the crown to form fruiting branches or fruiting branches.
Trunk, backbone branches, auxiliary branches, and vegetative branches and fruiting branches (fruiting mother branches or fruiting branch groups) planted on the backbone branches and auxiliary branches form the tree structure of fruit trees.
The big branches planted between the layers of the central trunk and the upper branches of the main branches are auxiliary branches. The function of auxiliary branches is to support the tree, balance the tree potential and promote the fruit. When the main and lateral branches can't recover due to pests or accidental injuries, auxiliary branches with better planting positions can be cultivated according to the requirements of the main and lateral branches to replace the original main and lateral branches. Auxiliary branches are divided into short-term auxiliary branches and long-term auxiliary branches.
When the short-term auxiliary branch occupies the terminal space of the main branch, it is used to temporarily supplement the space, increase the fruiting position and assist the growth of the main branch. The fruit-bearing parts of young trees are mainly on the auxiliary branches, and whether the auxiliary branches are used properly directly affects the yield of young trees. Short-term auxiliary branches occupy less space. Short life, the main task is to promote the overall growth and early fruit, no extension.
Long-term auxiliary branches are located in parts with sparse main branches and room for development. Large space occupation and long service life. If it fails, it can help maintain health and accelerate the expansion of the crown. After fruiting, it is used to bear fruit and assist growth, and sometimes it can replace the original main side branches.
"Stem" refers to the ability of fruit trees to form their own central trunk and maintain its growth potential. If the ability to form a central stem is strong and the growth advantage is easy to maintain, it is called "strong dryness"; On the other hand, the ability to form the central stem itself is weak, and the growth advantage of the central stem is not easy to maintain. It is called "weak stem", and its drying degree varies with the types and varieties of fruit trees, such as apple trees and pear trees, peach trees and plum trees. Compared with different varieties of apple trees, Jinguan and Guoguang have stronger dryness, while green bananas have weaker dryness. When shaping, trees and varieties with strong dryness should adopt the tree shape in the center of the trunk; For those trees and varieties with weak dryness, happy trees are often used.
When pruning, we should pay attention to controlling the growth of the upper part of the crown and the varieties with strong dryness, and control the competitive branches in time to prevent the phenomenon of "strong on the top and weak on the bottom". For weak and dry varieties, it is necessary to pay attention to not leaving too many branches at the base, to increase the angle and control the growth potential of the branches at the base, so as not to affect the growth potential of the central trunk and prevent the phenomenon of "strong below and weak above". For split heart-shaped trees, attention should be paid to local regeneration and the cultivation of fruiting branches to avoid premature aging.
"Stratification" is the ability of branches to naturally stratify in the crown. The obvious stratification is called "strong stratification", and the inconspicuous stratification is called "weak stratification". Stratification and tree species. The branching ability of varieties is related, and the stratification with strong branching ability is also strong. In the period of tree species and young trees, stratification is obvious; After entering the full fruit stage, stratification weakened. For tree species and varieties with strong layering, it is advisable to use tree trunk thinning to prevent the interlayer spacing from being too large; However, the tree species and varieties with weak layering should be shaped with open heart.
When the weak trunk of the layer is sparse, it is necessary to control the auxiliary branches between layers not to be too large, maintain a large leaf curtain spacing, and control the thickness of the leaf curtain to facilitate ventilation and light transmission. In densely planted orchards, because the crown diameter is reduced, the light transmission in the crown is better, so it is not necessary to emphasize the stratification of main branches, such as cylindrical and spindle crowns, and the main branches can be inserted and arranged, which is not suitable for rigid stratification.