The number of branches is an external sign reflecting the growth results of trees. Insufficient branches will lead to vigorous growth of trees, insufficient branches, low yield, low economic benefits, or the phenomenon of bearing fruit in different years; However, if there are too many branches and the tree is weak, although it is easy to blossom, it is easy to bear fruit in different years because of lack of nutrition, low fruit setting rate and poor quality. Only by maintaining the proper number of branches per plant and branches per 667 square meters can we maintain a robust tree and maintain high quality, high yield and stable yield.
The suitable number of branches per plant and the number of branches of 667 square meters often vary with different tree species, varieties and tree ages. For high-yield apple orchards with a yield of about 60,000 ~ 75,000 kg/ha, the suitable number of branches per hectare is about1.50,000 ~ 2.25 million. The total number of branches of young fruit trees is small, but it grows rapidly; After entering the full fruit stage, the total number of branches increased and was relatively stable; After the trees enter the aging period, the growth potential is gradually weakened, and the total branch quantity and yield are also reduced year by year.
The number of branches is not only related to tree species and varieties, but also affected by site conditions, nutritional level and pruning techniques. The appropriate number of branches is an important factor to form a high-yield tree structure, and it is also the basis for high quality, high yield and stable yield.
The number of branches of fruit trees has obvious influence on the growth potential of the upper and lower parts of main branches and the strength of late-comer advantage. If there are too many branches, the branches at the lower part of the main branches are weak, and the fruiting ability is poor, which is easy to die; When the number of branches is too small, the middle and lower branches of the backbone branches grow vigorously, the advantages of the back are obvious, the vegetative growth is too strong, and the yield is low and unstable.
The relationship between the number of branches and the total number of branches is generally complementary, that is, with the increase of the number of branches, the total number of branches also increases accordingly. When pruning, you can balance the tree potential by adjusting the total number of branches and the number of branches, or you can balance the tree potential by adjusting the main branch, upper branch and two branches.
When the number of branches and the number of branches are large, more branches sprout from long branches, and the proportion of medium and short branches is also high. When the number of branches and the number of branches are small, the germination ability of branches is also poor, and the proportion of medium and short branches is also low.
Because the number of branches is closely related to the growth of fruit trees, attention should be paid to increasing the number of branches for varieties with high germination rate and weak branching ability when pruning; For varieties with low germination rate and strong branching, attention should be paid to increasing the number of branches; For young trees, it is necessary to cut long and leave many branches, increase the number of branches and promote early flowering and early fruiting; For fruit trees in full fruit stage, the number of branches should be controlled to keep the tree vigorous, prolong the fruiting period and obtain higher economic benefits.
The branching angle has an important influence on crown enlargement and early fruiting. Generally, the branch angle is large, which is beneficial to crown expansion and early fruiting; Small branching angle is not conducive to expanding the crown and delaying the fruiting period. Among apple varieties, Redjade, Alcoholic Dew, Xu Xu, Mannan, Golden Crown and Green Banana have larger branching angles. Guoguang, Zhuguang, Yingqiu, Yuan Shuai, Fuji, Qiuhuapi, Huang Kui and other varieties have small branching angles (Figure 7).
Fig. 7 branch angle
1. Large branch angle 2. Small branching angle.