The transformation principle of strong and weak trees of fruit trees is to suppress the top and promote the bottom, and the key is to control the dryness and top advantage of all kinds of backbone branches above the central trunk reasonably.

1. Reasonable close planting and scientific shaping: In order to prevent the upper strength from weakening, two technical problems should be paid attention to during the shaping of young trees. First, reasonable close planting should ensure the growth space and ventilation and light transmission conditions of the lower main branches, and thinning should be carried out in a planned way for those with too small plant spacing. Second, for varieties with strong stem and tip advantages, the three main branches in the lower layer should be arranged in an adjacent way, and the main branches and lateral branches above the central trunk should be cultivated in a bending and stretching way, and if necessary, the techniques such as girdling, girdling and stripping should be used to control them properly.

2. Transformation of the big tree: the strong branches of the main branches and lateral branches are taken back above the central trunk, the weak heads are replaced, and the "bare legs" and weak branches below the branch axis are carved and peeled for many times to promote more fruits, so as to disperse the strength and slow down the front and promote the back. For the lower main branches, the angle should be raised appropriately, and all the flowers and fruits on the inner branches should be thinned out in the first three years. The lower fruiting branch group should reduce fruit and cut branches appropriately, and restore its growth ability by promoting some vegetative branches. The auxiliary branches between the upper layers of the central trunk should be properly drained, and the weak branches on the back should be reserved for retraction if they are too dense, and girdling should be controlled in summer; You can also twist the branches in the middle and lower parts, and fix the branches into a drooping shape by twisting 180 degrees. For all kinds of rotating fruit trees whose main branches are not layered, the key point is to control the middle and upper main branches by retraction and girdling.

Adjustment and transformation of strong trees and weak trees