Detailed Explanation of the Key Points of Shaping and Pruning Techniques for Young Goji Berry Trees

Goji berry trees generally enter the young tree stage 4-5 years after planting. At this time, the tree body grows vigorously and has a strong branching ability. If the branches are pinched back, they can sprout branches three or four times within a year. The shaping and pruning of young trees is mainly focused on shaping, selecting and retaining strong branches to cultivate the tree crown framework, gradually expanding the tree crown, cultivating branch groups, and increasing fruiting branches. In the selection and cultivation of tree shape, flexible adoption should be made according to cultivation conditions, with the principle of favoring high yield, laying the foundation for future high yields. Although there are many tree shapes for goji berry trees, the principles of shaping and pruning are basically the same; only the number of main branches and the number of layers differ among tree shapes. Now, taking the conical shape as an example, the shaping and pruning methods for young trees are introduced as follows.

In the first year, the trunk is headed. The heading height varies with the size of the seedling. Thick and strong seedlings are generally headed at a height of 60 cm, while weak and slender seedlings are headed lower. If the heading is too low, the fruiting branches produced will rest on the ground, damaging the flowers and fruits and making cultivation inconvenient. If the heading is too high, the center of gravity will be unstable, and the tree crown will easily tilt, affecting branch distribution, crown area, and yield. Generally, in the year of planting, the top is cut and the trunk is headed at 50-60 cm above the ground. In the new branches produced within 10-15 cm below the cut in the year of heading (if there are original side branches on the main trunk, they can also be used), select 4-5 strong branches evenly distributed around the main trunk as the first layer of main branches, and cut them back at 10-20 cm to make them branch. At the same time, 3-4 small branches can be selected and retained on the upper part of the main trunk without cutting back, becoming temporary fruiting branches, which is beneficial for shaping while fruiting. Excess branches on the main trunk should be cut off. After the main branches produce branches, select 1-2 branches on each side of them as first-level large side branches, and pinch or cut them back at 10 cm (if the branches are weak in growth, do not cut them back that year; this task can be carried out the next year).

In the spring of the second year, if the branches produced by each main branch the previous year were not cut back that year, then in the second year, 1-2 branches should be selected on each side of each main branch and cut back at about 10 cm to make them branch, cultivating them into fruiting branches that flower and bear fruit. At the same time, if the temporary fruiting branches retained on the main trunk in the first year are too weak or too dense, they can be thinned out. In the second year, because the tree vigor increases, relatively upright water sprouts will be produced from the back of the main branches selected and retained in the first year. One can be selected from each as an extension branch of the main branch and pinched at 10-20 cm. After the extension branch produces branches, similarly select 1-2 branches on each side of it and pinch them at about 10 cm to make them branch again and cultivate them into fruiting branch groups. If upright water sprouts are produced on the upper part of the main trunk, select one branch and pinch it at 10-20 cm above the crown surface to cultivate it into a central leader. When it produces branches, select and retain 4-5 branches as the second layer of main branches. If this main branch grows strongly, it can be pinched (cut back) at 10-20 cm to promote branching to form the tree crown. If this main branch grows moderately, the cutting back task can be carried out the next year. For branches that affect the growth of the main branches, methods such as propping or pulling can be used to spread the branches evenly so as to produce branches and form a full tree crown. Weak branches that are too dense and crossing branches, etc., should be cut off.

From the third to the fifth year, following the method of the second year, water sprouts are pinched and utilized to gradually expand and fill out the tree crown. If an upright water sprout is produced at the upper end of the central leader, select and retain three branches and pinch (cut back) them at 10-20 cm above the crown surface. If no water sprout is produced at the upper end of the central leader, then on the upper-layer main branches or their extension branches, within 15-20 cm above the central axis of the crown, select 1-3 upright water sprouts, also pinching (cutting back) them at 10-20 cm above the crown surface, to produce side branches and increase the height of the tree crown.

After 4-5 years of shaping and pruning, the tree height generally reaches about 1.6 m, the crown diameter is about 1.0 m, the root crown thickness is 5-6 cm, and a 4-5 layer tree crown framework is basically formed. However, if fertilizer and water are insufficient, cultivation and management conditions are poor, and the tree body grows weakly, then branches cannot be produced on schedule or the branches produced are relatively weak; then the formation time of the tree crown will be delayed. If upright water sprouts cannot grow on the upper part of the main trunk, a tree shape without a central leader will be formed.