Detailed Explanation of the Trunk-Tiered Training and Pruning Method for Goji Berry

Goji berry, also known as West goji, mountain goji, white thorn needle, and goji thorn, is a plant of the Solanaceae family. In Ningxia, the goji fruit is used as medicine and called "goji berry," while the root bark is called "digupi" in traditional Chinese medicine. Goji berry has the function of nourishing the liver and kidneys and improving eyesight, while digupi has the function of removing dampness and cooling the blood. Goji berry is mainly produced in Ningxia, and is also produced in Hebei, Gansu, Qinghai, Inner Mongolia, Shaanxi and other places. It is a precious medicinal material famous at home and abroad. Goji berry has strong branching ability and vigorous growth, with a habit of flowering and fruiting twice a year, and grows quickly. After 5a it can enter the full fruiting period. After 30a the tree shape gradually weakens, and after 40-50a the tree vigor ages. Therefore, improper and unreasonable training and pruning will cause aging in about 20a. Therefore, reasonable training and pruning is an important measure for high and stable yields of goji berry. Based on many years of growing practice, the main characteristics of goji berry and the trunk-tiered training and pruning method are introduced as follows.

1 Main Characteristics of Goji Berry

Goji berry is relatively cold-tolerant, drought-tolerant, and salt-alkali-tolerant, with very strong adaptability, and is not limited by temperature, soil quality, or terrain. It prefers sunlight; although it can grow in shaded environments, fruit yield is low. It prefers water and fertilizer, but well-drained, fertile, neutral sandy loam is best. Paddy fields and low-lying waterlogged land are not suitable for planting. It is mainly propagated by seed, and can also be propagated by cuttings and division.

2 Trunk-Tiered Training and Pruning Technique for Goji Berry

The purpose of training and pruning is to cultivate a stable, full tree shape with a large fruiting surface, improve ventilation and light conditions, regulate the relationship between fruiting and growth, and achieve high yields year after year. Production practice has proven that the "trunk-tiered" training and pruning method is the most ideal for goji berry. The tree height is set at 1.5-2.0 m, and the average crown diameter is 1.6 m. The main branches are distributed in 3 tiers on the central leader, with a certain spacing between the tiers. This tree shape has good structure, is convenient to manage, and can bear fruit earlier. The specific method is as follows.

2.1 Training of Young Trees

2.1.1 Trunk Determination After planting, in spring, cut the top at about 60 cm above the ground to determine the trunk.

2.1.2 Training the First Tier of Main Branches After trunk determination, from the new lateral branches (or existing lateral branches) that emerge within 10-20 cm below the cut, select 3-5 evenly distributed branches to keep as the main branches for training the first tier of the crown. In the same autumn or summer, cut back each main branch to a length of 10-20 cm. The following spring, new lateral branches will emerge from each main branch. For vigorous ones, cut the top in summer or autumn at 20-30 cm, and appropriately thin out weak branches. In the 3rd year, newly emerged lateral branches are generally not cut back, allowing them to gradually expand and fill out the first tier of the crown.

2.1.3 Training the Second Tier of Main Branches In the 2nd year after planting, from the upright water sprouts emerging from the upper part of the trunk, select and keep 1 as the extending trunk, cut the top at 120 cm above the ground, and from the lateral branches emerging from the top, select and keep another 3-5 as the main branches of the second tier of the crown.

2.1.4 Training the Third Tier of Main Branches In the 3rd year after planting, from the upright water sprouts emerging from the center (top) of the second-tier crown, select and keep 1 as the trunk, cut the top at about 160 cm above the ground, and from the new lateral branches emerging near the top, select and keep 4-5 as the main branches of the third tier of the crown.

Within 4-6a after planting, the main task is to expand and fill out the crowns of each tier and promote thick growth of the trunk, preparing for entering heavy fruiting. During this period, overly dense branches and excessively vigorous branches should be controlled by thinning, pinching, or cutting back.

2.2 Pruning of Mature Trees

Mature trees refer to goji berry trees that have begun heavy fruiting after growing for 5-6a. Pruning work can be carried out in spring, summer, autumn, and winter, and the main purpose is to continuously renew fruiting branches to achieve high and stable yields.

2.2.1 Spring Pruning During bud break to the early stage of new branch growth, cut off dead branches, crossing branches, and root suckers.

2.2.2 Summer Pruning Summer pruning is carried out from May to June, cutting off water sprouts, overly dense branches, weak branches, and diseased and insect-damaged branches on the trunk or lateral branches that do not need to be retained, so as to reduce nutrient consumption and promote fruit growth and development. However, water sprouts in gaps or bare areas within the crown should be retained, and their tops should be cut when they reach the desired height.

2.2.3 Autumn and Winter Pruning Autumn and winter pruning is carried out from August to November. Remove water sprouts sprouting from the base of main branches; cut off upright water sprouts at the top of the crown to keep the crown at a certain height; remove old and weak branches inside the crown to enhance ventilation and light penetration inside the crown; carry out pruning around the crown by removing the old and keeping the new, cutting off old and weak branches, horizontal branches, diseased and insect-damaged branches, water sprouts, thorny branches, etc., and cut the tips of some old branches, selecting and retaining healthy fruiting branches (including the current year's "seven-inch branches" and "old-eye branches"), to lay a good foundation for a high yield the following year.