Detailed Explanation of Key Techniques for Trellis Management in Schisandra Cultivation

Schisandra, also known as mountain pepper or Liaoning schisandra, has fruits that can be used not only for medicinal purposes but also for brewing wine and making juice, making it a plant species with both medicinal and edible uses. In recent years, demand has been continuously growing, and reliance on wild resources is far from sufficient to meet people's demand for schisandra raw materials. The quality of trellis management has a significant impact on the high and stable yield and quality of cultivated schisandra. The trellis management techniques under cultivated conditions for schisandra are described below:

Trellis types for schisandra

Schisandra is a perennial climbing vine plant with slender and soft branches and vines that need to twine clockwise around other supports to grow upward. Therefore, under artificial cultivation conditions, trellis poles need to be set up so that schisandra maintains a certain tree form, and branches and leaves can be reasonably distributed in space, thereby obtaining sufficient light and good ventilation conditions, and facilitating a series of field management operations in the orchard. Schisandra cultivation mainly uses a single-wall trellis (plant spacing x row spacing of 2 m x 1 m or 2 m x 0.70 m), with a trellis height of 2 m and 3 to 5 horizontal wires used to fix the trellis poles. The main advantages of this trellis type are that it facilitates ventilation and light penetration on the trellis surface, improves fruit quality, and reduces pests and diseases.

Training

(1) Erecting trellis poles. Bamboo poles are often used as trellis poles, 2.0 to 2.2 m long, with a diameter of 1.5 to 2.0 cm at the thinner end. Two poles per plant are inserted on both sides of the plant. When plant spacing is 70 cm, the pole spacing is 35 cm; when plant spacing is 1 m, the pole spacing is 50 cm. The part inserted into the soil can be coated with asphalt to extend service life. The trellis poles are fixed to the wires with thin iron wire.

(2) Training. Schisandra often adopts a trunkless tree form with main vines, that is, about 2 fixed main vines are retained on each bamboo pole on both sides of the plant, and lateral vines, fruiting mother branches, fruiting branches, and vegetative branches grow on the main vines. Each plant needs 3 years to form its tree shape. During the training process, special attention must be paid to the selection and retention of main vines, choosing branches with strong growth vigor, full growth, and plump buds as main vines. The number of main vines must be strictly controlled; too many main vines will cause tree weakening and chaotic retention of branch groups.

Pruning of schisandra

(1) Winter pruning. Winter pruning, also called dormant period pruning, is carried out once per development cycle. The winter pruning period for schisandra is relatively long, and pruning can be carried out from 2 to 3 weeks after the plant enters dormancy until one month before the start of bleeding the following year. Pruning generally counts from the obvious bud eyes at the base of new shoots; leaving 1 to 4 buds is short-shoot pruning, among which leaving 1 to 2 buds or only the basal bud is super-short-shoot pruning; leaving 5 to 7 buds is medium-shoot pruning; leaving 8 or more buds is long-shoot pruning; and leaving 15 or more buds is super-long-shoot pruning. Schisandra is mainly pruned with medium and long shoots, and on the same tree, long, medium, and short shoot pruning should also be combined according to conditions. When pruning, the cut should be about 2 cm from the bud eye, and no branches should be left within the trellis surface 30 cm above the ground. Before the branches and vines have covered the trellis surface, only the immature part of the extension shoots of the main vines should be cut off; pruning of lateral vines should mainly use medium and long shoots, with spacing of 15 to 20 cm; leaf cluster shoots can be moderately thinned or not pruned. To promote basal bud germination and help cultivate reserve branches, short-shoot and super-short-shoot pruning can also be carried out. Medium and long shoots cut and retained the previous year should be promptly retracted; to appropriately increase the number of retained buds, fruiting small groups can be cut and retained, that is, two or more fruiting units are cut and retained at the same position on a lateral branch. Because the extension shoots of the previous year bear too much fruit, they should be renewed with vigorous branches.

(2) Summer trellis management. During the young stage of the plant, the selected and retained main vines should be promptly tied to the bamboo poles to promote upward growth. Lateral vines need to be tied to the wires according to their position, to the extent that they do not block each other's light. During the growing season, many sprouting shoots will emerge. The sprouting shoots climb onto the trellis surface, causing the trellis surface to become closed and affecting ventilation and light penetration. Therefore, sprouting shoots must be cleared to ensure normal ventilation and light penetration on the trellis surface and reduce nutrient competition.

Common problems in schisandra trellis management

1. Too many main vines retained. Because the annual branches and vines of schisandra are relatively slender and weak, some growers cannot bear to remove too many when selecting and retaining main vines. As a result, due to too many main vines, the selection and retention of fruiting mother branches becomes chaotic, which is not conducive to cultivation management and easily causes tree weakening.

2. Incomplete renewal during winter pruning. Because schisandra has a relatively large number of buds, branch groups weaken severely after fruiting. If timely retraction and renewal are not paid attention to, the tree will weaken further, affecting yield stability.

3. Failure to pay attention to tying fruiting mother branches in summer. Schisandra mainly fruits on medium and long shoots. Because fruiting mother branches carry a relatively large load after fruiting, they often droop, affecting ventilation and light penetration in the lower part, causing lower branches to grow insufficiently and affecting germination, flowering, and fruiting the following year. If this work is neglected for many years, the lower part of the plant will become bare, and yield will be noticeably affected.