Trellis Management Techniques for Home Cultivation of Schisandra

I. Trellis Types for Schisandra

Schisandra is a perennial twining vine with slender, soft stems that need to twine clockwise around other supports to grow upward. Therefore, under home cultivation conditions, trellis poles need to be set up so that Schisandra maintains a certain tree form, and the 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 garden. Schisandra cultivation mainly uses a single-wall trellis, (plant spacing 2 m x 1 m or 2 m x 0.70 m), with a trellis height of 2 m; 3-5 horizontal iron wires are stretched to secure the trellis poles. The main advantage of this trellis type is that it facilitates ventilation and light penetration on the trellis surface, improves fruit quality, and reduces pests and diseases.

II. Training

(1) Erecting Trellis Poles Bamboo poles are often used as trellis poles, 2.0-2.2 m long, with a thinner-end diameter of 1.5-2.0 cm, two per plant, inserted on either side of the plant respectively. When plant spacing is 70 cm, the trellis pole spacing is 35 cm; when plant spacing is 1 m, the trellis pole spacing is 50 cm. The part inserted into the soil can be dipped in asphalt to extend the service life. The trellis poles are fixed to the trellis wires with thin iron wire.

(2) Training The tree form commonly used for Schisandra is a two-group main vine trunkless form training method, that is, about 2 fixed main vines are retained on each bamboo pole on either side of the plant, and side vines, fruiting mother branches, fruiting branches and vegetative branches grow on the main vines. Each tree needs 3 years to form its tree shape. During the training process, special attention should be paid to the selection and retention of main vines; branches with strong growth vigor, full growth and plump buds should be selected as main vines. The number of main vines must be strictly controlled; too many main vines will cause tree decline and chaotic retention of branch groups.

III. Pruning of Schisandra

(1) Winter Pruning Winter pruning is also called dormant period pruning, carried out once per development cycle. The winter pruning period for Schisandra is relatively long; pruning can be done from 2-3 weeks after the plant enters dormancy until one month before the start of bleeding the following year. In Northeast China, Schisandra pruning is best completed in mid-to-late March. Pruning generally starts from the obvious bud eye at the base of the new shoot; leaving 1-4 buds is short-shoot pruning, of which 1-2 buds or only the basal bud is ultra-short-shoot pruning; leaving 5-7 buds is medium-shoot pruning, 8 buds or more is long-shoot pruning, and 15 buds or more is ultra-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 30 cm of the ground on the trellis surface. Before the branches and vines have

covered the trellis surface, only the immature parts of the main vine extension branches are cut off; side vines are mainly pruned as medium and long branches, with a spacing of 15-20 cm, and leaf cluster branches can be moderately thinned or not pruned. In order to promote basal bud germination and facilitate the cultivation of reserve branches, short-shoot and ultra-short-shoot pruning can also be carried out. Medium and long branches left from the previous year's pruning should be promptly retracted; to appropriately increase the number of retained buds, fruiting units can be left, that is, two or more fruiting units are left at the same position on a side branch. The previous year's extension branches, due to excessive fruiting, should be renewed with vigorous branches.

(2) Summer Trellis Surface 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. Side vines need to be tied to the iron wires according to their position, to the extent that they do not block each other's light. During the growing season, many adventitious shoots will sprout, and the adventitious shoots climbing on the trellis surface cause the trellis surface to become closed and affect ventilation and light penetration. Therefore, adventitious shoots must be cleared to ensure normal ventilation and light penetration on the trellis surface and reduce nutrient competition.

IV. Common Problems in Trellis Surface Management of Home-Cultivated Schisandra

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 decline.

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

3. Failure to pay attention to tying fruiting mother branches in summer Schisandra mainly fruits on medium and long branches. Because the mother branches have a large load after fruiting, they often droop, affecting ventilation and light penetration in the lower part, making the lower branches grow poorly, 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.