Key points of winter pruning techniques for chestnut trees, easy for growers to understand at a glance

Question: How to prune chestnut trees in winter

Answer: Winter is the golden season for pruning chestnut trees. Winter pruning refers to pruning during the period from leaf fall to before bud break in spring. Winter pruning of chestnut trees is generally divided into pruning of young trees, pruning of mature trees, and pruning of old trees.

1. Pruning of young trees

The main purpose of pruning young trees is to form a high-quality, high-yield tree shape, also called training and pruning.

Commonly used tree shapes for chestnut trees include the natural open-center shape, the delayed open-center shape, and the trunk leader layered shape. The tree shape of chestnut trees is mainly determined by the chestnut variety, site conditions, and planting density. In the Yushan area, the main chestnut varieties are Maobanhong and Kuili, for which the natural open-center shape is suitable.

Training and pruning method for the natural open-center shape:

(1) In the year of planting, head the grafted seedling at 60-70 cm;

(2) In the second year after planting, select three vigorously growing branches to keep as main branches, requiring the angle between main branches to be about 120 degrees, the angle between the main branches and the central line of the trunk to be 30-45 degrees, and the distribution to be even;

(3) In the third year after planting, keep 2-3 sub-main branches on each main branch.

2. Pruning of mature branches

The key to pruning mature trees is to regulate the relationship between growth and fruiting, so that the tree vigor is moderate and the yield is high quality and high yield.

The pruning method for mature chestnut trees is mainly thinning, removing water sprouts, overlapping branches, crossing branches, densely growing branches, twin branches, thin and weak branches, and diseased and pest-damaged branches. According to the growth characteristics of chestnut trees, the requirements are: lightly prune strong trees, heavily prune weak trees; lightly prune strong branches, heavily prune weak branches. Selectively and moderately cut back vegetative branches and fruiting mother branches.

3. Pruning of old trees

For chestnut trees that have aged, renewal pruning should be carried out in a timely manner to rejuvenate tree vigor. Renewal pruning is mainly based on heading and retrenchment pruning. For mildly aged trees, cut off the upper part of large branches; for severely aged trees, retrench to the middle or lower part of large branches where strong branches grow. Cut off dead branches and diseased and pest-damaged branches.