1 Pruning technology \x0d\ 1. 1 Spring Pruning \x0d\ Spring Pruning of Toona sinensis belongs to styling pruning, which is usually carried out at the same time as the harvesting of Toona sinensis buds. From the second year after the cultivation of Toona sinensis, the top buds of 2-year-old trees will be removed, and 2 ~ 3 new buds will sprout in that year. If the height of the trunk is suitable, new buds can be retained and become 2 ~ 3 lateral branches after lignification; If the height of the trunk is too high, the new buds can be cored (not all buds can be picked) to promote the lower buds to sprout new buds. According to the required position, 2-3 sprouted new buds can be retained and become lateral branches after lignification. After the third year, new buds will grow at the top of the three lateral branches. When pruning, the terminal buds of three lateral branches will be removed. In that year, two or three new lateral buds will grow on each lateral branch, and new lateral branches will be formed after lignification. After this formation, each tree has 6 ~ 9 main branches. This kind of tree has high trunk, large branches, thick canopy, good ventilation and lighting, large harvest area and stable output. \x0d\ 1.2 Pruning in summer \x0d\ Because the yield and quality of Toona sinensis mainly depend on the number of terminal buds, it is necessary to prune Toona sinensis trees in summer to promote the formation of more branches. Pruning in summer is generally carried out on sunny days 15 in July and August, which is beneficial to wound healing, and it is not suitable for pruning on cloudy days. On the pruned Toona sinensis tree, the overgrown and overgrown branches are topped or truncated to promote the sprouting of lateral buds to form new branches, rejuvenate weaker parts and form more short lateral branches with full terminal buds. \x0d\ 1.3 winter pruning \x0d\ winter pruning is best carried out in early winter (or late autumn) and early spring dormancy period. Sparse dense branches, weak branches, pest branches, dead branches and perennial old branches with 1 tree age. Pruning knives and axes should be sharp. When pruning, they should stick to the trunk and cut it from bottom to top. The incision should be smooth and the wound should be small. Never move or strain the bark, which will affect the growth and development of trees. \x0d\ 1.4 rejuvenation \x0d\ After harvesting for 7 ~ 8 years, when the budding part moves out to the outer layer of the crown, the growth becomes weak, and the new buds are few and thin, indicating that the tree head is aging and should be replaced and updated. Head-changing is usually carried out when buds are picked in spring. Methods: Pruning and stubble-keeping began in the third year, that is, all branches born after the third year were pruned. Note that the stubble length of branches in the third year should be 20 ~ 30cm, so as to promote the development of new branches and keep the trees intact and robust. In the second year after the head change, new buds will grow on each stubble, but excessive pruning will cause the tree to grow poorly. If the stubble is not enough, new buds will often grow on the backbone branches in the second year, making the situation of the tree worse. Some rejuvenation only leaves the trunk, which will cause multiple branches to regenerate, and excessive pruning will also cause tree death.