(1) plastic
The purpose of plastic surgery is to cut off the competitive side branches that affect the growth of the top tip and ensure that the trunk is straight. As the trunk grows taller, it is necessary to trim the thicker competing branches in the lower and middle parts of the trunk until the trunk becomes straight and there are no branches below 8 meters. Plastic surgery should start after the first year of growth and reach the height of the tree10 ~14m, and the trunk has formed in 3 ~ 5 years.
(2) Pruning
Pruning is to cultivate industrial materials such as plywood and matches.
(1) Pruning age Poplars are generally not pruned within 3 years. In the autumn and spring after planting, it is only necessary to cut off the branches of pests and diseases or the competitive branches that affect the growth of the main branches, so that the young trees can try their best to develop the crown. However, when the trunk diameter of the lowest lateral branch of the crown reaches 8 ~ 10 cm, the lateral branch of this wheel should be pruned.
(2) Pruning time is usually carried out in the dormant period of poplar, but it can also be carried out in the growing season. However, pruning in severe winter or rainy season should be avoided, and the wound is not easy to heal, resulting in frostbite or infection. It is best to prune at the end of April and the beginning of May. At this time, the wound will heal quickly, without bleeding, and it is not easy to sprout.
③ The suitable pruning intensity should be determined according to site conditions, forest species characteristics, tree age, tree development and afforestation purpose. Too much or too little pruning will directly affect the growth and development of trees. The so-called proper pruning intensity should not only maintain proper crown and leaf area to ensure the vigorous growth of trees, but also gradually eliminate the lateral branches at the base of crown, reduce the knots of wood and promote the growth of trunk. The pruning intensity of poplar can be determined according to its height. Poplar trees of 4-8 years old should always keep the trunk height about 1/3 of the whole tree height and be pruned once a year. After 9 years, the trunk height should be kept at 1/2 of the whole tree height, so that the trunk can reach about 8 meters.
It is necessary to master pruning skills. The pruning tool should be sharp, and the incision should be smooth without leaving scars. When operating, you should stick to the trunk and cut (saw) it from the lower part of the branch, without tearing the bark and leaving stubble, so as not to form a dead knot, which will form a "hole board" when the wood is rotated.
(3) pruning sprouting strips
After pruning, sprouting strips will grow on the trunk below, so cut these sprouting strips as soon as possible. Pruning can be done in autumn, winter or spring when growth stops. Pruning should be close to the trunk without stubble. The tools used should be sharp, the wound should be smooth, and the bark should not be torn. It is often seen that poplar leaves side branches after pruning, which will grow into wood and become boils, which reduces the quality of wood and should be paid attention to.