2. Pruning methods and techniques of protected fruit trees: Because protected fruit trees in greenhouses and greenhouses are more vigorous than those cultivated in the open field, when hedgerows are used for pruning, the crown is often stronger on the top and weaker on the bottom, and the height and potential of trees are difficult to control. In addition, the quality of branches and buds at the lower part of the crown often decreases due to insufficient light, and the resulting parts move outward. Practice has proved that canopy pruning with flat shed can effectively overcome the above shortcomings, thus stabilizing tree potential, ensuring high quality and high yield of fruit trees, and greatly reducing pruning times in summer. The tree shape of flat shed mostly adopts the pruning method of shed facilities mentioned above, and its pruning technology is not repeated here. Due to the limited space of protective facilities such as greenhouses, it is necessary to strictly control the tree potential and height to avoid the high temperature environment above the facilities from burning the leaves. Therefore, the key point of pruning management in growth period is to prevent the vigorous growth of new shoots. In terms of measures, in addition to using chemical control, artificial branch pulling, branch tying and coring should be carried out in time. At the same time, we should also pay attention to the influence of dense branches on the ventilation and light transmission of the crown. If necessary, we can properly thin branches, and according to experience, it is best to wipe buds at an early stage to save nutrients and improve the quality of trees. When the crown volume can no longer adapt to the original planting density with the growth of tree age, the ventilation and light transmission problems should be solved by draining temporary plants and retracting permanent plants, so as to alleviate the phenomenon of premature defoliation and dead branches and buds at the lower part of plants, and effectively alleviate and control the problems of strong upper part and weak lower part, outward movement of fruit parts and infection of pests and diseases in hedge pruning fruit trees.
3. Pruning technology of three main edges of Japanese pear trees with flat shed facilities: the three main edges are high-coverage windproof safe production trees in Japan. The main structural feature is that three main branches are cultivated from young trees, and uniaxial extension side branches with direct results are cultivated on the main branches. Then, with the expansion of the crown and the increase of the branch density, the number of lateral branches gradually decreased, and a uniaxial extension of the branch group was cultivated on the permanent large lateral branches in the middle and lower parts. The number of side branches can be up to 2 1 at most, and finally reduced to 15. They are symmetrically arranged on the main branches, with a spacing of 60 cm. They look like fishbone ribs, so they are called three main ribs. Bare legs are easy to occur in the middle and lower parts of main branches and side branches, and bud grafting technology is mainly used to promote branch culture and fruiting branches. The gap between the cavities of the three main branches can be made up by the long branches at the base of the first side branch by reverse combination culture. The diameter of the formed crown can reach 8 ~ 9 meters. This kind of tree was originally designed to prevent fruit drop caused by typhoon, but it was later proved that it can weaken the top advantage and improve the budding and branching ability of middle and lower branches, thus effectively controlling the strong upper part and weak lower part and the outward migration of fruit parts, achieving safety, high quality and high yield, and facilitating management (Figure 103).