Young tree shaping is to lay a good foundation for cultivating early fruiting, high yield, stable yield and long life. After planting, all young trees with upright branches should be pulled out, that is, when the new buds sprout in spring after planting, the branches with small branching angles should be pulled out to more than 45 degrees with a string, and then loosened when the new buds mature, so that the branches can be restored to 45 degrees. In most citrus producing areas in hot areas, neat and strong summer and autumn shoots are cultivated by wiping buds and controlling shoots. The specific method is to wipe the buds every 3 ~ 4d after the terminal buds of the scattered branches germinate, and stick to 15 ~ 20d. When most branches of the whole tree germinate 3 ~ 4 new buds, then release the new buds (let them germinate freely). Pruning young trees is mainly to control summer shoots and cut off long branches and weak winter shoots. A large number of summer shoots often cause fruit drop, and fruit drop is controlled by wiping buds. Summer shoots can't be released until the cross diameter of fruits is about 3cm (different varieties) and the seeds meet. In addition, in summer or winter, drooping branches and long branches and weak winter buds should be cut off.

(2) Pruning of adult fruit trees

The light in the hot area is strong, and most varieties have certain fruit-setting ability in the crown. Pruning generally adopts the method of "short cutting, internal shrinkage, topping, external thinning and internal finishing". The main objects of shortening are fruiting branches (several fruits are concentrated on one branch), falling flowers and fruiting branches, and various declining branches in the periphery of the middle and upper parts of the crown. 5 ~ 10 cm branch piles should be cut and trimmed back to spit out new buds. The thickness of cuttings depends on the age of trees. In summer, high temperature and high humidity make the hair tip exert force, and the thickness of the cut should be 0.5 ~ 0.8 cm. The ability to germinate new shoots at low temperature in winter and spring is not as good as that in summer, and the cutting diameter is generally 0.8 ~ 1.2 cm. Topping and weeding is to compress and prune the aging or declining branches at the top of the crown after high yield, and prune some overgrown branches at the top of the crown of a mature tree from the base without leaving a pile of branches. External thinning and internal consolidation are the proper thinning when the branches outside the crown are too dense and the trees cross to shade in winter, so that the sun can penetrate into the inner room; However, we should try our best to keep the branches inside the crown, and only trim some branches that are excessively shaded, delicate and have thin leaves, so as to enhance the fruiting ability inside and below the crown. During pruning, Guangdong and other provinces promote pruning twice a year, with summer pruning 15 ~ 20 days before the release of autumn shoots, with the aim of promoting vigorous fruiting branches, and winter pruning after fruit picking.

(3) Renewal and pruning of aged trees

After the citrus entered the senescence stage from the full fruit stage, the vegetative growth was extremely weak, the senescence branches increased and the yield decreased. Renewal pruning is to cut off the aging part of the tree and promote it to form a new crown, thus improving the productivity of the old tree. Generally, according to the degree of recession, different methods such as rotation renewal, dominant renewal and main branch renewal are adopted. Crown regeneration can be combined with root regeneration, and sufficient decomposed organic fertilizer can be applied to promote its growth.