There is an imbalance between different parts of the tree: generally, the lower branches are too thick and grow vigorously, while the upper branches and central trunk are thin and weak. Reasons for weakness: first, the lower branch rotates and pinches the neck; Second, the angle of the lower branch is small and too upright; Third, the door branches on the trunk are too large; Fourth, the fruit on the trunk is too much, too early or too few branches, resulting in weakness. The main solutions are as follows: first, thinning out too many main branches, cleaning up too many side branches, strictly controlling the number of main branches according to the requirements of the tree, and resolutely thinning out the main branches and side branches that affect the structure and growth of the tree; Second, by supporting, pulling and hanging the active branch opening angle, the results are promoted, and the potential is suppressed by the fruit, while the branches on the central trunk are shortened and promoted; Third, for branches that are too weak, under appropriate circumstances, competitive branches can be used to change their heads.
In dense planting gardens, the phenomenon of strong top and weak bottom is more serious. The main manifestations are that the lower branches are large in angle, weak, poor in growth potential, serious in baldness, and even the branchlets are dead; The upper branches stand upright, grow vigorously and shade seriously. The solution is to weaken the growth potential of the upper part by girdling and draining the upper part, increase the light and promote flowering and fruiting; Open the angle by pulling; Take measures such as slow release, less short cutting and more fruits to alleviate the upper branch potential and growth. For lower branches, the growth potential can be improved by cutting short, reducing the amount of fruit left and increasing the angle of branches.
Crown closure: In the orchard, there are three paths for light, namely, glass window, sunshade and sidelight. There are strong and weak trees. The big branches in front of the main branches are too big and too dense, and there are too many skirts, which will cause insufficient light in the crown, the crown is closed, and even the branches die. The solution is to open the glass window by thinning the branches; Draw light by retracting, raising the angle of branches, changing heads, etc. By thinning and introducing side light, the branches in the tree can see the light.
Excessive use of short cutting: in production, short cutting is generally to increase branches and strengthen growth potential. However, if the branches are short and each head is cut off, the number of branches will increase rapidly, forming a large number of "broom branches", which will affect the light in the crown, and the tree will grow branches and bear no fruit. The solution is to apply the shortcut method reasonably according to different situations. Young trees are short-cut, which are mostly used to cultivate the extension heads and branches of the central leadership trunk, main branches and side branches. Other branches are generally light and long, which promotes flowering and fruiting; Competing branches on the trunk or main branch can be thinned or shortened. In production, the effect of short cutting should be clear and short cutting should be carried out purposefully.
Improper branch pulling: the pear tree is upright and closed at a small angle, so it must be pulled and opened. However, in production, because young trees have no yield, fruit farmers often do not pay attention to management, resulting in upright branches; Although some fruit farmers also pluck branches, due to technical reasons, there are some problems that are not in place, such as plucking all branches regardless of quantity and variety, and letting them grow after plucking. The solution is: firstly, pruning and shaping are carried out in the young tree period, and all branches with enough length (generally 1 ~ 1.5m) are pulled to a suitable angle; Second, for the larger main branches, the method of pulling branches from the back of the arch or pressing branches with three saws is adopted to open the angle and expand the crown, so as to make full use of land, space and light energy; Third, pay attention to thinning straight branches and sprouting branches on the back after pulling branches.
Heavy pruning in winter, light pruning in summer: traditional pear cultivation often only prunes in winter, ignoring pruning in the growing period, resulting in a large amount of pruning in winter. The branches in the summer crown are not arranged in time, which affects the light and even aggravates the occurrence of pests and diseases, which is very unfavorable for the production of high-quality pollution-free fruits. Therefore, it is necessary to change the concept of pruning once in winter to pruning all year round, arrange branches at any time, and concentrate on supplying nutrients and reducing nutrient waste by methods such as wiping buds, removing sprouting, pulling branches, taking branches and carving buds.