仁果类果树修剪的基本规律

The Basic Prunina Law of Pomaceous Trees

The growth of the canopy in fruit trees is always correlated with root system growth and depends upon water and nutrient supply and the ba- lance is kept. In young and vigorous pomaceous trees(apple, pear or haw- thorn), because the supply from the underground part surpassed the needs of aerial part, the whole tree became vigorous, especially under heavy prun- ing and too much cut-back, which stimulate shoot growth and exhaust most of the organic nutrients prepared for flower bud differenciation, so that the tree became low yield. In the senescent trees, the situation was just the opposited. To sum up the basic principle about pruning of fruit tree is that the correlation and equilibrium rules of the aerial and underground parts could be used in promoting young trees, maintaining the full bearing trees and renovating the senescent trees in order to reach the balance of all kinds of branches. It should be borne in mind that the light pruning is good for young and vigorous trees and the rejuvenating pruning is good for old trees.