果树的一生分三个发育阶段,即生长期、结果期和衰老期。生长期通常指苗木定植开始至开始结果的阶段,也叫营养生长期。这个阶段的主要特征是生长枝条,形成树冠,枝干、主根生长旺盛,水平根发展缓慢,枝条直立生长性强,细胞组织幼嫩,含水量高,有机物积累少,成花激素缺少,花芽不能形 Fruit tree’s life is divided into three developmental stages, namely, growth period, the results of the period and the aging period. Growth usually refers to the seedling planting start to the beginning of the stage, also known as vegetative growth period. The main feature of this stage is the growth of branches, the formation of crown, branch, root growth, the level of root development is slow, strong vertical growth branches, young tissue, high water content, organic matter accumulation, lack of flower hormones, flower buds can not shape