幼树和初结果的果树,主枝背上枝多而旺,背下枝弱,是生产上经常出现的问题,背上旺长的后果是恶化光照,使主枝上下左右的枝量平衡受到破坏。出现主枝背上旺长的原因,可归纳为以下几方面。1 主枝背后和两侧留枝过少。2 主枝角度开张过晚、过大、过急。 Saplings and early fruiting trees, the main branch of the back of the branches and more prosperous, the back of the branch is weak, is the production of the frequent problems, the consequences of the back of the growth is to deteriorate the light, so that the main branch up and down about the balance of branches destroyed. The main reasons for the emergence of the main branch back, can be summarized as the following aspects. 1 behind the main branches and on both sides too few branches. 2 main branch angle opened too late, too big, too anxious.