山楂叶片面积增大,以及随之而形成的叶幕,即全树总叶面积的年周期生长发育,受外界和内部条件的影响而产生变化。调查研究其变化规律,可为山楂生产技术管理提供依据,以充分利用叶片功能,达到壮树丰产的目的。 Hawthorn leaves area increases, and the resulting leaf curtain, that is, the total tree leaf area annual growth and development, affected by external and internal conditions and changes. Investigation of its variation can provide the basis for the technical management of hawthorn production, in order to make full use of the leaf function to achieve the purpose of strong growth of strong trees.