“小老树”桔园,是指已经达到年龄而不投产的桔树,远观之与幼树相同,矮而小,5—6年生树,桔树复盖率还不到10％;近观之桔树老化而衰弱。主枝瘦弱,小枝纤细,春梢短而丛生,夏秋梢少;叶片薄而小,叶颜色淡无光泽。骨干根瘦弱,须根少,根群不发达,分布浅而狭窄,死根多,新根少,因而吸收能力弱。枝叶稀疏,光合面积小,同化产物不能充分供应根系生长;地下根系局限在土壤表层或仅在栽植穴内盘根错节,吸收面小,不能为枝叶生长提供充足 “Small old tree” Orange garden, refers to have reached the age without the production of orange trees, as far as the same with young trees, short and small, 5-6 year old tree, orange tree coverage rate of less than 10%; nearly View of orange trees aging and weak. The main branches of thin, branchlets slender, spring shoots short and clusters, summer and autumn shoots less; thin and small leaves, leaf color dull. The backbone of the root thin, less fibrous roots, root groups underdeveloped, shallow and narrow distribution, dead roots and more, less new roots, and thus weak absorption capacity. Sparse foliage, photosynthetic area, assimilation products can not fully supply the root growth; underground roots confined to the surface of the soil or only in the planting hole in the wrong section, the absorption surface is small, can not provide enough for the growth of branches and leaves