关键词: 苹果, 更新修剪, 树体营养, 生长

Abstract: Compared with common pruning in Loess hilly and gully region of Northern Shaanxi，the effects of renewal pruning on mountain apple tree’s nutrition and growth at full productive age had been determined. The results showed that renewal pruning increased nitrogen，phosphorus，potassium，calcium contents in leaves and branches，and increased nitrogen，potassium and calcium contents in fruit，reduced nitrogen and calcium contents in roots，but had no significant effects on phosphorus content in fruit，phosphorus and potassium contents in roots. Renewal pruning significantly increased the proportion of long branch and medium branch，significantly reduced the proportion of short branch and leafage branch，and promoted branch robust development. Renewal pruning increased leaf area，chlorophyll content，fruit weight，fruit vitamin C and organic acid contents，but had no significant effects on fruit firmness，soluble solids，total sugar，and coloring area. Renewal pruning increased fruit yields and significantly improved orchard economic value.

Key words: apple, renewal pruning, nutrition, growth