关键词: 苹果, 栽植密度, 矮化中间砧, 树体生长, 产量, 品质

Abstract: The‘Fuji’apple with SH6 dwarf interstock planted in spring 2011 was used to investigate the effect of 7 different tree planting densities（1 m × 3 m，1.5 m × 3 m，2 m × 3 m，0.75 m × 4 m，1 m × 4 m，1.25 m × 4 m and 1.5 m × 4 m）on growth，distribution of light in the canopy，yield and quality in Beijing from 2012 to 2018. By the 7th year of planting，the total number of branches in 1 m × 3 m and 0.75 m × 4 m planting densities exceeded 1.4 million · hm-2，and by the 8th year of planting，the total number of branches in each planting density exceeded 1.4 million · hm-2. In the first four years，with the growth of age，the proportion of long branch was decreased，the increasing proportion of short branches of all planting densities was increased. From the fifth year，the number and proportion of branches of different lengths began to be stable. According to the branch composition of trees with stable yield for 3 years，the proportion of short branches with 4 m row spacing was significantly higher than that with 3 m row spacing，while the proportion of long branches was slightly lower. Under different planting densities，there were great differences in the distribution of canopy light. The average relative light intensity of canopy was 1.5 m × 4 m（63.87%），1.25 m × 4 m（61.44%），2 m × 3 m（61.27%），1 m × 4 m（59.19%），0.75 m × 4 m（55.79%），1.5 m × 3 m（53.67%）and 1 m × 3 m（49.37%）from high to low. Under the same plant number，the proportion of low light efficiency（relative light intensity less than 40%）in 4 m row spacing treatment was significantly less than that in 3 m row spacing treatment. Compared with the cumulative yield in the previous five years，row spacing of 4 m was significantly better than row spacing of 3 m，and the cumulative fruit yield was the highest under three planting densities of 0.75 m × 4 m，1 m × 4 m and 1.25 m × 4 m. According to the results of three years’ stable yield，the order of big fruit rate（the proportion of fruit weight > 200 g to total yield）from high to low was 1.25 m × 4 m > 1.5 m × 4 m > 1 m × 4 m > 2 m × 3 m > 0.75 m × 4 m > 1.5 m × 3 m > 1 m × 3 m，and the big fruit rate of 4 m row spacing was obviously higher than that of 3 m row spacing. Comparing the fruit quality of different planting densities，there were no significant differences in soluble solids content，solid-acid ratio，fruit shape index and fruit firmness among different planting densities. We recommend using row spacing of 4 m and plant spacing of 1–1.25 m in production.

Key words: apple, tree planting density, dwarf interstock, tree growth, fruit yield；quality