고밀식 사과원에서의 간벌이 ‘후지’/M.9 사과나무의 영양생장, 생산량 및 과실품질에 미치는 영향

As apple trees mature, it is important to maintain good light distribution within the canopy to produce market able fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14–16 years after planting) to investigate the in fluence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle ‘Fuji’/M.9 apple trees planted with the tree space of 3.2 x 1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thin ning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thin ning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old ‘Fuji’/M.9 high-density apple orchards.