Effects of Ringing Time on Vegetative Growth, Fruit Quality, and Return Bloom of 'Fuji'/M.9 Apple Trees

In order to control tree vigor, 'Fuji'/M.9 apple trees in high density Orchard were ringed width 5 mm in 2004 in tree trunk in different phenological stages; terminal bud break, Full bloom and fruitlet (fruit size is about 15 mm). It was observed that ringing at bud break stage reduced the total shoot growth of trees to 64% of the uncut control, while ranging at full bloom stage to 73%, indicating that the early ringing, the more effective on controlling vegetative growth. When the trees were ringed at full bloom, return bloom was the highest, 85.7%, compared to the control of 33.6%. Ringing at bud break stage was remarkably increased return bloom to 56.0%, and resulted in low vegetative growth. Ringing at fruitlet stage only got a slightly higher return bloom compared to the control trees. Appropriate shoot growth reduction resulted from ringing ill tree trunk before Full bloom stage did not have certain negative effect oil fruit quality and improve tree flowering in the following year. With respect to increasing return bloom and yield efficiency, the optimum ringing time was Full bloom.