Thinning cuts improved fruit colour and hastened fruit and tree maturity in autumn for 'Yataka Fuji' on MAC.9

摘要

Effects of dormant pruning of 'Yataka Fuji' on MAC.9 rootstocks on tree growth, fruiting, fruit quality and on fruit and tree maturity in the season were investigated in Korea for integrated fruit production. Three pruning methods, the thinning cuts only, the heading cuts only and onetime heading cuts followed by thinning cuts only.to the shoots directly originating from ,the main stem, and to the leading shoots growing from the terminal buds of the previous growth on the branches developing on the main stem for heading cuts only were applied from 1991 to 1998. In spring of 1991 a single-whipped trees were planted and the trees Were trained more or less to be spindle bush types. Thinning cuts compared with heading cuts reduced extension shoot growth, increased yield, showed more highly coloured fruits. Thinning cuts hastened the fruit maturity and made it possible to pick larger number of total fruits and also larger number of highly coloured fruits earlier than heading cuts. Moreover, thinning cuts did not hinder the natural defoliation in late autumn while heading cuts kept some leaves at the shoot tips until early winter.