Effects of Two Different Training Methods on Dry Matter Partitioning and Translocation of ¹³C-Photosynthates in Young Trees of Japanese Pear ‘Gold Nijisseiki’

Abstract

Potted trees of 4-year-old ‘Gold Nijisseiki’ were used to compare two different training methods. The effects of 2-scaffolds and 5 or 6-scaffolds for young trees on the dry matter partitioning were studied. In addition, the trees were treated with ¹³C as a tracer in June and August to investigate how differences in training methods affected the translocation of photosynthates. Shoot growth was vigorous in the 2-scaffold trees. In contrast, multiple scaffold trees showed suppressed shoot growth, elongated older wood, and a large fruit number. Dry matter distribution ratios in different organs were compared. The ratio was high in shoots and shoot leaves of the 2-scaffold trees and in older wood and fruit of the multiple-scaffold trees. The distribution ratios of ¹³C in different organs were compared. The ratio was higher in fruit, older wood, trunks, and fine roots of multiple-scaffold trees than in those of the 2-scaffold trees; it was higher in shoots of 2-scaffold trees than in those of the multiple-scaffold trees. Consequently the multiple-scaffold training method was judged to suppress shoot growth, expand fast in the canopy of young trees, and promote an early increase in yield.