Abstract
We investigated inhibitory effects of the formation of axillary flower buds by pinching and defoliation of current shoots on four different cultivars of Japanese pear (Pyrus pyrifolia (Burm. f.) Nakai), to save labor for disbudding on the main one-year shoot of the scaffold branch. In ‘Housui’, the average rate of axillary flower bud formation was normally 86-95% in 2002-2004, but by pinching one-third off the shoot 50-65 days after full bloom, the rate in treatment was reduced to 40-54%. Further, the secondary growth of shoots was promoted by earlier pinching treatment, and the flower buds formation was more effectively inhibited by secondary growth. In ‘Shinko’, ‘Kousui’ and ‘Shurei’, the earlier pinching treatment caused the same results as ‘Housui’, which inhibited the formation of axillary flower buds. The bud formation was especially inhibited not only in the part showing secondary growth but also in that showing first growth. The defoliation treatment 50-65 days after full bloom inhibited the formation of axillary flower buds in ‘Shinko’ only. Thus, these findings suggest that the earlier pinching and defoliation treatment of current shoots can be a technique to control flower number as the working period does not compete with the disbudding period.
