1992 Volume 36 Issue 1 Pages 14-20
Experiments were conducted to analyze the effect of strapping of secondary scaffold branches with covered, insulated wires (partial girdling) on fruit set, quality and flower bud formation in young persimmon trees, cvs. Saijo, Izu and Matsumotowase-Fuyu. The strapping treatments were performed by using covered, insulated wires 2.0 mm and 2.6 mm in diameter at 20 days after full bloom.
1. In the control treatment of cvs. Saijo and Izu, numerous summer shoots appeared and the fruit set percentages were low. After two strapping treatments in cvs. Saijo and Izu, the occurrence of summer shoots was suppressed and the fruit set percentages increased. In the control treatment of cv. Matsumotowase-Fuyu, the occurrence of summer shoots was low but the fruit set percentage was high. After the application of strapping treatments in cv. Matsumotowase-Fuyu, the fruit set percentages increased.
2. The fruit sizes in cvs. Saijo, Izu and Matsumotowase-Fuyu increased and the coloring degree was promoted by two strapping treatments. The fruit weight in cvs. Saijo, Izu and Matsumotowase-Fuyu increased by about 1.2 and 1.3 times, 1.3 and 1.3 times, 1.4 and 1.4 times, respectively after the application of two strapping treatments with covered, insulated wires 2.0 mm and 2.6 mm in diameter compared with the control treatment. The number of seeds in the three cultivars subjected to two strapping treatments was smaller than that in the control treatment.
3. The number of flower buds inside the winter bud on the shoot in cv. Matsumotowase-Fuyu increased after two strapping treatments. The number of flower buds in which the differentiation and development reached the sepal formation stage in cv. Matsumotowase-Fuyu increased by about 2.2 times and 2.6 times, respectively after two strapping treatments with covered, insulated wires 2.0 mm and 2.6 mm in diameter as compared with the control treatment. The number of flower buds in the part, of the spring cycle shoot with in the shoot which experienced a summer cycle in cv. Saijo, increased after two strapping treatments and the number of flower buds in which the differentiation and development reached the sepal formation stage increased by about 1.7 times and 1.8 times, respectively after two strapping treatments with wires as compared with the control treatment.
