Relationships among Shoot Growth and Flower Bud Formation of Rabbiteye Blueberries

Relationships among the length of shoots, number of flower buds attached to shoots, and distribution of starch grains in the shoots of rabbiteye blueberries were investigated. The growth of shoots to 20 cm in length was weak. The shoot length showed an increasing tendency with an increasing number of flower buds attached to the shoot until 80 cm in length. Storage starch grains were observed in the cortex, xylem, and pith of the shoot, and the density in the pith was higher than in other organs. There was a strong positive correlation between the shoot length and percentage of the pith area in the cross-sectional area of the shoots. Hence, to obtain a stable yield, using shoots from 30 to 70 cm in length as bearing shoots under conditions of the Kanto region of Japan is recommended. The results of this study also suggest that summer pruned vigorous shoots could produce high-quality berries if the length of shoots is controlled.