Abstract
The effects of taping, branch age, position, and the extent of phloem removal of the girdle on healing of the girdle and fruit characteristics in grapes were investigated. Retaining a part of the phloem tissue, which was the thin innermost-layer tissue of phloem, did not increase anthocyanin concentration of skins or diminish the increase in total soluble solids (TSS) of berries. In contrast, complete removal of phloem tissue increased the anthocyanin concentration and TSS, whether the girdle was taped or exposed. When the girdle was exposed, necrosis appeared in part of the pith. Callus developed faster in old branches than in young branches. However, when the girdles were covered with vinyl-tape, branch age did not affect the rate of callus development. Furthermore, girdled areas healed directly and rapidly eventhough phloem tissue was completely removed. Trunk girdling height of 0.4, 0.7, 1.0, 1.3 m above the ground did not affect the fruit characteristics. When the girdle was taped, girdled areas healed rapidly and widely after this treatment, but anthocyanin concentration and TSS increased. Based on these results, complete removal of phloem tissue and covering of the girdled areas with tape is necessary to increase anthocyanin concentration and TSS without causing necrosis in pith.
