ブドウにおける環状はく皮処理部位のテープによる被覆,枝齢,位置および師部組織の除去程度がはく皮部のゆ合と果実形質に及ぼす影響(栽培管理・作型)  [in Japanese] Effects of Taping, Branch Age, Position, and the Extent of Phloem Removal of Girdle on Healing of the Girdle and Fruit Characteristics in Grape(Crop Production & Cropping Type)  [in Japanese]

ブドウにおいて環状はく皮を効果的に行うことを目的に,はく皮処理部位の被覆,枝齢,位置および師部組織の除去程度がはく皮部のゆ合および果実形質に及ぼす影響について調査した.結果枝において師部組織の一部(師部最内層の薄皮状の組織)を残してはく皮したところ,着色および糖度は上昇しなかった.一方,師部組織を完全に除去すると被覆の有無にかかわらず,着色および糖度が上昇した.また,師部組織を完全に除去し,はく皮部を露出した区では,髄の一部がえ死した.同一樹内の異なる枝齢の部位にはく皮処理した結果,はく皮部の枝齢が古いほどはく皮部の上下からのカルスの肥大が速かった.しかし,はく皮部をビニルテープで被覆した場合は,このような枝齢によるカルスの肥大速度の差が明確ではなく,露出した木部から直接発生したカルスによる素早いゆ合が起こった.主幹へのはく皮における高さの違い(地上0.4,0.7,1.0および1.3m)は,はく皮の効果に影響を及ぼさなかった.このとき師部組織を完全に除去した後に,はく皮部を被覆しており,広範囲にブリッジが発生したが,いずれのはく皮位置でも着色および糖度が上昇した.以上のことから,師部組織を完全に除去し,はく皮部をテープで被覆することにより,環状はく皮の効果が発揮されるとともに,髄のえ死を防ぐことが明らかとなった.

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, 1.3m 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.