ニホンナシ'新高'の果頂部切除処理による果形の改善(栽培管理・作型)  [in Japanese] Improvement of the Fruit Shape of Japanese Pear 'Niitaka' by Excision of the Calyx Lobe in Young Fruits(Crop Production & Cropping Type)  [in Japanese]

ニホンナシ'新高'では,果頂部の突出した果実が発生することが問題となっている.そこで,幼果期に突出した果頂部を切除処理し,果形と果実品質に及ぼす影響を検討した.果頂部の突出した幼果に対して,満開後30日前後に突出部を先端から2〜3mmの位置で切除処理すると収穫時の果形が改善され,切除痕は,満開後30日前後の切除処理では目立たず,それより処理時期が遅くなるものほど甚大となった.また,切除処理による障害果発生率果実品質低下等の影響は認められず,果頂部の裂皮や裂果の発生は減少した.切除処理時の天候条件は切除部の腐敗や収穫時の果実品質に悪影響を及ぼさなかった.本処理は,果頂部突出幼果の多発年において,高品質果実の安定生産を図る上で有効な手段と考えられる.

During the harvest period, Japanese pear 'Niitaka' with a calyx lobe has sometimes been observed in production areas in Okayama prefecture. In 2001 and 2003, the effects of excising the calyx lobe in young fruits on the shape of 'Niitaka' were examined. When excised up to a depth of 2-3 mm within 30 days after full bloom, most of the traces of excision had disappeared, and the shape and quality of the matured fruits were observed to be almost ideal. Furthermore, the incidence of fruit cracking decreased. Weather conditions at excision did not influence the quality of the matured fruits undergoing excision of the calyx lobe. These results show that this treatment is effective in improving the shape of young fruits possessing a calyx lobe; hence, it is suitable for stable production of the pear.