低温要求量の少ないモモ品種 ‘KU-PP1’ および ‘KU-PP2’ の収穫適期の検討

概要

香川大学で近年育成された低温要求量が少ないモモ品種‘KU-PP1’および‘KU-PP2’について，流通のための適切な収穫時期を検討した．果実が十分なサイズに達してから，果皮色と果肉硬度の異なる4つの時期（ステージⅠ：淡緑色・硬い，ステージⅡ：淡黄色・硬い，ステージⅢ：着色・硬い，ステージⅣ：着色・軟化）に果実を収穫して，追熟させた．‘KU-PP1’では，ステージⅠに収穫した果実で追熟に6日，ステージⅡ，Ⅲで2日を要した．これらの追熟後の果実の食味はいずれも樹上完熟果実（ステージⅣ）とほぼ同等であった．‘KU-PP2’ではステージⅠ，Ⅱに収穫した果実で追熟に4日，ステージⅢで2日を要した．これらの追熟後の食味はステージⅠでは酸味がかなり強かったが，ステージⅡ，Ⅲでは樹上完熟果実とほぼ同等であった．これらのことから，‘KU-PP1’ではステージⅠ～Ⅲ，‘KU-PP2’ではステージⅡ～Ⅲでの収穫が流通に適していることが示された．流通に時間を要する場合は，‘KU-PP1’ではステージⅠ，‘KU-PP2’ではステージⅡの収穫がより適していると考えられた．
The appropriate time of harvesting for shipping fruit was determined in lower-chilling peach cultivars `KU-PP1'and `KU-PP2', bred at Kagawa University. After the fruit reached full size, they were harvested at the four developmental stages with different skin color and flesh firmness (stage I: pale green, hard; stage II: pale yellow, hard; stage III: pigmentation, hard; stage IV: pigmentation, soft) and then ripened. In `KU-PP1', fruit harvested at the stage I, II and III took 6, 2 and 2 days for ripening, respectively. The taste of their ripened fruit was almost same as that of the on-tree ripe fruit (stage IV). In `KU-PP2', fruit harvested at the stage I and II took 4 days for ripening, and that at the stage III did 2 days. The ripened fruit harvested at the stage I was too sour, but those at the stage II-III tasted as good as the on-tree ripe fruit (stage IV). These results suggested that harvesting at the stage I-III in `KU-PP1' and at the stage II-III in `KU-PP2' was proper for shipping fruit. For longer-term shipping, harvesting at the stage I in `KU-PP1' and at the stage II in `KU-PP2' seems to be more appropriate.