Effects of harvest date on long-term storability of on-tree alcohol-treated 'Hiratanenashi' persimmons packed in plastic film

We investigated the effects of harvest date on the storability in cold storage (1degC and 5degC), of on-tree alcohol-treated 'Hiratanenashi' persimmons packed individually in plastic film. The persimmons, treated with ethanol on the tree to remove astringency on Oct. 3 (108 days after full bloom), were harvested on Nov. 2 (the color score near the fruit apex was about 5), Nov. 10 (the color score near the fruit apex was about 6 and the fruit surface was fully colored), and Nov.16 (the color score near the fruit apex was about 7). These persimmons were packed individually directly after harvesting in plastic film and were stored at 1degC and 5degC. The fruit samples from each harvesting date stored at 1degC had better storability than the fruit samples stored at 5degC. At either storage temperature, the fruit samples harvested on Nov. 2 had the highest storability. The storability of the fruit samples harvested on Nov. 2 judged by the rate of fruit softening was at least three months under cold storage at 1degC. Peel color index, flesh firmness, and soluble solid concentration of the fruit samples from each harvesting date at both storage temperatures changed very little during storage. The scores for eating quality of all fruit samples decreased slightly as the duration of cold storage was prolonged. Fluctuations in the score of the fruit samples stored at 5degC were larger than that of the fruit samples stored at 1degC. The eating quality of the fruit samples harvested on Nov. 2 was fairly good during the three month storage period.