Abstract
After storage for several weeks at 0°C, 'Saijo' persimmons (Diospyros kaki Thunb.) were treated with ethylene to obtain soft-ripened fruit. Fruit cracking occurred during soft ripening. There was a significant positive correlation (r=0.707*) between cold storage period and the ratio of the number of cracked persimmons to the total number of treated persimmons. Shallow cracks seemed to occur in linear groups on the cuticular layer but did not reach the pericarp. Most of them were seen along the ventral suture near the fruit apex. Ruptures occurred mostly on the lateral side of the fruit. The location of shallow cracks and ruptures on the fruit were considerably close, suggesting that the ruptures developed from the shallow cracks. The occurrence of ruptures was observed 2.0 to 4.5 days after the beginning of ethylene treatment. Ruptures elongated afterward and finally became 100-140mm long. Artificial deep injuries in the fruit significantly induced fruit cracking more effectively on the skin near the fruit apex than on the equatorial zone of the fruit. It was suggested that the development of shallow cracks during cold storage prior to ethylene treatment causes cracking.
