2003 Volume 72 Issue 5 Pages 372-377
The effects of summer-pruning (SP) and gibberellin (GA) paste treatments on fruit maturation, sugar accumulation pattern and incidences of watercore in Japanese pear (Pyrus pyrifolia Nakai) 'Akibae' were examined. Watercore increased with fruit maturation in all treatments although the SP treatment was effective in reducing and delaying the occurrence of watercore. Only 4 and 33% of the treated fruit were afflicted with the disorder .compared with 13 and 50% of the control at full maturity in 2000 and 2001, respectively. That SP alleviated GA-induced watercore shown by the decrease in watercore index during maturation period but not at full maturity. GA-pasted fruit had higher GAs content and matured earlier than did the 'untreated one, but no significant difference in endogenous GAs levels in fruits from the control and the SP plot. Fructose and sorbitol were the major sugars at the early stages of fruit maturation but sucrose was the predominant one at the mature stage. SP treatment had no effect on fruit development, maturity indices, including flesh firmness, and ground color, but somewhat delayed the accumulation of sucrose forward harvest compared with those of the untreated plots. These results indicated that SP treatment might reduce watercore disorder through by delaying sucrose accumulation in 'Akibae' fruit.