Cause of Top Rot Disease in Persimmon (Diospyros kaki Thunb.)

Persimmon fruit's top rot is a kind of physiological disease which damages fruit quality and product value at harvest. This study used 'Gongcheng' persimmon of Guangxi to test the influence of calcium and boron on top rot disorder. Results showed that disease incidence increased markedly in middle of October, supplement of calcium decreased the incidence significantly (7.7 and 12.2% lower than control/blank), while application of EGTA enhanced the incidence (32.4-39.7% higher than control/blank). Calcium supplement increased both calcium and boron content in fruits and leaves, boron supplement in part decreased the calcium in leaves, and application of EGTA totally reduced boron in fruits. The results showed certain relationship between persimmon's top rot incidence and calcium and boron in fruits and leaves. Effective way to improve their calcium and boron content might be helpful to prevent the disorder.