Abstract
Temperature treatments were conducted from early August to mid-September with 5-year-old bearing Kaki fruit trees (Cultivar. Fuyu) grown in clay pots.
1. When the trees were treated at night with temperature of 15°, 20°, 25° and 30°C and left in the field in the daytime from August 3, their fruits on September 21 showed no appreciable difference in the weight of a fruit among different temperatures except 30°C at which the fruit was lightest. Fruit color was already light yellowish green at 25° and 30°C. The chlorophyll content of the peel was lowest and the soluble solid content of the juice was highest at 25°C, followed by 30°, 20°, and 15°C in the order. However, the fruit quality on November 10 was most superior at 25°C and most inferior at 30°C.
2. When the trees were placed under constant temperature of 15°, 20°, 25°, and 30°C throughout day and night of August 6 to September 18, the weight of a fruit and its color at the end of treatments were best at 15°C, followed by 20°, 25°, and 30°C in the order. The fruit at 30°C was still green. However, the fruit quality on October 25 was most superior at 20°C and most inferior at 30°C. Brown specks resulted from the coagulation of soluble tannin substance developed more in flesh at 25° and 30°C than at 15° and 20°C.
