Abstract
The effects of temperature on fruiting and development in Japanese apricot (Prunus mume Sieb, et Zucc.) cv. Nanko were investigated in sunlit glasshouses with constant temperatures at 10, 15, 20, and 25°C and under field conditions from 1st February. At the lowest temperature treatment, the temperature was kept at 10°C until the end of stage I of fruit development and then increased and kept at 15°C. 1. At higher temperatures, although anthesis was earlier, fruit set decreased because more imperfect flowers were formed. Fruit growth from full bloom followed a double sigmoid curve in each treatment. Because of the shorter period of stages I and II, the fruit maturation period was shorter at higher temperatures. The shorter period of stage II at temperatures higher than 15°C brought a lower cumulative daily-temperature during the whole fruit development period. 2. The weight and size of matured fruits became greatest at 15°C and smallest at 25°C. Some endocarps and seed growth were greatest at the lowest temperature. The total soluble solid in the flesh was higher at higher temperatures, but titratable acidity was not affected by temperature.
