We investigated the light and temperature dependence of photosynthesis and its seasonal variations in the loquat cultivar ‘Mogi’ grown in a pot in an orchard. Leaf photosynthesis was light saturated in each season. The optimum temperature, at which net photosynthetic rate (Pn) was maximal, varied seasonally: 15°C in the fall, 5°C in winter, 20°C in spring, 25°C in the rainy season, and 30°C in summer. Maximum Pn value was 11-12 μmol CO2 m−2 s−1 in the fall and summer, 2 μmol CO2 m−2 s−1 in winter, and 6-10 μmol CO2 m−2 s−1 in spring and rainy season. Thus, our results suggested that loquat photosynthesis is temperature dependent. When loquat was moved to a phytotron in winter and kept at 13°C for 2 weeks, its maximum Pn increased considerably and almost reached the value of loquat that was continuously cultivated in the phytotron at 13°C during winter.
