Abstract
To study the influence of temperatures of the air condition upon the tillering of the rice plant, an experiment was made with six varieties including Japonica and Indica. The plants were cultured in growth cabinets, and the day length was controled as 12 hours, the light intensity being 22,000lux. The experimental plots used were 18.5°, 24.5° and 30.5°C. in the mean air temperature. The number of tillers decreased with rise of the air temperature in all of the varieties tasted, and this phenomenon was due to decrease of the secondary and tirtiary tillers, while the number of the primary tillers was unchanged. Difference of the growth habit of varieties gave different grades of the decrease of high position tillers with rise of the temperature, i.e. the decrease was conspicuous in varieties of the heavy panicle type.
