抄録
Temperature of leaf-sheath or stem of rice plant grown in pots with or without flood-water, being soaked in water bath of different temperatures, was self-registered using thermocouples. The temperature of the base of leaf-sheath and stem was higher than the surrounding air when the soil-and water temperature was higher than that of the air, being especially high without flood-water. When the pots with flood-water were soaked in bath of lower temperature, the base part of the plant was cooler than the surrounding air and the other plant parts, due-probably to evaporation of water drawn up by capillary action on the surface of leaf-sheath or-stem. This cooling phenomenon was not seen in the pots without flood-water, and was more conspicuous on the outer surface of the base than the interior part, and was promoted by wind. The fact that the growth of rice plant at a vegetative or earlier reproductive stage with the shoot apices close to the soil or water surface, is strongly regulated by the soil-and water-temperature, while that at a later growth stage with the apices at higher levels it is largely affected by air temperature, may be understood in relation to the temperature conditions around the shoot apices as was mentioned above.
