茶樹の寒風害に関する研究(第1報) : 異なる環境条件が吸水量・気孔開度に及ぼす影響

The present study was undertaken to clarify thy mechanism of cold wind injury in tea plants. Water absorption and stomatal aperture were measured under differentlight (lighted or dark), air-temperature (2, 12, 16 or 22℃) and wind(blowing or notblowing) conditions in growth cabinets, from February to December. The materialsused in this experiment were 2 years rooted cuttings or mature shoots of the variety "Yabukita".
The results obtained were as follows ;
1. The rate of water absorption in light conditions was higher than in dark conditions. The increase in air-temperature resulted in the increase of the rate of water absorption. Under wind blowing conditions, the rate of water absorption was increased in June to October.
2. Under 2℃ of air-temperature in December to March, the rate of water absorption was not increased in light and wind blowing conditions.
3. Stomatal aperture were larger in light conditions than in dark conditions. Under wind blowing conditions, stomata were gradually closed, but in the winter season, stomata were not sharply responsed to wind blowing treatment.
4. From the results mentioned above, it is suggested that in the winter season, the rate of water absorption was not well balanced to the rate of transpiration.