Effects of Soil Moisture on Photosynthesis , Transpiration and Stomatal Resistance in sotghums II.Ondiurnal changes

토양수분이 수수류의 광합성 , 증산량 및 기공저항에 미치는 영향 II. 광합성과 증산량의 일중변화

  • Published : 1986.01.30


To determine the effects of soil moisture on diurnal changes of photosynthesis, transpiration and stomatal resistance, sorghum and soghum-sudangrass hybrid were grown at large concrete pots maintained at 100, 80, 60 and 40% of field moisture capacity. Photosynthesis were measured from a.m. 6 to p.m. 6 on a fine day. 1. Photosynthesis and transpiration reacted similarly to water stress and environmental factors, and they reached at their maximum points from noon to 2 p.m. and decreased sharply after 4 p.m. 2. Photosynthesis and transpiration of sorghum were higher at 60% field moisture capacity than those of the other field moisture capacities. In sorghum-sudangrass hybrid, photosynthesis was in the order of 60>80>40>100% and transpiration was in the order of 60>80>100>40%. 3. Stomatal resistance did not show clear diurnal change and was the lowest at 60% among four field moisture capacities.