抄録
Information on water uptake by plants is useful for management in greenhouse cultivation (e.g. irrigation control). In this paper, we continuously measured water uptake by long-term tomatoes grown in a re-circulating hydroponic system in a glasshouse through two entire cultivation periods (Each cultivation period was 9-10 months long, from mid-winter to mid-summer). Amount of water uptake by plants was measured by monitoring the amount of water supplied to the hydroponic system. Over 95% of total water uptake by the plants throughout cultivation period was passed through the plants as transpiration. Daily amount of water uptake increased with the increase of leaf area until LAI reached 1.5, then was not significantly affected by LAI. Day-by-day change of daily water uptake amount was primarily associated with change of daily-accumulated solar radiation. Daily water uptake amount by long-term tomatoes was well estimated by a multiple regression equation including daily-averaged air temperature and water vapor pressure deficit in glasshouse in addition to daily-accumulated solar radiation as independent variables.
