Evapotranspiration of sugarcane produced in Okinawa (Department of Agricultural Engeneering)

1本研究はサトウキビの10日平均日蒸発散量と気象要因との関係について検討したものである。2蒸発散量の資料としては1966年9月∿1971年2月に琉球大学農学部附属農場で測定した夏植えサトウキビの累積蒸発散量曲線から計算した値を用いた。気象要因としては月平均気温, 日最高気温の月平均値, 日最低気温の月平均値, 月間蒸発計蒸発量, 月間日照時間を採用した。3平均日蒸発散量とこれらの気象要因との関係は, 累積蒸発散量で直線で示される部分とLogistic曲線で示される部分に分けて検討した結果, 前者はすべて直線で示され, 後者は指数曲線で示されることがわかった。4月平均気温, 日最高気温の月平均値および日最低気温の月平均値から推定した値はほとんど同じ値になる。5平均日蒸発散量は月間蒸発計蒸発量により推定するよりは, 気温又は日照時間により推定した方がよいと考えられる。1. This study was done in order to investigate the relation between 10-day averages of daily evapotranspiration of sugarcane and climatic factors. 2. The daily evapotranspirations of sugarcane were calculated by cumulatic evapotranspiration curves which had been measured with three lysimeters from September, 1966 to February, 1971. The climatic factors used in this investigation are monthly temperature, monthly average of daily maximum temperature, monthly average of daily minimum temperature, monthly pan evaporation and mothly sunshine time. 3. The relations between 10-day averages of daily evapotranspiration and these climatic factors are linear for the linear part, and shown with exponential curve for the curvelinear part, on the cumulative evapotranspiration curves 4. The 10-day averages of daily evapotranspiration estimated by monthly average temperature, monthly average of daily maximum temperature and monthly average of daily minimum temperature have nearly the same values. 5. It seems better to estimate the 10-day averages of daily evapotranspiration by temperature or monthly sunshine time than by monthly pan evaporatio