臺東區晚崙西亞橙冬春季蒸發散量測定之研究（初報）

Preliminary Studies on the Measurement of Evapotranspiration for Valencia Orange in Winter and Spring in Taitung Area

在冬春晚崙西亞橙之蒸發散量，經初步測定果，於果實黃熟期（亦即春芽萌發開花期）為最多。在此時間應特別注意灌溉，否則將影響生育和果實的產量及品質。其最低灌水量五年生者為2 mm，十年生者為2.4 mm，十九年生者為3 mm。至於果實微黃期、成熟期、生理落葉期和幼果期（夏芽發伸長期），因蒸發散量較少，其灌水量可以減為五年生1~1.4 mm，十年生14 mm，十九年生1.5~1.7 mm。

This experiment was conducted to study the evapotranspiration of the mature Valencia orange trees in the winter and spring in l971-73. In this experiment a specially auto-irrigation apparatus, was designed and the soil moisture content was controlled at 60-70% of the field capacity. The results indicated that the amount of evapotranspiration increased with the age of orange trees. When the, fruits reached the yellow maturing, stage (January to February), the evapotranspiration was in maximum and decreased before or, after this stage. Usually, increasing temperature. sunlight and relative humidity would, increase the evapotranspiration. It is suggested the amount of irrigation for Valencia orchard should be more in January and February.