PROBLEM TO BE SOLVED: To provide a moisture content observation apparatus, a moisture content observation method, and a cultivation apparatus, which can quantitatively and chronologically represent the transition of moisture content contained in a plant and contribute to the teaching of irrigation timing and an amount of irrigation water to the plant.SOLUTION: According to the present invention, a first projection light source irradiates the leaf of a plant with reference light of 905-nm near infrared light having the property that it can be hardly absorbed by moisture. A second projection light source irradiates the leaf of the plant with reference light of 1550-nm near infrared light having the property that it can be easily absorbed by moisture. A processing unit for threshold setting/moisture exponent detection calculates the moisture index of one leaf, which is the sum of reflection intensity ratios ΣLn(I905/I1550). A control unit displays on the UI screen of a monitor 50 a graph that represents the transition of the time series of the moisture content contained in the leaf of the plant from the start to the end of the measurement period. On the leaf of the plant, as viewed from the first projection light source and the second projection light source, a white background plate is placed, the place being disposed to cover the back of the leaf of the plant.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】植物に含まれる水分量の推移を定量的かつ時系列に提示し、植物への灌水のタイミングや灌水量の教示に資することができる水分量観察装置、水分量観察方法及び栽培装置を提供する。【解決手段】第１の投射光源は、水分に吸収され難い特性を有する９０５ｎｍの近赤外光を参照光として植物の葉に向けて照射する。第２の投射光源は、水分に吸収され易い特性を有する１５５０ｎｍの近赤外光を測定光として植物の葉に向けて照射する。閾値設定／水分指数検出処理部は、反射強度比の総和ΣＬｎ（Ｉ９０５／Ｉ１５５０）である葉１枚の水分指数を算出する。制御部は、測定期間の開始時から終了時までの植物の葉に含まれる水分量の時系列の推移を表すグラフをモニタ５０のＵＩ画面に表示する。植物の葉には、第１の投射光源及び第２の投射光源から見て、植物の葉の背面を覆う白色背景板が配置される。【選択図】図１
