PROBLEM TO BE SOLVED: To provide a growth state evaluating device suppressing the occurrence of measurement errors.SOLUTION: This growth state evaluating device includes irradiating an object to be measured 40 with a plurality of light beams having a different emission wavelength, and detecting the reflected light followed by evaluating a plant growth state. The device includes an LED 28a whose emission wavelength (λ1) is present in a wavelength area of red edge of a spectral reflectance ratio of the object to be measured 40, and an LED 28b whose emission wavelength (λ2) is present in a flat wavelength area having a wavelength longer than the red edge wavelength area, and a light detector 28c detecting each irradiation light of the LED 28a and 28b. The propagation light path of the irradiation light of the LED 28a, and the propagation light path of the LED 28b coincide with each other.COPYRIGHT: (C)2013,JPO&INPIT【課題】測定誤差の発生を抑制することができる生育状態評価装置を提供する。【解決手段】測定対象物40に対し発光波長の異なる複数の光を照射し、その反射光を検出して植物の生育状態を評価する生育状態評価装置が開示されている。当該装置は、発光波長(λ1)が測定対象物40の分光反射率のレッドエッジの波長領域に存在するLED28aと、発光波長(λ2)が前記レッドエッジの波長領域よりも長波長のフラットな波長領域に存在するLED28bと、LED28a,28bの各照射光を検出する光検出器28cとを備え、LED28aの照射光の伝播光路とLED28bの伝播光路とが一致する。【選択図】図3
