著者

滝内 基弘 橋本 康

出版者

The Society of Instrument and Control Engineers

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.13, no.5, pp.482-488, 1977-10-30 (Released:2009-03-27)

参考文献数

12

被引用文献数

2 1

---

The leaf temperature was measured by means of an infrared thermometer, which utilized PbTiO3 pyroelectric infrared detector, in connection with plant physiological information.The infrared thermometer was operated with a band pass filter of 9μm to 12μm, in which region the spectral reflectance of leaf is relatively low (less than 1% for tobacco leaf) and the averaged emissibity of leaf estimated by using Weber's method is nearly 1.0. The stability of the infrared thermometer proved to be better than 0.3K in terms of zero drift in a series of continuous operation and its best resolution of temperature was 0.1K. A high sensitive impedance meter was used simultaneously as for the measurement of water content in plants.The leaf temperature response of tobacco plant to light inputs and humidity inputs in various condition was measured in a controlled growth cabinet. The water content in stem, the transpiration and the gas concentration were measured simultaneously. As the result;(1) When the leaf was irradiated, oscillating changes in the leaf temperature in connection with changes in the water content of stem and in the transpiration were clearly observed.(2) The leaf temperature changed more rapidly at a higher air temperature.(3) The amplitude of leaf temperature change was greater at a lower air humidity.(4) A comparison between the results of temperature measurement obtained by thermocouple and those by infrared thermometer showed that the effect of the adhesive that was used for thermal contact of thermocouple on the leaf was not negligible.The results as a whole shows that the information obtained through the measurement of leaf temperature by means of infrared thermometer can present a key to make clear the phenomena in plant growth.