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The unit concerning the light in the plant production

Caution: This page contains JavaScript source code.

Produced By Hoshi, Takehiko, Ph.D. (Tokai University)
Light and Plant Growth, Youkendo Co., Ed. By Dr. Inada, Katsuyoshi
Physical Terms Concerning Light, SHITA Report 8, Japanese Society of Hight Technology in Agriculture, By Prof. Hayashi, Makio

As an environmental condition which influences the growth of the plant, the light is very important. In the field of plant physiology and cultivation science, the light condition given until now to the plant using the unit of the illuminance was quantified. It is because it seemed to use the cheap illuminometer by using abundantly in the human-engineering application, in the ancient. However, this is not an adequate method.

And, it is not very much the accuracy in the field of the environmental engineering, because that it is done, because the case in which short wave radiation flux density ( the or, PARFD: Photosynthetically Active Radiation Flux Density) is used was abounding, is also unit of energy on this. It is considered that it recently and be more adequate to use photosynthesis photon flux density ( PPF or PPFD ) for expressing the light environment concerning the photosynthesis. However, it is convenient in order to utilize the value tested in a past, when illuminance, etc. can convert it into PPF. In this page, it would be able to execute unit conversion on the light environment in every light source where there is using JavaScript in reference literature. It is used and is given free.


  1. Lighting Environment and Units
  2. Conversion of Light Environment Units
  3. Unit Conversion Table

Copyright (C) 1999 Takehiko Hoshi, Tokai University, Shizuoka JAPAN