Journal of the Japanese Society for Technology Education

Number 3
Volume 40


Development and Evaluation of a Computer Controlled Blue and Red LED Lighting System Used to Affect Plant Growth
Tomohiro YANAGI, Shinji Kondo, Kensyo OKAMOTO, Shinnichi TAKITA

There have been a noticeable absence of papers concerning the development of a system that uses a personal computer to artificially control the light conditions that affect plant growth. Because of this, we developed a lighting system that uses a blue and red light emitting diode(LED). This paper is an outline of the system we developed which includes the structural characteristics of the LED lighting system. &emdash;Further, we report on the light conditions under the LED light source, and an experiment that examines the practicality of this system. Using one personal computer made it possible to set and change the light conditions of eight different compartments with the LED light source. The light conditions ranged from darkness to about 100 mmol/m2/s intensity of blue/red light.

The experiment was carried out to examine what influence, if any, day length had on the floral initiation of Japanese morning glories. The results of the experiment demonstrated the practicality of the system. Therefore, this system can be considered an effective teaching tool for assisting junior high school students to understand the photoperiodism of plants in the horticulture field of technology and homemaking class.

Key words : personal computer, light emitting diode, LED, plant growing, Japanese morning glory, day-length