LIGHT CONTROL SYSTEM (LCS) DEVELOPMENT AND ITS APPLICATION FOR PLANT PRODUCTION IN A PLANT FACTORY SYSTEM

In this paper, the utilization and light characteristics of light control system (LCS) using light-emitting diode (LED) which was developed for plant production inside plant factory system were experimentally investigated. Characteristics of the monochromatic red (R), blue (B), green (G), and white (W) lights and mixed lights of blue, red, or green LED were studied by spectrometer-MMS1 and illuminometer. In our LCS, power consumption of each LED was 1W, and the each LED has five wave¬length bands. Light intensity, and lighting type of continuity or intermittence can be controlled at 10-100% required for plant growth and development can be also achieved by the LCS. Utilization of the LCS in a plant factory system was suggested by the experimental results of promoted growth and metabolism in several plant species. There was no significant difference in fresh weight of Radish sprouts cultured under BR mixture or the conventional fluorescent lighting condition. However, the mixture-light quality provided by the LCS gave the higher phenol contents in the plants.