Abstract
Effects of light quality of artificial light source on the growth and morphogenesis of tomato and kidney bean were studied. White, red, yellow, green and blue lamps were used as artificial lights in the experiment. The light quantum irradiated for plants was set up at 2 levels of 400 and 200μmol·m-2·s-1and 300 and 150μmol·m-2·s-1 in photosynthetic photon flux density (PPFD) for tomato and kidney bean, respectively. Plants were grown hydroponically in the growth cabinet in which air temperature was maintained at 20/19°C (day/night) and day length was regulated to 12hr. Treatments were conducted for 14 and 30 days for tomato and kidney bean, respectively.
1) When plants were grown under high light intensity, leaf burning was occurred under green and blue lamps 5 to 6 days after treatment. The symptom, however, was not recognized under low light intensity. The internode of tomato plants under white lamp was longer than that under others. Dry weights of tomato and kidney bean plants under green and blue lamps were 15 to 30% lower as compared with other treatments. As the light under green and blue lamps contained higher rate of ultra-violet, it was suggested that uv seemed to cause leaf injury and to succulent the growth.
2) When tomato plants were grown under high and low light intensity, partioning of dry matter to the stem was higher under white than red or yellow. On the contrary, the its partioning to lateral shoot was 5 to 10 times higher under red or yellow than that under white. From these results, it was suggested that red/farred ratio affected the partioining of dry matter to each organ.
From the results obtained, it is concluded that light quality was recognized as growth reduced the plant growth by high light intensity of green or blue. However, that effects was not recognized clearly under low light intensity. Dry matter partioning, plant morphology, etc, were seemed to be affected with light quality regardless of light intensity.
