식물공장 시스템내 광환경 제어가 청경채 생장에 미치는 영향 = Effects of Light Environmental Control on Growth of Pak Choi (Brassica rapa) in a Plant Factory System

다국어 초록 (Multilingual Abstract)

Closed-type plant factory system using artificial light sources instead of sunlight is an ultimated method for plant production without any pesticides comparing to conventional greenhouse structure. Control of the light environment such as a light quality or intensity in the plant factory system using artificial lights is an essential technique for improving the growth and development of plant species. It has been reported that the light environment significantly influences on growth in many kinds of leafy plants cultured under the plant factory system. In this experiment, effects of light quality and intensity under hydroponic culture system were mentioned on growth of green and red Pak Choi (Braccica rapa var. chinensis) seedlings. The Pak Choi seedlings which developed 2∼3 unfolded leaves were cultured in Yamazaki nutrient solution controlled at 1.4 ds m-1 EC and 5.6 pH, respectively on the plant factory of horizontal type. The seedlings were exposed by monochromic or mixture light-emitting diodes (LEDs) of blue+white (BW treatment), red (R treatment), or blue+red+white (BRW treatment) with 50, 100, or 250 μmol m-2 s-1 light intensity for 5 weeks. Increment of fresh and dry weights in the green and red Pak Choi was significantly affected by blue+red+white or red light qualities. However pigmentation was inhibited by the monochromic red light in both of the green and red Pak Choi seedlings. In BRW treatment, fresh weights per seedling of green and red Pak Choi grown under 250 μmol m-2 s-1 light intensity were 5.5 and 8.4 times promoted, respectively compared with fluorescent light considered as a control. Pigmentation in the Pak Choi seedlings increased under BRW treatment with higher light intensity than in lower treatment. From the results, it is suggested that the mixture radiation with higher light intensity gave the maximum growth of Pak choi seedlings with higher quality comparing with monochromic light. Optimum light intensity for leafy plant growth inside the plant factory system using artificial light sources should be decided for commercial production with a lower electric cost.