• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.16-23
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• 2016

This study was carried out to investigate the effects of artificial light sources on growth and yield of hydroponically grown Peucedanum japonicum in plant factory. Treatments were composed with; florescent lamp(FL) as control, and LED lights; R:B(2:1, RB), R:B:W(2:1:3, RBW), and R:B:G:W(2:1:0.5:3, RBGW). Plant height of RBGW and FL treatments were superior to RB and RBW. Leaf weight of RBW and RB were superior to FL and RBGW. There were no significant difference of leaf length and thickness among the treatments. Lightness of leaves was same tendency with plant height. Total phenolic compound content was the high in order of RB as $105.77mg{\cdot}100g^{-1}$ GE, RBW as $92.52mg{\cdot}100g^{-1}$ GE, FL as $89.08mg{\cdot}100g^{-1}$ GE, and RBGW $82.00mg{\cdot}100g^{-1}$ GE. Total flavonoids were not detected in all treatments. Vitamin C content was the highest in RB and the lowest in FL. Total dietary fiber were the highest in FL and the lowest in RBGW. There was no significant difference cystein and methionine contents among the treatments. Concludely, yield, total phenolic compounds, and vitamin C content was high in RBW and RB. We reached conclusion that RBW is best artificial light source considering yield, functionality and eye fatigability when work. We recommend to further study LED pulse and duty rates for increasing functionality.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.143-149
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• 2019

This study was conducted to investigate the graft-taking and growth of grafted cucumber seedlings as affected by light quality and blink cycle of LED modules. Four light quality treatments, namely blue, red, blue+red, white LED and four blink cycle levels of 5s/5s, 7s/3s, 9s/1s and control were provided to investigate the effect of lighting quality and blink cycle on the graft-taking and growth of grafted cucumber seedlings. Photoperiod for the control was 12/12 h. Photosynthetic photon flux, air temperature, and relative humidity for healing were maintained at $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $25^{\circ}C$, and 90%, respectively. There was no significant difference in graft-taking of grafted cucumber seedlings according to light quality except the blue LED with the blink cycle of 5s/5s. Regardless of the blink cycle, there was no significant difference in graft-taking of cucumber seedlings healed under red, blue+red, and white LED modules. These results implied that the effects of light quality and blink cycle on the graft-taking were not significant. Differences in the leaf length, leaf area, and fresh weight of cucumber seedlings healed blue or red LED with the blink cycle of 9s/1s were found to be significant. There was no significant effect of the blink cycle on the growth of cucumber seedlings healed under white LED modules. The prices of white LED are gradually falling due to increased demand. Considering the manufacturing unit price of white LED modules, the cost savings of 10-15% are expected as compared to the conventional blue/red LED modules. Therefore, it was concluded that the use of white LED modules will be economical as an artificial lighting sources for healing of grafted seedlings.