• Horticultural Science & Technology
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• v.34 no.6
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• pp.878-885
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• 2016

A study was conducted to examine the effects of light quality on the growth and phytochemical contents of ice plant in a closed-type plant production system. Seeds were sown in a 128-cell plug tray using rockwool. The seedlings were then transplanted into a deep floating technique system with recirculating nutrient solution (EC $1.5dS{\cdot}m^{-1}$, pH 6.5) in a closed-type plant production system. The nutrient solution was supplied at two weeks after transplanting with 2.0 mM NaCl concentration in all treatments for the development of the bladder cells. The three light sources with different light qualities used were as followed; FL (fluorescent lamps), combined RW LED (red:white = 7:3), and combined RBW LED (red:blue:white = 8:1:1) at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD with a photoperiod of 14/10 hours (light/dark). The results showed that the FL treatment had the greatest growth enhancement effects on the leaf area and the fresh and dry weights of the shoots and roots. The SPAD values were significantly higher under the FL and RBW LED treatments, at 29.8 and 30.6, respectively. No significant difference was observed in salinity under all treatments. Chlorophyll fluorescence was significantly higher under the FL treatment. The total phenol content and antioxidant activity were the highest under the RBW LED treatment. The total flavonoid content was significantly higher under the RBW LED and FL treatments. Hence, the results indicate that the growth of ice plant was maximized under the FL treatment. The phytochemical contents were maximized under the RBW LED treatment.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.77-82
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• 2016

This study was carried out to investigate the effects of artificial light sources on growth, yield, and glucosinolate content of hydoroponically grown Peucedanum japonicum in plant factory. Treatments were given with LED Blue:White(1:1, B:W), LED Red:Blue:White(2:1:3, RBW), and LED Blue:White(1:1)+Florescent lamp(BW+FL). Number of harvested leaves and leaf weight of BW+FL were higher than BW and RBW. BW+FL in leaf length and RBW in leaf width were significant difference with other treatments. Chlorophyll content and 'L' value were not significant difference among the treatments. The 'a' and 'b' value is the lowest in BW+FL. Glucosinolate content was high in order of glucobrassicin, glucoiberin, sinigrin, gluconasturtiin, progoitrin, glucoraphamin, and epiprogoitrin in all treatments, and total glucosinolate content was the highest in RBW treatment. Moisture, crude protein, crude fat, and ash content of leaves were not different among the treatments. In conclusion, this study showed that light caused growth and secondary metabolites synthesis, and we recommend to further study between light and secondary metabolites for increasing functionality.

• 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.22 no.4
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• pp.392-399
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• 2013

This study aimed to investigate responses of photosynthesis, plant growth, and phytochemical contents to different artificial light sources for 'Seneca RZ' and 'Gaugin RZ' two butterhead lettuce (Lactuca sativa L.). In this study, fluorescent lamps (FL), three colors LEDs (red, blue and white, 5 : 4 : 1; RBW) and metalhalide lamps (MH) were used as artificial lighting sources. Photoperiod, air temperature, relative humidity, EC, and pH in a cultivation system were maintained at 16/8 h, $25/15^{\circ}C$, 60~70%, $1.4{\pm}0.2dS{\cdot}m^{-1}$, and $6.0{\pm}0.5$, respectively. The photosynthetic rate of both two butterhead lettuce were the highest under RBW in middle growth stage. However, in late growth stage, the photosynthetic rate of both two butterhead lettuce were higher under RBW and MH than FL. The light sources showed significant results for plant growth but those effects were different to variety. Fresh and dry weight of 'Gaugin RZ' butterhead lettuce under MH were heavier than other lights in all growth stages. Growth of 'Seneca RZ' butterhead lettuce was maximized highest under MH in middle growth stage and FL in late growth stage. In the leaf tissue of 'Seneca RZ' butterhead lettuce, tipburn symptom occurred under all light sources and in the leaf tissue of 'Gaugin RZ' butterhead lettuce, it occurred under two light sources except for fluorescent lamps in late growth stage. kinds of lamp affect plant growth more than plant quality. Relative growth rate of both two butterhead lettuce was faster in middle growth stage than late stage. Growth of 'Gaugin RZ' was shown by kinds of lamp in middle growth stage and but it was not significantly affected by light sources and variety in late stage. Most of the phytochemical contents of two butterhead lettuce were significantly affected by different light sources. Contents of all vitamins showed higher than other light sources on RBW for both two lettuce, especially ${\beta}$-Carotene content of 'Gaugin RZ' was the highest. Plant growth, photosynthesis, and phytochemical contents were observed significant effects by different light sources for two butterhead lettuce but those effects were highly different between variety and kinds of phytochemicals. Therefore, the selection of optimum light source should be considered by variety and kinds of phytochemicals in the plant factory.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.232-239
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• 2016

The objective of this study was to examine the effect of photoperiod and light intensity of RBW LED (red:blue:white = 2:1:1) on the growth of Taraxacum coreanum Nakai in a fully artificial light type plant factory. 3 photoperiods and 4 light intensity were used respectively in a fully artificial light type plant production system. Plants were cultured with three photoperiods and four light intensity regimes (conditions) for 270 and 120 days, respectively, using nutrient film technique (NFT) or aeroponics culture methods. For each photoperiod, the total leaves per plant harvested 8 times in all cultivation period was 224 in the 16/8(day/light) photoperiod that had no significant difference from 220 in the 12/12 photoperiod and the lowest number of leaves was 151 occurred in the 8/16 photoperiod, which means that the longer photoperiod, the more leaves harvest. Total fresh weight of above ground was the high in order of in 16/8 photoperiod as 125g, 12/12 photoperiod as 91g, 8/16 photoperiod as 56g. For each light intensity, the total leaves per plant harvested 4 times in all cultivation period was the great in order of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 123, $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 107, $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 95, $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 56 which was the smallest number of total leaves harvest. Total fresh weight of above ground per plant was the high in order of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 43.6g, $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 34.6g, $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 32.2g, $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 18.2g. From these results, it was concluded that photoperiod of 16/8 and light intensity at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ can be used as the light condition of RBW LED (red:blue:white = 2:1:1) for optimal growth of Taraxacum coreanum Nakai in a fully artificial light type plant factory.