• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.10-15
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• 1987

The experiment was designed to determine the proper shading rate and shading materials to decrease the excessive dried leaves during cure of burley tobacco. Five shading rates and seaven shading materials were applied on the pipe vinyl house from initial stage or yellow stage of cure. Temperature was lower and weight-loss of leaves delayed with shading from initial stage to browning stage of cure. Excessive dried leave were largely decreased as shading rate was increased to 70%. However, at shading rate more than 70%, its decreasing extent was fewer. Price per kg and physical properties improved considerably at shading rate of 50%. Shading materials alone could not completely prevent excessive dried leaves but it could decrease them. Orange, white and purple color vinyl among shading materials had so effects of shading as the black shading cloth during curing. However, white color vinyl didn't endure more than a few months due to sunshine. A difference of light quality in visible light was no significance on air curing.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.261-268
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• 1992

The membranes of mitochondria and chloroplasts contain a number of pigments that can act as endogenous sensitizers to produce activated oxygen species, most efficiently in blue light, which, in turn, attack functional targets in membranes. Therefore, intense blue light from the sun can exert various adverse effects on the functional and structural integrity of the membranes: one of the biochemical events of these negative effects could be the oxidative degradation of the unsaturated fatty acid constituents of membrane polar lipid. It may be assumed that as a strategy to avoid the light induced fatty acid degradation in membranes plant cells, responding to high intensity blue light, change the fatty acid compositions of membrane lipid in such that more-unsaturated fatty acid constituents are replaced by lessunsaturated fatty acid constituents. The results obtained in the present study, most importantly the measurements of double bond index of membrane polar lipid in concert with other measurements such as light quaility-dependent membrane peroxidation and the activities of membrane-bound proteins, seem to support this assumption.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.253-260
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• 1992

A photoresponse that results in organisms dispersing from a region of bright light. generally termed photodispersal, is frequently observed in some fishes notably including mud fish (Misgurunus mizolepis G${\"{U}}$NTHER). The primary assumption for this study was that the photodispersion may result from the behavioral strategies of fishes aimed to avoid illumination conditions that could injure the cells in skin tissues via photodynamic sensitization reactions. Here we present some preliminary results that seem to support this assumption : (1) the locomotive action of dark-adapted mud fish was triggered by the onset of illumination with light : (2) blue light (400-500nm) was much more effective in bringing about the locomotive activity than yellow (550-650nm) and red (650-800nm) lights : (3) two blue light absorbing pigments, which photogenerate activated oxygen species, were separated from the skin tissues of mud fish, one of these being identified as riboflavin.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.142-147
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• 2015

The artificial light sources for growth of plant are usually high-pressure sodium lamp, metal haloids lamp, and fluorescent light; however, these light sources have relatively weaker Red and Blue lights that are necessary for growth of plants. Especially the effect of Photosynthetic Photon Flux Density (PPFD) is pointed out as the weakness. Meanwhile, LED light source can be selected by specific wavelength to greatly improve the effect of PPFD. In this regard, this paper aims to investigate the promotion of plant growth by measuring photosynthetic photon flux density (hereafter referred to as PPFD) according to changes in light quality of the LED light sources. Towards this end, LED light sources for plant growth were produced with 4 kinds of mono-chromatic lights and 6 kinds of combined lights by mixing red, blue, green and white lights. A comparative analysis was conducted to investigate the effects of optical properties and PPFD on plants (green leaf lettuce) using the produced light sources. The results monochromatic light has fastest growth rate, but plant growth conditions have poor. This being so, mixed light is suitable for the green leaf lettuce.

• Korean Journal of Plant Resources
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• v.11 no.2
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• pp.124-130
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• 1998

It failed occasionally to take a reasonable emergence rate since tobacco (Nicotiana tabacum L.) seeds were planted on late Jan. showing lowest temperature. This experiment was done to measure the effect of GA3 (concentration ; period) , light quality (red ; white ; dark) during or after its treatment, daily irradiation hours( 0 ; 8 ; 12 ;16) and germination termperature (20 or 10 $^{\circ}C$ ocnstant ; 20/1$0^{\circ}C$ alternating) on the germination rate. Red and white light given during grmination showed no differences between the other daily irradiation hours except that 8 hours red light delayed germination although their 12 hours irradiation had the gratest rate. The rate was increased with increased concentration to GA3 0.01 mM or increased imbibition period to 3 days although the rate of cv. NC 82 was less than that of cv. Burley 21 in the case of dark imbibition of GA3 but daily 12 hours irradiation during germination. Light quality forced during GA3 imbibition eliminated such effect of GA3 shown in the darkness so that only light quality pretreatment and termperature during germinition were affected on the rate. The germination rate of thecultivars was decreased in the order of red, white light, darkness meaning that it was highly influenced by the light quality during GA3 treatment. Regardless of GA3 or light quality treatment,on the other hand, the rate was greater in 20 $^{\circ}C$ constat than 1$0^{\circ}C$ constant and 20/1$0^{\circ}C$ alternating germination temperature having similar germinative patterns.

• Journal of Ginseng Research
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• v.15 no.2
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• pp.144-151
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• 1991

This study was conducted to elucidate the effects of light intensity using polyethylene (p.E) net shading on the specific gravity, red ginseng quality, sugar and saponin contents of ginseng root. The specific gravity significantly increased in the ginseng roots grown under the P.E net shading as compared with that of common straw shading. The red ginseng quality under the P.E net shading was improved in order of 10, 5, 15, 20, 30% of light intensity and the inside cavity and inside white part decreased remarkably as compared with those of common straw shading. The ginseng roots grown under the P.E net shading at 10% and 15% light intensity showed a significant increase in the total sugar content but a significant decrease in the reducing sugar content at 15% light intensity as compared with those of common straw shading. The amount of total saponin of ginseng roots was increased under the P.E net shading at high light intensity as compared with that of common straw shading and the ginseng roots grown under the P.E net shading at 10% light intensity showed an increase in the diol group saponin but the ratio of PT/PD was decreased. Extract contents of ginseng root under the P.E net shading was higher than those of common straw shading and the roots grown under the P.E net shading at 15% and 20% light intensity resulted in a remarkable increase in extract contents.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.8-10
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• 1978

After growing the hot pepper fruits in polyethylene film(PE) house covered with white or red colored film, the fruits were collected and chlorophyll, carotenoid, and capsaicin content was analyzed. Although total chlorophyll content was higher in fruit of white PE house$(208.9{\mu}g/g-F.W)$ as compared to that of red PE house $(153.0{\mu}g/g-F.W)$ grown plants, the ratio of chlorophyll a over b were similar, giving 2.15 and 2.13 respectively in white and red PE house. Total carotenoid, $\beta$-carotene and the capsaicin content were higher in fruits of red PE house grown plants. Therefore, it is suggested that red film could be used as a successful covering material for poly ethylene film house.

• The Korean Journal of Mycology
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• v.17 no.4
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• pp.189-193
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• 1989

Ganoderma lucidum formed uniquely non-basidiocarpous basidiospore (NBB) from the aerial mycelia on agar media without the normal basidiocarps. Light was necessary for NBB formation. Best sporulation was obtained at the periodic exposure of 16 hour light and 8 hour darkness for more than 8 days. Effective wave length was blue and yellow but non sporulation was induced by near U.V. light. Effective light intensity for NBB bearing appeared to be about 1,000 Lux as white light. Photomorphogenetic responses in Ganoderma lucidum were clearly different among strains of the fungus.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.270-278
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• 2021

BACKGROUND: Horticultural plant growth under field and/or greenhouse conditions is affected by the climate changes (e.g., temperature, humidity, and rainfall). Therefore investigation of hydroponics on field horticultural crops is necessary for year-round production of the plants regardless of external environment changes under plant factory system with artificial light sources. METHODS AND RESULTS: Common sage (Salvia plebeia), nasturtium (Tropaeolum majus), and hooker chive (Allium hookeri) plants were hydroponically culturing in the plant factory with blue-red-white LEDs (Light-Emitting Diodes) and fluorescent lights (FLs). Leaf numbers of common sage under mixture LED and FL treatments were 134% and 98% greater, respectively than those in the greenhouse condition. In hooker chives, unfolded leaf numbers were 35% greater under the artificial lights and leaf elongation was inhibited by the conventional sunlight compared to the artificial light treatments. Absorption pattern of NO₃-N composition in hydroponic solution was not affected by the different light qualities. CONCLUSION(S): Plant factory system with different light qualities could be applied for fresh-leaf production of common sage, nasturtium, and hooker chive plants culturing under field and/or greenhouse. Controlled light qualities in the system resulted in significantly higher hydroponic growth of the plants comparing to conventional greenhouse condition in present.

• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.14-20
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• 2023

Light is an important factor that influences the growth and development of flowering plants. The present study investigated the effects of in vitro acclimatization to different light colors (white light (WL; control), blue light (BL; 447 nm), green light (GL; 519 nm), and red light (RL; 667 nm)) on the growth of petunia (Petunia hybrida) and of hardening cultivation of plant transferred form in vitro to a greenhouse under sunlight. Compared to the control, the shoot length and leaf width of Petunia increased by 42% and 11.7%, respectively, after acclimatization to BL and the shoot growth increased by 29.3% after acclimatization to RL. The chlorophyll and carotenoid contents after acclimatization to BL and GL were 16.7% and 11.3% higher, respectively, and 14.4% and 11.9% higher, respectively, than those in the control. During greenhouse cultivation, the shoot length increased by 16.7% and 11.3%, respectively, after acclimatization to BL and RL, respectively, and the leaf length and leaf width increased by 14.4% and 11.9%, respectively, after acclimatization to GL. While dry weight of root of GL and BL was not significant difference in vitro, increased by 59.0% and 22.9% ex vitro than that of WL. Thus, acclimatization to BL increased the shoot growth and leaf chlorophyll contents, and acclimatization to GL and RL enhanced shoot and root growth, in petunia.