• Journal of Ginseng Research
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• v.6 no.1
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• pp.38-45
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• 1982

To determine the optimum light intensity for growth of ginseng plants, change of temperature, moisture content in son, occurrence alternaria blight, defoliation rate, chlorophyll contents, and growth of shoots and roots were investigated under different light intensity such as 5%, 10%, 20% and 30% light transmittance rare(L.T.R.). The results obtained were as follows. 1. Maximum temperature under the shading was increased as the increase of light intensity, whereas soil moisture content decreased 2. As the increase of light intensity, stem and Peduncle length, leaf area, and chlorophyll contents decreased significantly but length and width of the leaf was not significant, while stem diameter, special leaf weight and chlorophyll a/chl. b ratio increased 3. Stem color was shown dark purp!e as the increase of light intensity. 4. Photosynthesis during the day was highest at 9 A.M. and decreased as time passed in all plots. The means of photouynthesis during the day showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for highest photosxthesis was 18.4% L.T.R. by theoritical equation. 5. It was showed a tendency that alternaria leaf blight of ginseng plants was increased as the increase of light intensity. 6. Defoliation rate of ginseng plants was increased as the increase of light intensity, especially all plants were defoliated by late June without shading. 7. Yield percentage of the rear line was increased as the increase of light intensity. Root weight per plant showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for the best yield was 18.5% L.T.R. by theeritical equation.

• Journal of Ginseng Research
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• v.15 no.1
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• pp.31-35
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• 1991

In order to know the optimum planting density under shading structures at different light intensity, We investigated the growth status, distribution of ginseng leaf area, correlation between planting density and root weight per plant and yield, correlation between leaf area index and root weight per plant and yield. According to the increase of planting density the leaf area per plant was decreased, but leaf area index (L.A.I) was increased. Ginseng leaf population at different lines under common straw shading were distributed mainly in frost lines but polyethylene net shading at 10fo light intensity were distributed equally in all lines. Optimum planting density in common straw shading at 5% light intensity was 55 plant per tan (90 cmX180 cm) and polyethylene net shading 81 10% light intensity was 60 plant per tan, in consideration of root weight and yield. Optimum leaf area index was 2.4 under common straw shading at 5% light intensity but was 2.7 under polyethylene net shading at 10% light intensity.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.591-597
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• 2000

This studies were carried out to investigate the optimum shading for seedling cultivation of Cornus controversa and C. walteri. The experiment was performed under five different shading scheme such as 100%, 50%, 30%, 10%, and 2% of the natural full sun light intensity for 7 months in the field condition. Two species showed the highest height growth under 50% of relative light intensity, and the highest diameter growth at root collar was observed both under 100% and 50% of relative light intensity. C. controversa seedlings grown under 50% of relative light intensity produced more total biomass than control seedlings, but root biomass was less in the seedlings under 50% of relative light intensity. In case of C. walteri, total biomass production of the seedlings under 50% of relative light intensity was lower than that of the seedlings under full sun light intensity, but leaves and shoot biomass was slightly high under 50% of relative light intensity. Great reductions of height growth and diameter growth at root collar, and biomass production were observed below 30% of relative light intensity in the both species. T/R ratio of the two species was highest under 30% of relative light intensity, and the chlorophyll content of the seedlings tended to be increased by reduction of relative light intensity.

• Journal of Ginseng Research
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• v.6 no.2
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• pp.149-153
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• 1982

To investigate the effect of light intensity on the growth of shoots and roots, water and chlorophyll contents in the ginseng leaf were determined at 5%, l0%, 20%, 30% light transmittance rate (LTR) with 1,2 and 4 year-old ginseng plants in the field. Stem length, size of the leaf, water and chlorophyll contents were decreased as the increase of the light intensity in all ages of ginseng plants. The degree of decrease was severe in the one year-old ginseng compared to that of 2, or 4 year-old ginseng, while there was no difference between the 2 and 4 year-old plants. Root weight per plant was highest at 5% LTR in the one year-old plants, while it was at 20% LTR in the 2 and 4 year-old plants. Generally, demand of light for the growth of one year-old ginseng was lower than those of 2 or 4 year-old plants there was no difference of it among the ginseng plants older than 2 years.

• Journal of Ginseng Research
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• v.8 no.1
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• pp.65-74
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• 1984

This experiment was carried out to study the effects of light intensity and soil water regimes on the growth of ginseng seedling. The results were as follows: 1. The maximum light intensity and optimum temperature in 1,le photosynthesis of ginseng seedling were 10,000 lux and 23 $^{\circ}C$. Respiration rate was increased at high temperature. 2. Air and soil temperature under the shading were increased as the increase of light intensity but soil water contents were decreased as the increase of light intensity, whereas air and soil temperature were decreased as the increase of precipitation under the shade b5: soil water contents were increased as the increase of precipitation under the shade. 3. The higher the transmittance of the shade, the greater the specific leaf weight (S.L.W.) and stomatal density. In contrast, however, the contents of total chlorophyll, chlorophyll a and b, and stomatal length was decreased. There was no any significant difference light intensity of the a/b ratio of chlorophyll. 4. The highest photosynthesis was occurred in ginseng leaves grown under the shade 5% L.T.R. and net photosynthesis rates increased with increasing soil water contents. 5. Optimum condition for usable seedling yield were 5% L.T.R. and 3.3% precipitation under the shade. Useless seedling increased with increasing precipitation under the shade.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.630-636
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• 2012

The purpose of this study was to determine optimum wavelength, light intensity, aeration rate, and temperature for the cultivation of Dunaliella salina illuminated by various types of light emitting diode. Growth rates of Dunaliella salina were faster at higher temperature than the growth rate at lower temperature. Among the culturing temperatures, $22^{\circ}C$ was the optimum temperature for the growth of Dunaliella salina. White LED was the most efficient light source and lower light intensity (3,000 Lux) resulted in better biomass production (1.30 g/L). The value of aeration varied between 0 and 2.4 vvm at the illumination of 3,000 Lux of white light emitting diode. Highest specific growth rate of $1.12day^{-1}$ was obtained at no-aeration and lower specific growth rates were obtained for other aeration tests, which indicated that aeration could be harmful for the cultivation of Dunaliella salina.

• KSBB Journal
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• v.28 no.3
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• pp.170-176
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• 2013

The purpose of this study was to determine optimum condition of Pavlova lutheri and Phaeodactylum tricornutum. Detailed studies were carried out on the effects of various wavelengths of light-emitting diodes (LEDs), light intensities and air flow rations. For the Pa. lutheri, cell growth rates and maximum cell concentrations were similar regardless of wavelengths and air flow rates. Among the different light intensities, cell concentration increased when light intensity of red LED increased. For Ph. tricornutum, red LED was found to be the most effective light source, and light intensity of 3,100 Lux resulted in the most effective for the cultivation of Ph. tricornutum. Different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. Aeration of 0.8 vvm was determined to be the optimum aeration rate for the cultivation of Ph. tricornutum. Especially, five and two times greater cell concentrations of Pa. lutheri and Ph. tricornutum, respectively, were observed when air was applied.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.446-451
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• 2008

The growth of Porphyridium cruentum and its porphyran polysaccharide production were measured as functions of light intensity, temperature, light quality (fluorescent, blue, red, and green) and nitrate concentration. The optimum light intensity, temperature, and nitrate concentration for the growth of Porphyridium cruentum and for its polysaccharide production were 1,400 lx, $25^{\circ}C$, and 0.03%, respectively. The maximum cell concentration and polysaccharide content under the optimum conditions were 1.95 and 0.23 mg/mL, respectively. Light quality did not influence growth or polysaccharide production. The best results for growth and polysaccharide production were obtained using fluorescent light.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.671-676
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• 2011

To determine the optimum light intensity for mass culture of the brackish-water cyclopoid copepod Paracyclopina nana, survival, growth, and productivity of the copepod were examined at several light intensities (0, 10, 100, 500, 1,000 lx). The survival rate of P. nana from nauplius to adult decreased with increasing light intensity. The highest survival rate was found under the dark condition, with 61.7% surviving; no significant difference was observed between 0 and 10 lx (51.7%) and the lowest survival rate was with 100 lx (26.7%). Survival rates at 500 and 1,000 lx were significantly lower in comparison with other conditions. The developmental period from nauplius to copepodid (5.8 days) and to adult (11.8 days) at 10 lx was significantly shorter than in the other treatments. Daily mean nauplius production of adult females over 7 days at 0, 10 and 100 lx was significantly higher than at 500 and 1,000 lx. In the 1,000 lx treatment, 99% of the adult females died on the $14^{th}$ day. The optimum light intensity for the mass culture of P. nana could be 10 lx, which had no adverse effects on survival, development, or reproduction.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.7-11
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• 1996

This study was conducted to know the effects of light intensity and temperature on growth of V. fauriei plants. Photosynthesis of V. fauriei had highly significant relations to light intensity and temperature in a quadratic regression model, from which the optimum light intensity and temperature for the plant growth were estimated to be 40,000lux and $17.7^{\circ}C.$ Root was produced less by shading at Jinbu where is located in alpine region, but root yield is increased by shading at Umsong where is located in plane region. Roots were produced more in Jinbu than in Umsong. A highly significant quadratic regression was noted between temperature and leaf width or root weight of V. fauriei. It was estimated from the regression equation that the optimum temperature for root growth was $20.3^{\circ}C.$