• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.10
• /
• pp.14-22
• /
• 2011

The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

• Journal of Applied Biological Chemistry
• /
• v.64 no.4
• /
• pp.351-356
• /
• 2021

Changing environmental conditions can affect plant growth by influencing water and nutrient transport and photosynthesis. Plant physiological responses under changing environmental conditions can be non-destructively monitored using electrodes as plant induced electrical signal (PIES). Objective of the study was to monitor PIES in response to increased CO₂ and decreased photosynthetic photon flux density (PPFD). The PIES increased during day time when transpiration and photosynthesis occurs and monitored CO₂ concentration was negatively correlated to the PIES. Enhanced CO₂ concentration slightly reduced PIES, but the effect of increased CO₂ was limited by light intensity. The effect of reduced PPFD was not appeared immediately because water and nutrient transport was not promptly affected by the light. The study was conducted to evaluate short-term effect of increasing CO₂ and decreasing PPFD, hence proline content and chlorophyll fluorescence was not significantly affected by the conditions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.333-338
• /
• 2021

This study determined the characteristics of LED illumination and photosynthetically active radiation flux density (PPFD) for LED lighting design in an indoor plant factory. This was done based on the light wavelength and PPFD intensity required for plant growth. It has been found that the wavelength and intensity are decreased according to the measuring distance, and green light has an important role in illumination characteristics, while blue light has an important role in the PPFD characteristics. Considering only the photosynthetic properties of plants, the effective order of photosynthesis was blue>red>white>green. When the measurement distance was 30 [cm], it was found that reduction levels of 60 [cm], 90 [cm], and 120 [cm] decreased to about 36 [%], 18 [%], and 10 [%], respectively. As a result of the characteristics of mixed light (red:blue=2:1, 3:1, 4:1) and the measurement distance, when the measured value at 30 [cm] is 100%, the measured value at 120 [cm] is 10-11 [%]. From the obtained results, an optimal structure was proposed for maximizing the light efficiency of an indoor greenhouse for future research.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.32 no.4
• /
• pp.1-6
• /
• 2004

This study was carried out to investigate the effects of light intensities on the growth and net photosynthesis of Piper kauzura under different shading levels : 0％, 50％, 70％ and 90％ of sunlight. Mortality rate was lowest under a 70％ shading level but 0％ and 90％ shading levels were about 46％ and 53％ each respectively. Plant height was shorter and leaf size was smaller and yellowish under a 0％ shading level but increased when light intensity was decreased. However, under a 90％ shading level, growth of Piper kauzura was inferior to other treatments. Top fresh weight was about 11.24g under a 50％ shading level and about two times higher than that observed in about 6.6g under a 90％ shading level. Root fresh weight was about 7.7g under a 0％ shading level and was about two times higher than that showed in about 3.84g and 3.64g under 90％ and 70％ respectively. Total chlorophyll content and chlorophyll a/b rate were increased when light intensity was decreased. Net Photosynthesis achieved the highest under a 70％ shading level and maximum photosynthetic photon flux density was 150 molㆍm/sup -2/ㆍs/sup -1/. Therefore, growth of Piper kauzura was good under 50∼70％ shading, Meaning that it is an indoor plant that could be highly utilized.

• Journal of Environmental Science International
• /
• v.27 no.10
• /
• pp.821-829
• /
• 2018

This study was conducted to examine the influence of Light-Emitting Diode (LED) light quality in urban agricultural plant factories on the growth and development of Seolhyang strawberry daughter plants in order to improve the efficiency of daughter plant growth and urban agriculture. LED light quality by demonstrated that above-ground growth and development were greatest for daughter plant 2. Daughter plant 1 showed the next highest growth and development, followed by daughter plant 3. Among the different qualities of LED light, the stem was thickest and growth rate of leaves was highest for R + B III (LED quality: red 660 nm + blue 450 nm/photosynthetic photon flux density (PPFD): $241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R (red $660nm/115-117{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). Plant height, leaf width, petiole length, and the leaf growth rate were highest for W (white fluorescent lamp/$241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R + B I (red 660nm+blue 450nm/$80-82{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). For above-ground growth and development, as the plants surpassed the seedling age, mixed light (red + blue), rather than monochromatic light (red or blue), and higher PPFD values tended to increase development. Regarding the quality of the LED light, daughter plant 2 showed the highest chlorophyll content, followed by daughter plant 1, and daughter plant 3 showed the least chlorophyll content. When the wavelength was monochromatic, chlorophyll content increased, compared to that when PPFD values were increased. Mixed light vitality was highest in daughter plant 2, followed by 1, and 3, showed increased photosynthesis when PPFD values were high with mixed light, in contrast to the results observed for chlorophyll content.

• Journal of Plant Biotechnology
• /
• v.41 no.3
• /
• pp.123-126
• /
• 2014

This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

• Korean Journal of Environment and Ecology
• /
• v.26 no.1
• /
• pp.82-90
• /
• 2012

In this study, we investigated the environmental factors and growth characteristics of Sasa borealis community inside a temperate deciduous forest and reviewed its effect on the lower vegetation and natural regeneration. The S. borealis community in the Jungsan-ri region of Jirisan National Park was chosen as the study area, and the vegetation and the environmental factors were investigated. The dominance value, height and foliage layer thickness were investigated as the growth characteristics of S. borealis in the area. As the environmental factors, we investigated the photosynthesis photon flux density (PPFD) of the shrub and ground layers as well as the chemical characteristics of the soil. Additionally, we investigated the flora on the ground layer of the area as well as the number and height of woody plants. The result showed that the height and foliage layer thickness of the S. borealis was closely related to the light conditions but the distribution was not determined simply by the effect of the environment or vegetation of the particular area. This may be deeply related with the unique survival strategy of S. borealis, a vegetably propagated plant, that it can extensively distributed on a heterogeneous resources environment in a forest as multiple culm are interconnected with each other through the rhizomes. The dense dominance and great height of S. borealis reduced the plant species diversity in the ground layer by decreasing the PPFD on the ground surface.

• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.6
• /
• pp.705-711
• /
• 2015

Management of soil water and fertilization is known to primarily affect physiological properties and yield in plant. The effect of soil water potential and nitrogen application on characteristics of photosynthesis and chlorophyll fluorescence in Schisandra chinensis Baillon was investigated on a sandy loam soil. Net photosyntheis rate and transpiration rate increased as a photon flux density and was highest at -50kPa of soil water potential. Light compensation point ($1.5{\mu}molm^{-1}s^{-1}$) and dark respiration ($0.13{\mu}molCO_2m^{-1}s^{-1}$) was lowest at -50 kPa but maximum photosynthesis rate ($13.10{\mu}molCO_2m^{-1}s^{-1}$) and net apparent quantum yield ($0.083{\mu}molCO_2m^{-1}s^{-1}$) was highest at -50 kPa. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII) and PIabs was higher in treatments of -50 kPa and -60 kPa respectively, which reflects the relative reduction state of PSII. But the relative activities per reaction center such as ABS/RC and DIo/RC were low with decreasing soil water potential. Net photosyntheis rate and transpiration rate were highest at treatment of soil testing 1.0 times ($92kgha^{-1}$). Application of nitrogen resulted in high Fv/Fm, $PI_{abs}$ and low ABS/RC, DIo/RC. This result implies that -50 kPa of soil water potential and nitrogen fertilizer may improve the efficiency of photosynthesis through controlling a photosystem in Schisandra chinensis Baillon.

• Journal of Korean Society on Water Environment
• /
• v.38 no.6
• /
• pp.282-291
• /
• 2022

Since the efficiency of wastewater treatment using microalgae differs depending on the metabolic characteristics of the species, it is important to understand the characteristics of target algae prior to the application in wastewater treatment. In this study, for the application of Arthrospira platensis to wastewater treatment, which is a filamentous alkaliphilic cyanobacteria, basic species specificity was identified and the possibility of application to wastewater treatment was investigated. As a result of the species specificity investigation, the specific growth rate between pH 7.0 and 11.0 showed the highest value near pH 9 at 0.25/day. The reason for the relatively low growth(0.08/day) at pH 11 was thought to be the CA(carbonic anhydrase) enzyme that is involved in carbon fixation during photosynthesis has the highest activity at pH 8.0 to 9.0, and at pH 11, CA activity was relatively low. In addition, A. platensis showed optimal growth at 400 PPFD(photosynthetic photon flux density) and 30℃, and this means that cyanobacteria such as A. platensis have a larger number of PS-I(photosystem I) than that of PS-II(photosystem II). It was speculated that it was because higher light intensity and temperature were required to sufficiently generate electrons to transfer to PS-I. Regarding the applicability of A. platensis, it was suggested that if a system using the synergistic effect of co-culture of A. platensis and bacteria was developed, a more efficient system would be possible. And different from single cocci, filamentous A. platensis expected to have a positive impact on harvesting, which is very important in the latter part of the wastewater treatment process.

• Korean Journal of Agricultural Science
• /
• v.41 no.4
• /
• pp.321-326
• /
• 2014

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas 'Manchu' were sowed and managed under a growth room chamber. The environmental conditions (temperature $22^{\circ}C/18^{\circ}C$ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) $120{\pm}6{\mu}mol\;m^{-2}s^{-1}$) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) ${\times}$ 800 (W) ${\times}$ 400 mm(H)] under $150{\pm}5{\mu}mol\;m^{-2}s^{-1}$ PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, $CO_2$ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to $200{\mu}mol\;m^{-2}s^{-1}$. Though $CO_2$ saturation point was around $1000-1200{\mu}mol\;mol^{-1}$, increase in air temperature from 16 to $26^{\circ}C$ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and $CO_2$ concentration for environment are controlled at $20{\pm}3^{\circ}C$, $150{\mu}mol\;m^{-2}s^{-1}$, and around $1000{\mu}mol\;mol^{-1}$ for mass production.