• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.149-157
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• 2008

We investigated chlorophyll contents and growth performances of five deciduous hardwood species growing in central temperate zone of Korean forest. Cornus controversa, Fraxinus rhynchophylla, Betula schmidtii, Prunus leveilleana, and Acer mono seedlings were grown under four different light intensity regime (full sunlight, $65{\sim}72%$, $29{\sim}40%$, and, $7{\sim}12%$ of the full sunlight) for the experiment. The chlorophyll contents of all of the species were highest in $7{\sim}12%$ of the full sunlight, while lowest under the full sunlight. The relative growth rate of root collar diameter and height were decreased with increasing shading level except for Acer mono that showed the highest relative growth rate under $29{\sim}40%$ of the full sunlight. Total biomass and root volumes of the seedlings studied decreased as the light intensity decreased with different shade levels. For Acer mono, however, the biomass and root volumes were highest in $29{\sim}40%$ of the full sunlight. The relative growth rate of root comparing to shoot decreased as shading increased, and as a result, the ratio of aboveground to belowground biomass increased. As the shading level increased, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) of most species increased.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.200-206
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• 2003

Pleurotus eryngii(King oyster) is one of the most promising mushrooms produced on the domestic farms. The quality as well as quantity of Eryngii is sensitively affected by micro climate factors such as temperature, relative humidity, $CO_2$ concentration, and light intensity. To safely produce high-quality Eryngii all the year round, it is required that the environmental factors be carefully controlled by well designed structures equipped with various facilities and control systems. At the commercial mushroom cultivation house(A,B), this study was carried out to find out reasonable range of each environmental factor and yield together with economic and safe structures influencing on the optimal productivity of Eryngii. this experiment was conducted for about two-month from Nov. 11, 2002 to Dec. 30, 2002 in Eryngii. cultivation house-A, B. Ambient temperature during the experiment period was not predominantly different from that of a normal year. The capacity of the hot water boiler and the piping systems were not enough. Maximum air temperature difference between the upper and lower growth stage during a heating time zone was about 2~3$^{\circ}C$. The max. and min. relative humidity were ranged approximately 60~100%, and average relative humidity was ranged approximately 80~100%. And $CO_2$concentration increased until maximum 1,600~1,800 ppm with the passing growing period. The illuminance in cultivation house was widely distributed from 20lx to 160 lx in accordance with position, and it was maintained lower than the recommended illuminance range 100~200 lx. The average yield per bottle was about 67~85g. But the optimal productivity will be evaluated by considering the quality and quantity of mushroom production, energy requirements, facility construction and management cost, etc.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.34-38
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• 2015

This research was conducted to establish efficient methods to overcome high temperature and low humidity with light selective shading agent and two-fluid fogging system in greenhouses in hot season. There were four experimental treatments; not treated (Non), fogging by two-fluid fogging system (Fog), spraying onto the greenhouse surface with shading coating agent (Coat), and using fogging and coating together (F&C). The amount of solar radiation entered into the greenhouses was higher in Non, and then Fog, Coat, and F&C in descending order. Fog was more efficient to lower the air temperature and also raise relative humidity than Coat treatment. The crop temperature was about $6^{\circ}C$ higher in Control than the other treatments. F&C revealed as the most efficient method to control the environment inside the greenhouse, but fogging system seemed to be more economic. In stand-alone greenhouses spraying coating agent may be the appropriate choice because of their structural limitations, mainly eave height.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.1
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• pp.58-65
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• 1981

This study was carried out to investigate the influence of distance of planting holes (51, 45, and 40 cm) and number of plants per a hole(4, 5, 6 plants) on agronomic characteristics, yield, and quality of an aromatic tobacco, Sohyang. The results are as follows: 1. Relative light intensity increased by widening the distance of holes. 2. Leaf area per a plant or per a leaf, and leaf length and width increased by widening the distance of holes and decreased by increasing the number of plants per a hole. But L. A. 1. increased by increasing the number of plants per a hole. Leaf shape index (Leaf length/Leaf width) showed little differences among treatments. 3. Dry weight of leaf, root, and stem per a plant decreased by increasing the number of plants per a hole. 4. Total nitrogen decreased by increasing number of plants per a hole and in the case of narrow distance of holes, but nicotine, reducing sugar, ether-extract and ash showed little differences. 5. Yield per 10a decreased by widening the distance of holes. 6. Quality(price per kg) was improved by increasing the number of plants per a hole at the Plot of 51m distance of holes. But there was no variation at the Plot of 45cm. And quality was decreased at the plot of 40cm distance of holes by increasing the number of Plants per a hole. 7. Price per 10a was highest in the plot of which plant spacing was $90\times$40cm and the number of plants per a hole was 4 (11112 plant/10a).

• ALGAE
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• v.29 no.4
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• pp.321-331
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• 2014

Vertebrata lanosa is an abundant and obligate red algal epiphyte of Ascophyllum nodosum that forms part of a complex and highly integrated symbiotic system that includes the ascomycete, Mycophycias ascophylli. As part of ongoing studies to resolve interactions among species in the symbiosis, we used pulse amplitude modulation fluorimetry of chlorophyll a fluorescence, from photosystem II (PSII), to measure the maximum quantum yield ($F_v/F_m$) of PSII [$QY(II)_{max}$] and relative photosynthetic electron transport rates (rETR), as a function of light intensity, in order to evaluate the photosynthetic capacity of the two algal symbionts in the field and in the laboratory under different treatments. Our primary question was 'Is the ecological integration of these species reflected in a corresponding physiological integration involving photosynthetic process?' In the laboratory we measured changes in $QY(II)_{max}$ in thalli of V. lanosa and A. nodosum over one week periods when maintained together in either attached or detached treatments or when maintained separated from each other. While the $QY(II)_{max}$ of PSII of A. nodosum remained high and showed no significant variation among treatments, V. lanosa showed decreasing performance in the following conditions: V. lanosa attached to A. nodosum, V. lanosa in the same culture, but not attached to A. nodosum, and V. lanosa alone. These results are consistent with observations in which rETR was reduced in V. lanosa maintained alone versus attached to A. nodosum. Values for $QY(II)_{max}$ in V. lanosa measured in the field in fully submerged thalli were similar to those measured in the laboratory when V. lanosa was attached to it obligate host A. nodosum. Our results provide evidence of a physiological association of the epiphyte and its host that reflects the known ecology.

• Korean Journal of Medicinal Crop Science
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• v.12 no.3
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• pp.231-236
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• 2004

Crop productivity would be determined by relative capacity of source and sink. The study was carried out to measure the effects of shading and flower bud pinching on growth and yield of Atractylodes japonica Koidz. Shading treatment after transplanting was done at 100%, 65, 45 or 25% level of natural light intensity but the pinching treatment was to remove all the inflorescences formed after June 10, July 10, August 10 or none. Growth and yield at early and late stages were periodically measured. At the early stage, shading mainly influenced fresh weight rather than morphological characters. At the late stage, however, severer shading decreased numbers of stems, leaves, roots, fraction and total fresh weight. 65% shading from July 1 to September 30 after skipped the emerging and early growth stages showed nearly same growth and morphological characters but more rhizome yield per unit area than non-shading. In flower bud pinching treatment, earlier pinching increased number of roots, fraction fresh weights per plant and rhizome yield per unit area.

• The Korean Journal of Ecology
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• v.14 no.4
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• pp.449-455
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• 1991

The water striders, gerris paludum insularis larvae which were fed with the drosophila melanogaster cultured on the appli diet and artificial diet, were reared in the growth cabinet controlled as the two constant temperature regimes of 25 c and 30 c under the condition of photoperiod 16l : 8d, light intensity 510 240 lux, relative humidity 65 3%, and in the natural state. The effects of temperature and diet on the devolopment of g. paludum insularis were analyzed and the results were summarized as follows. 1. The total developmental period of the water strider larvae fed with the d. melanogaster reared on the apple diet at the natural stste was the longest 40 days, and the total devopmental periods at 25 c and 30 c were 35 days and 27 days respectively. The tolal developmental period of larvae fed with d. melanogaster reared on the artifical diet at 25 c was the longest 42 dats, and the total developmental periods at natural stste and 30 c were 32 days and 27 days, respectively. 2. In the larval developmental stages, the fifth stage was longer than that of any stage. The duration of egg stage which was not influenced by diet at 25 c was the longest. 3. The water strider larvae fed which the d. melanogaster reared on the artificial diet at 25 c did not complete their devolopment. 4. No significant difference was odserved in the developmentperiod for diet at 30 c. but, there were significant differences in developmental periods for diet at 25 c and natural state. 5. The rate of adult emergence on the apple diet was higher than that of the artificial diet was higher than of the artificial diet. 6. The shapes of the survivorship curve were convex-curve. 7. The development periods of the larval stages of water striders might be affected to temperature and diet dependently.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.501-505
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• 2020

Objective: The purpose of this study was to investigate the effects of aging methods (AM) i.e. dry-aging (DA) and wet-aging (WA) on the physicochemical properties and in vitro digestibility of proteins in beef short loin. Methods: Short loins (M. longissmus lumborum), were trimmed and boned-out on the fifth day postmortem, from a total of 18 Hanwoo, which were purchased from a commercial slaughterhouse. Short loins were separated randomly grouped into one of the three treatments: control, WA (1℃, 7 days), and DA (1℃, 0.5 m/s, 85% relative humidity [RH], 30 days). Results: Dry-aged beef (DAB) exhibited higher pH, water holding capacity (WHC), myofibrillar fragmentation index (MFI), and digestibility, however lower lightness, redness, and yellowness values, cooking loss, and shear force (SF), than those of wet-aged beef (WAB) (p<0.05). The myosin light chain band intensity of DAB was higher than that of control and WAB in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The in vitro digestibility of aged beef was highly (p<0.001) correlated to physicochemical properties except WHC. The correlation coefficient between AMs and WHC was higher than that between AM and SF (p<0.05) or MFI (p<0.001). A high correlation was observed between SF and MFI (p<0.001). Conclusion: Thus, we believe that DAB is more advantageous than WAB owing to its high digestibility and WHC and low SF.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.200-200
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• 2017

Salinity stress is one of the most important abiotic stresses and severely impairs plant growth and production. Root is the first site for nutrient accumulation like as $Na^+$ in the plant. To investigate the response of wheat root under salinity stress, we executed the characterization of morphology and analysis of metabolites. Wheat seeds cv. Keumgang (Korean cultivar) were grown on the moist filter paper in Petri dish. After 5 days, seedlings were transferred to hydroponic apparatus at 1500 LUX light intensity, at $20^{\circ}C$ with 70% relative humidity in a growth chamber. Seedlings (5-day-old) were exposed to 50mM, 75mM, 100mM NaCl for 5 days. Ten-day-old seedlings were used for morphological characterization and metabolite analysis. Root and leaf length became shorter in high NaCl concentration compared to following NaCl treatment. For confirmation of salt accumulation, wheat roots were stained with $CoroNa^+$ Green AM, and fluoresce, and the image was taken by confocal microscopy. $Na^+$ ion accumulation rate was higher at 100mM compared to the untreated sample. Furthermore, to analyze metabolites in the wheat root, samples were extracted by $D_2O$ solvent, and extracted sample was analyzed by 1H NMR spectroscopy. Fourteen metabolites were identified in wheat roots using NMR spectroscopy. Methanol and ethanol were up-regulated, whereas formate, aspartate, aminobutyrate, acetate and valine were down-regulated under salinity stress on roots of wheat. Fumarate had no change, while glucose, betaine, choline, glutamate and lactate were unevenly affected during salinity stress.