• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.383-388
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• 2010

The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.49-59
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• 2009

Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.913-920
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• 2010

This study was conducted to improve the seed germination by low temperature and $GA_3$ in $Orostachys$ $japonicus$ A. Berger (Jirisan) and $O.$ $iwarenge$ (Mak.) Hara (Jejuyeonhwa), Korean native plants. Observation of the seeds using a stereo microscope showed that all seeds of the two species have wrinkled surface and oblong shape. Seed size ranged 0.77-1.00/0.25-0.37 mm (length/width), indicating that the seeds are minute seeds. When the seeds of two $Orostachsis$ species were sown into petri-dish and placed in a plant growth chamber of 10, 15, 20, or $25^{\circ}C$, 'Jirisan' showed seed germination below 20% at all temperatures and 'Jejuyeonhwa' 80% at only $10^{\circ}C$. Seed germination of 'Jirisan' increased up to 44% at $10^{\circ}C$ by low temperature ($4^{\circ}C$) storage for 10 days, but decreased again at storage for more than 20 days. The seeds of 'Jejuyeonhwa' showed a large increase in seed germination by low temperature for 20-30 days, which was 95% at $10^{\circ}C$, but low temperature for more than 40 days significantly decreased seed germination. Dipping treatment in GA3 solution of $50-400mg{\cdot}L^{-1}$ for different periods (3, 6, 12, and 24 hrs) remarkably improved germination rate and speed in both species, 80-100% in 'Jirisan' and 90-100% in 'Jejuyeonhwa' at all concentrations and dipping times used in this study.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.206-213
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• 2010

The aim of this study was to provide basic informations for restoring a habitat of Nannophy pygmaea Rambur. Environments and flora of the habitats were investigated in Youngdong, Sanbuk, and Nongam South Korea. The habitats were abandoned paddy fields with tree-unshaded space and with the water depths of about 2 - 10 cm all the year round. The water quality was recorded 5.44 - 7.33 in pH, 0.017 - 0.480 dS/m in EC, 1.34 - 4.94 mg/L in T-N and 0.06 - 0.46 mg/L in T-P. The pH and EC showed a wide range values, and T-N and T-P showed a high values comparatively. This result implies that a water quality does not important as the condition for a habitat of the species. A total of 86 vascular plant taxa belonging to 35 families, 60 genera, 67 species, 2 subspecies, 14 varieties and 3 forma were recognized in the habitats. Twenty two species (25.6%) overlapped among the habitats; Equisetum arvense, Salix koreensis, Persicaria thunbergii, Stellaria alsine var. undulata, Hypericum laxum, Kummerowia striata, Epilobium pyrricholophum, Oenanthe javanica, Mosla dianthera, Utricularia vulgaris var. japonica, Plantago asiatica, Eupatorium lindleyanum, Juncus diastrophanthus, J. effusus var. decipiens, J. papillosus, Aneilema keisak, Alopecurus aequalis, Arthraxon hispidus, Carex dickinsii, Cyperus sanguinolentus, Eleocharis acicularis for. longiseta and E. congesta. Biological type was determined to be HH-R5-D4-e(t) type; HH 39 taxa (45.3%), R5 42 taxa (48.8%), D4 59 taxa (68.6%) and e (or t) 23 taxa (26.7%).

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.65-72
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• 2005

Creeping bentgrass (Agrostis palustris Huds.) had been the problematic weed for Kentucky bluegrass (Poa pratensis L.) fairway since it shows light green color all year. Experiment was carried out to determine the best herbicides combination to control creeping bentgrass in Kentucky bluegrass. fairway without injury. To investigate the efficacy of herbicides, five post-emergence herbicides of asulam WG ($87.6\%$), imazaquin SL ($20\%$), fenoxaprop-P-ethyl EC ($7\%$), mecoprop SL ($50\%$), triclopyr-TEA SL ($30\%$) and one pre-emergence herbicide pendimethalin EC ($31.7\%$) treated on 21 Sept. and 10 Nov. 2003. Kentucky bluegrass visual quality evaluated 30 and 50 days after application for phytotoxic effects of the herbicides. As a result, asulam WG (0.2g/$m^{2}$) and imazaquin SL (0.3ml/$m^{2}$) showed approximately $90\%$ of control in creeping bentgrass, but visual quality of Kentucky bluegrass significantly decreased from 20 to 50DAT (day after treatment). However, creeping bentgrass was acceptably controlled(over $80\%$) by fenoxaprop-P-ethyl EC (0.4ml/$m^{2}$)+triclopyr-TEA SL(0.3 ml/$m^{2}$) applied twice on 21 Sept. and 1 Oct. 2003 without serious injury on Kentucky bluegrass. Therefore, it is suggested that an application of fenoxaprop-P-ethyl EC (0.4ml/ $m^{2}$)+triclopyr-TEA SL (0.3 ml/$m^{2}$) may be more effective to control creeping bentgrass in Kentucky bluegrass with the least phytotoxicity by herbicides.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.296-302
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• 1999

This experiment was conducted to study the effect of $CO_2$(0, 2, 500, 5, 000, 10, 000ppm) enrichment by enabling ventilation on micropropagation of multi-shoot and on the saponin contents in vitro in Korean ginseng (Panax ginseng C. A. Meyer). Embryo was cultured in Murashige and Skoog medium added 3mg/ l of Indolbutyric acid, Benzyladenin and Gibberellic acid $(GA_3)$, respectively. $CO_2$, enrichment had little effects on the number of adventitious buds and shoots originated from adventitious buds. The ratio of differentiated shoots to adventitious buds were about 50% in $CO_2$, enrichment treatment. The shoots originated from adventitious bud showed more rapid growth and had larger leaf area than the shoots originated from the leaf primordia did. The number of shoot primordia was the highest in 2, 500ppm of $CO_2$ enrichment treatment. On the contrary, 10,000ppm of $CO_2$, enrichment made smaller the number of shoot primordia and ratio of shoots to shoot primordia. The range of shoots differentiated was from shoot primordia were 15. 4 to 23. 9. The rate of dry weight of cultured shoots showed lowest (7. 5%) in control and highest (8. 59%) in 2, 500ppm of $CO_2$, enrichment. Rate of in vitro flower in control was 7.6% and that in 2500ppm of $CO_2$ was about twice (15.7-16.3%) as much as in control. Flower number per a embryo cultured was about 1.2-1.3. In the multi-shoots with callus enriched by 2, 500ppm of $CO_2$, the contents of crude saponin and ginsenosides in multi-shoots alone were higher than in multi-shoots with callus. The characteristics of ginsenosides in multi-shoots were especially the higher content of ginsenoside Rd, Re, and $Rg_1$.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.164-174
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• 1994

Temporal changes in growth performances, chlorophyll contents, and tissue water relations for determining their physiological responses of five economic tree species subjected to chronic water and nutrition stresses were investigated with containerized seedlings grown in different soil moisture regimes and nutrition levels. Seedlings of Quercus acutissima, Q. variabilis, Q. mongolica, Q. serrata, and Fraxinus rhynchophylla were propagated in plastic pots(I.D. $16cm{\times}Depth$ 16cm) for the experiments. The seedlings were subjected to two soil moisture regimes of dry and wet soils and two nutrition levels of fertilization with N+P+K and no fertilization through the growing season from May to September in a green house. For the purpose of analyzing their responses to the environmental stresses, seedling heights and root collar diameters, chlorophyll contents, and P-V curve parameters of the seedlings were measured in May, July, and September. The environmental stresses coming from moisture and nutrient deficits affected the growth performances of seedlings variously among species and among different growing periods, as well as between height and basal diameter growth of seedlings. The growth performances of Q. acutissima were influenced sensitively on the stresses, but those of Q. mongolica less influenced in comparison with other species. Chlorophyll contents were generally higher in Quercus spp. than F. rhynchophylla through the growing season. The chlorophyll contents changed by species and by treatment through the season within ranges of 0.14~1.96 mg/g dry wt. of chlorophyll a and within 0.16~1.79mg/g dry wt. of chlorophyll b, respectively. But the contents seemed to be decreased gradually through the chronic environmental stresses and leaf senescence. The osmotic potential at full turgor(${\Psi}{{\pi}o}$) and turgor loss point(${\Psi}{\pi}p$) had temporarily declined up to 3 to 5bars from -7.0~-12.4bars in May to -10.2~-17.5bars in September and up to 5 to 6bars from -7.6~-14.2bars in May to -12.9~-20.4bars in September, respectively, with some exceptions. The values of ${\Psi}{\pi}p$ were generally high in F. rhynchophylla in May and July, but high in Q. serrata in September. Relative water contents at turgor loss point(RWCp) were generally high in F. rhynchophylla, but the temporal changes of RWCp were quite and frequently different among species and among treatment.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.151-158
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• 1993

This experiment was conducted in order to understand the intra-and the inter-competition of arrowhead, Sagittaria trifolia L., under the conditions of arrowhead monoculture and rice-mixed culture, respectively. In arrowhead monoculture, the infra-specific competition in both shoot length and floral axis number began at 10 plants per $0.5m^2$ and that in leaf number, leaf length, dry shoot weight and formated tuber number did at 5 plants per $0.5m^2$. In the inter-specific competition according to arrowhead density in the constant rice-mixed culture, the plant height and the tiller number of rice decreased at 15 and 5 plants of arrowhead per $0.5m^2$, respectively. The dry top weight and the formated tuber number of arrowhead decreased with increase of arrowhead density. In the inter-competition according to rice plant density in the constant arrowhead-mixed stands, the dry matter weight and the produced tuber number of arrowhead decreased with increase of rice plant density and the plant height and the tiller number of rice also did with that. In the different transplantation time of rice, the growth in arrowhead became less in order of late transplantation>standard one>early one and the plant height and the tiller number of rice became more in order of that by comparing the percentage of growth under the mixed culture to that under the arrowhead monoculture.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.170-176
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• 2008

This study was carried out to improve density of arbuscular mycorrhizal fungi (AMF) propagule and physiochemical properties of soil by planting crops at the preplanning field for ginseng cultivation. Winter crops, such as barley and rye and summer crops, such as sudangrass and soybean were cultivated in combination to improve AMF propagation and soil aggregation at the fields. Yield of harvested crops by plating with winter or/and summer crops was $3,045kg\;10a^{-1}$ of the only rye cultivation, $2,757kg\;10a^{-1}$ of sudangrass cultivation in combination with rye growing (rye/sudangrass) and $1,628kg\;10a^{-1}$ of soybean cultivation in combination with barley growing (barley/soybean), respectively. Soil aggregation rate was improved by cultivation with barley (45.7%) and with rye/sudangrass (45.1%), respectively. The density of AMF spores in soil was increased slowly by cultivating with winter crops. In summer crops cultivation system, density of AMF spores at sudangrass cultivated field was $64.0spores\;g^{-1}$ dried soil and it was higher than that at soybean cultivated field. External hyphae length (EHL) was $1.5{\sim}2.0m\;g^{-1}$ air-dried soil at winter crops cultivated field. However, in summer crops cultivation systems, EHL was $2.6{\sim}2.9m\;g^{-1}$ airdried soil at sudangrass cultivated field and was $1.7{\sim}2.2m\;g^{-1}$ air-dried soil at soybean cultivated filed, showing these were higher than those in non-cultivated field (control). Glomalin content of soil cultivated with crops was higher than that of control soil. Especially, the highest glomalin content was shown to $1.7m\;g^{-1}$ air-dried soil in the barley/soybean cultivation systems. These results suggested that the most effective soil management to improve AMF propagule density and soil physical properties by planting crops system was cultivating sudangrass followed by barley at the preplanning fields for ginseng cultivation.