• Horticultural Science & Technology
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• v.29 no.5
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• pp.474-481
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• 2011

Potato late blight caused by the fungus Phytophthora infestans is one of the most vital diseases damaging the potato plant. It is for this reason that breeding potato cultivars resistant to late blight is now becoming a major concern around the world. The B3C1 clones has been introduced by the Highland Agriculture Research Center, RDA. The clones which came from International Potato Center in 2005 have a durable resistance to late blight. The clones were bred under a short-day condition in Peru. However, there was still no report on the adaptability of these clones to the long-day condition in Korea. Therefore, this study was conducted to evaluate the late blight resistance and major agronomic characteristics of B3C1 clones under Korea's long-day condition. This study was also done to generate genetic resources for developing new varieties resistant to late blight. In this study it was found out that in naturally infested field with P. infestans, AUDPC (area under disease progress curve) values of all B3C1 clones were significantly lower than those of the control varieties, 'Superior', 'Atlantic', and 'Haryeong'. It was found out that B3C1 clones had a high level of resistance to late blight and that they could be used as genetic resources to breed potato varieties with late blight resistance. However, several undesirable characteristics such as extremely late maturity, excessive growth of stems and stolons, and production of tubers that cannot easily be removed from the stolons were also observed. Among the twenty B3C1 clones, two clones, LB-8 (CIP393077.159) and LB-11 (CIP393371.159), were selected for cultivating at the highland area of Korea. Two B3C1 clones were crossed with Korean breeding lines and clonal selection for the progenies is still in progress.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.87-92
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• 2015

This experiment was conducted to evaluate the effect of seeding methods and application levels of nitrogen fertilizer on the yield and forage quality of whole crop rice (WCR). The WCR variety "Namil" was directly seeded on April 25 and transplanted on May 25. Five levels of nitrogen fertilizer were applied (90, 110, 140, 170 and 200 kg/ha). There were no significant differences (p<0.05) of the emergence date, heading date and disease resistance based on the nitrogen fertilizer rates; however, the WCR became dark at higher nitrogen fertilizer rates. The plant height increased at higher nitrogen fertilizer rates and the tiller number showed the same trend. In contrast to a direct seeding method, transplanting increased the tiller number. The dry matter (DM) content did not show a certain tendency based on nitrogen fertilizer rates, while the fresh and dry matter yields increased with incremental changes of the nitrogen fertilizer rates (p<0.01), and the transplant method increased the yield size. In yield analysis, the plot direct-seeded with 140 kg N/ha and the transplanting with 170kg N/ha showed the highest yields. The crude protein (CP) content increased with higher nitrogen fertilizer rate, but there was no significant differences between transplant and direct-seeding methods. The content of ADF (acid detergent fiber) and NDF (neutral detergent fiber) increased with higher nitrogen fertilizer rate, but total digestible nutrient (TDN) content decreased with increased nitrogen levels. Although high nitrogen applications increased the fresh and DM yields, the 140 kg/ha nitrogen fertilizer level is recommended as the proper nitrogen fertilizer level, considering both yield and the environments.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.85-92
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• 2006

Fungicides including keroxym-methyl (strobilurin fungicide), fenarimol and trifulmizole (DMI, boscalid (anilide) and metrafenone (benzophenone) were evaluated for preventive and curative efficacies against powdery mildew on oriental melon. The fungicides were applied preventatively at 7 days, 3 days and 3 hours before inoculation. Curative applications were made by applying fungicides three times at the interval of one week when infected leaves by powdery mildew were about 16% or 30%. Then preventative and curative efficacies were evaluated one week after inoculation and final application, respectively. Boscalid and metrafenone showed preventive efficacies of 74.3 and 68.3% against powdery mildew development respectively, when treated at 7 days before inoculation. They showed 89.4 and 87.2% efficacies when treated at 3 days before iniculation and 98.5 and 93.2% at 3 hours before inoculation respectively. However, there were no preventive efficacies in kresoxym-methyl, triflumizole and femarimol (DMI fungicides) when trebled at both 7 and 3 days before inoculation. At the preventive treatment 3 hours before inoculation, they indicated 59.0, 42.5, and 37.2% efficacies, respectively. When leaves were infected about 30% by powdery mildew, curative application of boscalid and metrafenone showed 85.9 and 74.0% of efficacies, respectively. Curative efficacies of kresoxym-methyl, tiflumizole and fernarimol were 5.5, 23.0 and 46.7% respectively. When leaves were infected about 16%, curative application of boscalid and metrafenone showed 100 and 97.5% of efficacies, respectively. However, the triflumizole and fernarimol showed relatively low curative efficacies of 30.8 and 51.6%, respectively. Microscopic observation of mycelial growth and conidia formation after detection of powdery mildew disease indicated lysis of mycelium and these lysis suppression of conidia formation showed tendency in accordance with curative efficacies of fungicides.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.250-256
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• 2002

The objective was to know if chinese cabbage growers in Gangwon alpine farmland control agricultural pests including weeds effectively and use pesticide properly. Examiners visited 185 farmers at Taebaek, Pyongchang, and Jeongseon and surveyed 33 questions on pest control methods pesticide use. Chinese cabbage farmers have noxious plant diseases such as clubroot, bacterial soft rot, downy mildew, anthracnose, and mosaic disease, and also noxious insects such as diamondback moth, aphid, beet armyworm, common cabbage worm, and Japanese native slug. In addition, farmers have noxious weeds such as common chickweed, marsh pepper, hairy crabgrass, common purslane, and horseweed. To control diseases and insects, 51.3% of farmers used many chemical agents, while 20.7% of farmers used chemical agents with too much emphasis on paraquat and glyphosate to control weeds: 87.2% of the answered farmers have a preference of the both non-selective herbicides. Farmers in the survey area selected pesticides on the basis of their own experience and sales managers' recommendation (84.2%) which results in the use of inappropriate pesticides such diniconazole. Many farmers have experienced phytotoxicities (46.7%) and pesticide poisoning (51.2%). We conclude that a systematic educational program for the proper selection and use of pesticides should be conducted for chinese cabbage growers in Gangwon alpine farmland.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.159-166
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• 2008

An ideal anti-bacterial medication for oral infection requires selective effect on pathogens causing dental caries and periodontal disease but not on normal flora. In addition, it should be less toxic for human and even for environment. This study was to seek such a natural anti-bacterial medication and thus anti-bacterial effect of Hamamelis virginiana was evaluated. Many recent researches on the anti-bacterial effect of natural plant extract and essential oil have reported that natural products can be used as medication for prevention and restrainment of dental caries, halitosis and periodontitis. It has been also reported that Hamamelis virginiana has anti-bacterial effect on Porphyromonas gingivalis, Fusobacterium nucleatum, Capnocytophaga gingivalis, Veilonella parvula, Eikenella corrodens, Peprostreptococcus micros, and Actinomyces odontolyticus. This study evaluated anti-bacterial effect of Hamamelis virginiana on Streptoccoccus mutans, Haemophylus actinomycetemcomitans, and Klebsiella pneumoniae to expand its anti-bacterial effect on other important oral pathogens and eventually to develop its oral care products or apply to clinical purpose. In this study, anti-bacterial tests for antibiotic disk susceptibility, minimal inhibitory concentration and minimal bactericidal concentration were performed to evaluate anti-bacterial effect of Hamamelis virginiana against Streptoccoccus mutans, Haemophylus actinomycetemcomitans, and Klebsiella pneumoniae. The results showed that Hamamelis virginiana has anti-bacterial effect on all pathogen strains tested in this study and furthermore Hamamelis virginiana possesses bactericidal effect other than bacteriostatic effect on Streptoccoccus mutans, Haemophylus actinomycetemcomitans, Klebsiella pneumoniae. This study indicates that a natural anti-bacterial medication for oral diseases can be developed using Hamamelis virginiana.

• Journal of The Korean Association For Science Education
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• v.36 no.2
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• pp.203-219
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• 2016

The purpose of this paper was analyzing the contents of life science area in elementary science textbooks according to Korean science curricula change to get suggestions for the advancement of science curriculum. The framework of content analysis was developed by revising TIMSS 2015 life science evaluation framework. The results of this research were as follows: 'The differences of living things and non-living things appearing in the first grade mostly were not included in the 1st, the 6th and the 2009 revised curricula. Contents emphasizing rural life were appeared from 'Teaching themes period' to the 2nd curriculum period, disappeared from the 3rd curriculum period until the 2009 revised curriculum. Contagious disease was emphasized in all elementary grades in the 1st curriculum period, which reflected a social phenomena emphasizing health and hygiene after the Korean War. Mostly fungus was included until the 7th curriculum period and bacteria and virus were added from the 2007 revised curriculum period. The way of improving health was emphasized continuously.' The differences of living things and non-living things should be included in elementary science curriculum for the correct 'life' concept formation of elementary students. 'Strategies for helping the living of descendants' and 'the heredity of animal and plant' which were appeared in the lower grades, should be included at the higher grades with greater depth. The incoming elementary science textbooks also need to include science contents about evolution in greater depth, along with human health.

• Journal of Forest and Environmental Science
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• v.19 no.1
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• pp.85-98
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• 2003

The articles, published in the Journal of Korean Forestry from Number 1(1962) to Number 6, Volume 91(2002), were surveyed and investigated for the research trend analysis about resource-plants for special use or purpose, i. e., edible plants, medicinal plants, feed resource, landscape plants, fiber plants, industrial usuage, and bee plants. If the purpose or subject matter of the research was construction or furniture timber production, mushrooms and/or pulp and paper, such research was not included in this study. These articles were classified again depending on the content of research into 14 categories: habitat environment, ecology, physiology, propagation, silviculture (tending and culture), genetics and breeding, identification, insect and disease control, animal-related research, component analysis, vegetation survey, biotechnology, management, and review. Among the total 1.434 articles published, 396 ones (27.6%) were related with plants for special use or purpose. Vegetation survey was 60 (15.2%): physiology 56(14.1%) : genetics and breeding 56(14.1%): propagation 53(13.4%): and ecology 37(9.3%). Siviculture research field included 11 articles (2.8%), which indicates that the management of resource-plants is so far from economic income as seen in the low number of management research filed articles, i. e., only 6 reports (1.5%) Korean white pine was most popular for research and included 42 articles: Robinia pseudoacacia 23: Castanea crenata 14: and ginkgo tree 14. Research related with these species had focused mainly on propagation, physiology, genetics and breeding, ecology and pest control. Based on this survey and analysis, the followings are suggested: 1. More research is required on forest herbaceous plants. 2. Cooperative research work with other industrial and/or scientific area is recommendable for commercialization including medicine, cosmetics, and food etc. 3. Research on resource-plant conservation, which includes biology, social education and policy, should be supported for next generation. 4. Mutual correspondence and information exchange about the research results between researchers and institutes is more necessary than now.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.375-380
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• 2014

The sweetpotato whitefly (SPW), Bemisia tabaci Gennadius, is a major pest in tomato greenhouses on Jeju Island because they transmit viral diseases. To develop practical sampling methods for adult SPWs, yellow-color sticky traps were used in commercial tomato greenhouses throughout the western part of Jeju Island in 2011 and 2012. On the basis of the size and growing conditions in the tomato greenhouses, 20 to 30 traps were installed in each greenhouse for developing a sampling plan. Adult SPWs were more attracted to horizontal traps placed 60 cm above the ground than to vertical trap placed 10 cm above the plant canopy. The spatial patterns of the adult SPWs were evaluated using Taylor's power law (TPL) and Iwao's patchiness regression (IPR). The results showed that adult SPWs were aggregated in each surveyed greenhouse. In this study, TPL showed better performance because of the coefficient of determination ($r^2$). On the basis of the fixed-precision level sampling plan using TPL parameters, more traps were required for higher precision in lower SPW densities per trap. A sequential sampling stop line was constructed using TPL parameters. If the treatment threshold was greater than 10 maximum adult SPWs on a trap, the required traps numbered 15 at a fixed-precision level of 0.25. In estimating the mean density per trap, the proportion of traps with two or more adult SPWs was more efficient than whole counting: ${\ln}(m)=1.19+0.90{\ln}(-{\ln}(1-p_T))$. The results of this study could be used to prevent the dissemination of SPW as a viral disease vector by using accurate control decision in SPW management programs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.814-821
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• 2014

As a natural plant ingredients, glasswort (Salicornia herbacea L.) contains various physiological activities, mainly anti-oxidative and anti-diabetic activities. However, only a few studies have been carried out on its anti-adipogenic effect. This study investigated the anti-obesity effects of Salicornia herbacea L. on 3T3-L1 adipocytes. As adipogenesis of preadipocytes to adipocytes involves proliferation and differentiation of cells, we treated three concentrations (125, 250, and $500{\mu}g/mL$) of Salicornia herbacea L. water extracts (SLW) in both pre-processing and post-processing stages. When 3T3-L1 adipocytes were differentiated and dyed with Oil Red O, adipocytes size and the value of relative Oil Red O staining were reduced by all concentrations of SLW in post-processing stage. Following adipogenic differentiation, the concentration of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in the cell supernatant significantly increased upon treatment with $125{\mu}g/mL$ of SLW and further rose at concentrations of 250 and $500{\mu}g/mL$ during post-processing stage. There was no significant difference in glycerol production upon SLW treatment. Leptin production significantly decreased at all SLW concentrations during post-processing stage, whereas peroxisome proliferator activated receptor-${\gamma}$ (PPAR-${\gamma}$) and adiponectin secretions were significantly enhanced. Overall results showed that SLW might have an anti-adipogenic effect via enhancement of TNF-${\alpha}$ production, which causes dedifferentiation and inhibits lipid accumulations in adipocyte. Furthermore, SLW might prevent diabetes and cardiovascular disease, as it reduces leptin secretion and enhances production of both PPAR-${\gamma}$ and adiponectin. However, further research is needed to elucidate the exact mechanism and bioactive compounds of glasswort.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.311-319
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• 2013

In an effort to characterize the physicochemical properties and microbial risks associated with the soy sauce jangachi (Korean traditional pickle), 15 different home-made products, which were prepared from medicinal plants and wild edible vegetables, from head-families of Andong, Kyungsangbuk-do Province in Korea, and 6 different commercial products sold at supermarket, were investigated. The average pH of the mature soaking solutions and plants soaked in the 21 jangachi were $3.99{\pm}0.38$ and $3.51{\pm}0.41$, and the average acidity of the mature soaking solutions and soaked plants were $1.59{\pm}0.54$ and $1.65{\pm}0.76$, respectively. The average brix of the mature soaking solutions and plants soaked were $27.67{\pm}8.38$ and $25.61{\pm}6.60$, respectively. In salinity, which is a major factor in jangachi industry production, the average salinity of the mature soaking solutions and soaked plants were $7.55{\pm}3.26$ and $5.75{\pm}2.23$, respectively. In particular, the hot-peppers, eusuri, du-rup, kaet-ip, kuji-ppong, myeng-i and sancho jangachi were amongst the home-made products, and the salinity was above 8.8%, which was 2 folds-higher than that of the commercial sterilized products, and 1/3-lower than commercial non-sterilized products. The color difference and turbidity of jangachi were dependent on the plant parts used. In microbial risk assessment, the microorganisms related with food-borne disease, such as Escherichia coli, Salmonella sp, and Shigella sp., were not detected. After some time, total cell count analysis revealed that the commercial products sold at supermarkets were more vulnerable than the home-made products.