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        검색결과 183

        81.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        Background: The application of crop rotation systems may reduce the occurrence of soil-borne diseases by releasing allelochemicals and by subsequent microbial decomposition. Methods and Results: For reduction of ginseng root rot by the crop rotation system, after harvesting 6-year-old ginseng, fresh ginseng was grown along with continuous cultivation of sweet potato, peanut, and bellflower. Growth of 2-year-old ginseng was significantly inhibited in the continuous cultivation than in the first cultivation. Sweet potato, peanut and bellflower cultivations assisted in obtaining normal yields of ginseng in the first year after the harvest of 6-year-old ginseng. Salt concentration, potassium and sodium contents were gradually decreased, and, organic matter was gradually increased through cirp rotation. Phosphate, calcium and magnesium contents were not altered. The density of the root rot fungus was gradually decreased by the increase in crop rotation; however it was decreased distinctly in the first year compared to the second and third year. The severity of root rot disease tended to decrease gradually by the increase of crop rotation. Conclusions: Short-term crop rotation for three years promoted the growth of ginseng, however root rot infection was not inhibited significantly, although it was somewhat effective in lowering the density of the root rot pathogen.
        82.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to extract climate factors affecting sweet persimmon yield by growth period and estimate the rate of future sweet persimmon yield using data of production and cultivation area of sweet persimmon and climate data for 1998-2015. During the analysis period, the cultivation area of sweet persimmon in Gyeongnam has been consistently decreasing, but sweet persimmon yield has increased. Climate factors that have statistically significant effects on sweet persimmon yield are mean temperature, maximum temperature, precipitation, precipitation days, and sunshine hours. The sweet persimmon yield is a statistically positively correlated with temperature and sunshine hours and negatively correlated with precipitation during the flowering period (April to May). The sweet persimmon yield is statistically positively correlated with precipitation in the growing period (June to August) and negatively correlated with temperature in maturity period (September to November). Future sweet persimmon yield is estimated to have a steadily decreasing rate of change in future climate change scenarios, RCP4.5 and RCP8.5.
        83.
        2017.05 서비스 종료(열람 제한)
        Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). Methods and Results : Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on virulence. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and culture characteristics. As results of investigated culture characteristics, optimal temperature for mycelial growth of isolates were 20℃, and colony pattern and color were slightly different on PDA. Isolates of I. radicicola were analyzed for their genetic relatedness based on several genes and microsatellite region. I. radicicola group was divided into two small groups. Conclusion : Therefore, we were able to confirm pathogenicity and genetic difference between the isolates in each of the groups of the pathogen. Among these isolates, 21.5% were classified as highly virulent and 78.5% were weakly virulent. *(Corresponding
        84.
        2017.05 서비스 종료(열람 제한)
        Background : The fungus Cylindrocarpon destructans (Zins) Scholten is the cause of root rot in many ginseng production areas. Root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. Methods and Results : Five kinds of rotation crops, sudan grass soybean peanut sweet potato, perilla were grown for one year in ginseng garden harvested 6-year-old ginseng. The ratio of gram-negative bacteria, fungi, bacteria, total microbial biomass, aerobic/anaerobic microbes were increased by rotational crop cultivation, while the ratio of actinomycetes and the ratio of saturated to unsaturated fatty acids were decreased. The increase in the fungal density or the increase in the proportion of fungi to the bacteria tended to increase the incidence of root rot, but there was no significant difference. The yield of ginseng root showed a highly significant negative correlation with actinomycetes. The correlation between the soil chemical properties and the incidence of root rot was analyzed by cultivating 23 kinds of green manure crops for one year in field where cultivated ginseng continuously. The survival rate of ginseng showed a highly significant positive correlation with soil acidity and a highly significant negative correlation with nitrate nitrogen, and a significant negative correlation with soil salt concentration. Conclusion : Rotation crops improved soil microbial communities, lowered the rate of fungi and increased the proportion of bacteria, the survival rate of ginseng was significantly correlated with soil acidity, nitrate nitrogen and soil salinity.
        85.
        2017.05 서비스 종료(열람 제한)
        Background: Some plants have harmful effects on fungi and bacteria as well as plants. Incorporating into soil as green manures are effective in reducing population densities of soil pathogens. Methods and Results: Twenty-three species of green manure crops were cultivated after the harvest of 6-year-old ginseng and then incorporated green manure into the soil at the flowering stage. The following year, the root rot ratio of 2-year-old ginseng and soil chemical properties were investigated. Sorghum sudanense, Helianthus annuus, and Helianthus tuberosus were relatively high in dry matter production. Without incorporating green manure into soil, NO3, EC (electric conductivity) and K were decreased by 95%, 79% and 65%, respectively. When green manure was incorporated to soil, P2O5 and NO3, were reduced by 41% and 25%, respectively. The survived root ratio of 2-year-old ginseng were significantly increased by 56.2%, 47.5%, and 47.3% in Sorghum sudanense, Ricinus communis and Helianthus tuberosus, respectively, In addition, there was a significant increase in Secale cereale, Chrysanthemum morifolium, Atractylodes macrocephala, and Smallanthus sonchifolius. The survived root ratio of ginseng showed a significant positive correlation with soil pH and a negative correlation with NO3, and EC. Conclusion: Cultivation of Chrysanthemum family mainly using rhizome and root as green manure was effective for root rot disease of ginseng.
        86.
        2017.02 KCI 등재 서비스 종료(열람 제한)
        Background: Some plants have harmful effects on fungi and bacteria as well as other plants. Incorporating such plant into soil as green manure is effective in reducing population densities of soil pathogens. Methods and Results: Twenty-three species of green manure crops were cultivated after the harvest of 6-year-old ginseng and then incorporated into the soil at the flowering stage. The following year, the root rot ratio of 2-year-old ginseng and soil chemical properties were investigated. In the absence of green manure addition, the NO3 content, electric conductivity (EC), and K content decreased by 95%, 79% and 65%, respectively. In the presence of green manure addition, P2O5 and NO3 contents reduced by 41% and 25%, respectively. The “survived root ratio” of 2-year-old ginseng significantly increased by 56.2%, 47.5%, and 47.3%, in the Sorghum sudanense, Ricinus communis and Helianthus tuberosus treatment, respectively. In addition, there was a significant increase in the “survived root ratio” in the Secale cereale, Chrysanthemum morifolium, Atractylodes macrocephala, and Smallanthus sonchifolius treatments. The “survived root ratio” of ginseng showed a significant positive correlation with the soil pH and a negative correlation with the NO3 contents, and EC. Conclusions: Cultivation of plant form the Chrysanthemum family as green manure, using mainly the rhizomes was effective for the control of root rot disease of ginseng.
        87.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        This study was aimed to analyse spatial patterns of the monthly amounts of damage by heavy snowfall in Korea using damage data of disaster yearbook at all cities and guns(country level) in Korea during 1980-2014. Most damages by heavy snowfall happened in January, followed by March, December, February, and November. The spatial distribution of snowfall disaster areas by themselves represented a strong spatial positive autocorrelation. The local spatial autocorrelation is drawn by the LISA cluster map. The distribution of snow disaster area is not independent of a spatial context within geographic limits, forming a spatial cluster. We examined the synoptic scale situation in monthly extreme events of damage by heavy snowfall based on composite analysis. The result shows the snowfall disaster is characterized by low pressure in January. The snowfall disaster in February is characterized by easterly wind. The snowfall disaster in March is mainly due to low pressure. Westerly wind with west-high and east-low pressure system pattern is predominant in December.
        88.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Background: Cylindrocarpon destructans (Zins) Scholten is an important pathogenic fungus that causes ginseng root rot in many ginseng growing areas in China. Although C. destructans have been studied worldwide, research on its chemotaxis towards ginseng (Panax ginseng C. A. Meyer) root exudates in the rhizosphere remains limited.Methods and Results: In this study, we collected ginseng root exudates with three different polarities from three-year-old ginseng roots, and performed chemotaxis and spore germination assays to investigate the ability of these exudates to induce the response in C. destructans. The results showed that, compared with other conditions, when C. destructans cultivated at 20°C and a pH of 6 exhibited a strong positive chemotactic response toward 2 ㎎/ℓ aqueous phase, 20 ㎎/ℓ butanol phase, and 0.2 ㎎/ℓ petroleum ether from ginseng root exudates, the chemotactic moving indexes were 0.1581, 0.1638 and 0.1441, respectively. In addition, the spore germination rate with optimal chemotactic parameters were 48%, 53%, and 41% in the aqueous phase, butanol phase and petroleum ether groups, respectiviely, which were significantly higher than that in the control group (23%) (p < 0.05). The mycelial growth rate with optimal chemotactic parameters increased with culture time, and the maximum growth rates in the aqueous phase, butanol phase and petroleum ether groups were 0.425, 0.406 and 0.364 respectively, on the 4th day. The optimal chemotactic parameters were 39.73 ㎎/50 ㎎/ℓ , 48.93 ㎎/50 ㎎/ℓ , and 31.43 ㎎/50 ㎎/ℓ , in aqueous phase, butanol phase and petroleum ether respectively, from ginseng root exudates, compared with 5.5 ㎎/50 ㎎/ℓ , in the control group.Conclusions: The present study revealed that certain ginseng root exudates containing chemical attractants act as nutritional sources or signals for C. destructans and support its colonization of ginseng roots.
        89.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng widely cultivated as a major medicinal herb in Korea, is economically important crop for farmer. Ginseng root disease caused by soil borne pathogens is main factors restricting the quantity and quality of ginseng. The disease can result in harvest loss of up to 20~70% and limits the replanting of ginseng under same field for long time. The traditional control method of agrochemical use is not recommend to control soil borne disease because of difficulty in use and unstable effect. The objective of this study was to evaluate the efficacy of several antagonistic microbes for developing biological control method of ginseng root rot. Methods and Results : To select biocontrol agents against ginseng soil borne disease, several bacteria were isolated from ginseng root and rhizosphere soil evaluated in vitro screening of antifungal bacterial against ginseng root pathogens. Two antagonistic bacteria, ES17 and CJ4, showed the strongest inhibition effect against ginseng root pathogen. In the pot experiment under greenhouse conditions, ginseng seedling dipped in bacterial suspension at inoculum density of 106 cfu/ml for 1 hour were planted in pot containing inoculum. Control effect was examined depend on disease severity index at 30 days after inoculation. Ginseng root treated with CJ4 and ES17 isolate reduced root rot disease development on the ginseng root with degrees of control efficacy of 85% and 70%, respectively. Conclusion : Two biocontrol agent, Burkholderia ambifaria CJ4 and Paenibacillus strain ES17, had strong antifungal efficacy against ginseng soil borne pathogens. These results obtained from in vitro test and pot experiment suggest the potential applicability of the biocontrol agent to control ginseng root rot caused by various soil borne pathogens.
        90.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). To monitor contamination with C. destructans in ginseng harvested in 2015 were sampled from 57 different growing fields. The spore number of C. destructans was quantified by use of a specific primers and selective media (radicicol) in soils of ginseng fields. Methods and Results : The ginseng samples were surface-sterilized and placed on potato dextrose agar plates for 7 day incubation at 20℃. Emerging fungal colonies were counted primarily based on colony and conidia morphology. Further species level identification was confirmed by ITS rDNA sequencing. For quantification of the soil-borne C. destructans, the genomic DNA was extracted from the soil using a NucleoSpin soil kit (MN, Germany). Density of C. destructans was determined by species specific real time PCR (qPCR). The qPCR was completed by running a melting curve analysis. Conclusion : The C. destructans associated with root rot disease of ginseng were detected in more than 60% in pyeongtaek-1, pochenon-1, jecheon-1, chungju-1 and jinan-4. As results of the study, the correlation between pathogen density and identification clearly clarified in the soil.
        91.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng root rot caused by soil-borne pathogens, Cylindrocarpon destructans and Fusarium solani, is a major factors of replanting failure in ginseng cultivation. Some of the phenolic compounds detected in the soil of commercially cultivated American ginseng could inhibit the seed germination and seedling growth of American ginseng. Our study is to investigate the causes of replanting failure of ginseng by overhead flooding treatment and soil incorporation of ginseng fine root in soil infected with root rot pathogens. Methods and Results : To make soil occurring continuous cropping injury, 2-year-old ginseng infected with Cylindrocarpon destructans replanted in soil cultivated ginseng for 5 years. Treatment are as follows: 1) control, 2) water of 2ℓ was irrigate infected soil of 20ℓ, 3) ginseng fine root of 20g was mixed with infected soil of 20ℓ. Soil pH was increased, while other inorganic components were significantly reduced by overhead flooding treatment. Soil incorporation of ginseng fine root decreased soil pH, but increased EC, NO3, P2O5 and K, meanwhile, did not affected changes in organic matter, calcium, magnesium, sodium. Irrigation treatment in soil occurring replanted failure promoted distinctly above-ground growth of ginseng, and inhibited the occurrence of root rot because inorganic nutrient like NO3, P2O5 and K were decreased to optimal levels, and the density of soil pathogens could be reduced. Growth of ginseng was not inhibited, while root rot was promoted by soil incorporation of ginseng fine root. Conclusion : Irrigation treatment was effective in promoting the growth of ginseng and inhibited root rot distinctly. Ginseng fine root remaining in the soil after ginseng harvest did not affect the above-ground growth of ginseng, while promoted the occurrence of root rot.
        92.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        High temporal resolution precipitation data can provide information about rainfall intensity, and can better reveal the essential physical process of precipitation intensity than daily totals do. Using hourly precipitation data at 14 stations during 1961-2014, the changes in the characteristics of summer precipitation in South Korea analysed. Although the precipitation amount in summer has increased at all stations, hourly precipitation in summer shows different directions and magnitudes of changes at each station in South Korea. Results showed that the change pattern of hourly precipitation is mostly attributed to change in the frequency of hourly precipitation of 10mm or more.
        93.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, NO3, and P2O5 content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.
        94.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Three Supreme Court’s rulings are reviewed in this paper. They are all about the similar cases. Someone asked the other person to withdraw a specific sum of money from his account, but the latter(the delegated person) withdrew an excess and took it. What sort of crime should be assigned to him? The ruling A presents the view of fraud by electronic instrument. It says that defendant took illegal gain through inputting unauthorized data into ATM. Another judgement, the ruling B, sets forth the different view. It declares the breach of trust, saying that defendant violated his duty. The final judgement, the ruling C, also deals with the case alike. However it supports the decision of the lower court to give defendant the embezzlement verdict. To sum up, there are contradicted rulings on the same case! What solution could be made to handle such confusion. It is the task of this paper. The conclusion is the crime of embezzlement, it means that the ruling C is appropriate. This paper presents its grounds and arguments and hopes for readjusting The Supreme Court’s ruling forward.
        95.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Extreme temperature has direct and indirect effects on Human Health, and usually influences negatively. This study analyzes the correlation between extreme temperature and excess mortality caused by cardiovascular disease in Seoul. Excess mortality correlates with daily maximum temperature, especially daily excess fatality over two standard deviations, has a strong positive correlation. On the other hand, daily minimum temperature is not significantly related with excess death. Recently, significance of the correlation coefficient of high temperature in August decreases because of the heat wave preparation.
        96.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        In this study, spatio-temporal distribution was analyzed with the number of days for summer heat wave and winter cold wave defined as three or more consecutive +5% quantile days and -5% quantile days, respectively, by using daily maximum temperature in summer and daily minimum temperature in winter during 1973-2015. Although monthly heat wave occurrence has been only concentrated in July and August during the 1970s and 1980s, it had further extended into June and September since the 2000s. Monthly cold spell occurrence has been distinguished by increasing occurrence ratio in the month of December since the 2000s. The occurrences of heat waves were classified into either strong or weak cluster depending on intensity and magnitude over the entire region of South Korea rather than in specific areas. On the other hand, the occurrences of cold spell were classified by intensity of cold spell and spatial distribution of dominant cold spell areas over South Korea.
        97.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        Anomaly high temperature caused by constant global warming has a direct impact on the thawing of the Arctic and Antarctic Ocean. This suggests new opportunities for alternative Northern Sea Routes that were not an option before, due to the economic feasibility. The current study reviews the existing research work on this issue over the world. Results indicate positive possibility of Northern Sea Routes (NSR) from the decrease of distance. But if the ice-breaking, the toll of NSR and the potential environmental risk are still high, the NSR has not economic profits compared with the existing routes (via Suez, via Panama). This study suggests the research direction for the economic investigation of the Northern Sea Routes.
        98.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study was aimed to investigate the spatial distributions and temporal changes of disaster areas due to heavy snowfall at all cities and guns (country level) in Korea during 1979-2014. The number of days of damage caused by heavy snowfall has increased, and amounts of damage also increased. However, the number of casualties by the heavy snowfall damage has decreased in the deaths and missing. Although the damage by heavy snowfall was concentrated in Gangwon Yeongdong region during 1980s, the damage had extended to the eastern coast of Gyeongbuk region, Chungcheong region, and the western coast of Jeolla region in 1990s. In 2000s, the damage was largely concentrated in Gyeonggi region, Chungcheong region and the southern part of western coastal area while the damage in the surrounding regions of the Taebaek Mountains were dominant during the early 2010s. The spatial and temporal patterns of the damage caused by heavy snowfall have changed over the study period with the decadal variations.
        99.
        2016.05 서비스 종료(열람 제한)
        Background : Cylindrocarpon root rot, caused by Cylindrocarpon destructans and Fusarium solani, is a major disease which lead to replanting failure in ginseng garden. Chlamydospores of C. destructans, generated by poor environmental condition, can survived more than ten years in soil without host plant, ginseng. Density of soil pathogens gradually decreased as the progress of time since ginseng was harvested. Methods and Results : Soil chemical properties was analyzed from soil samples of 43 regions in farmer’s ginseng garden to study the variation of content and the correlation among inorganic contents. Soil samples of 24 regions was also analyzed to study correlation between progressed-year after ginseng harvest and soil chemical properties. Variation of soil chemical properties in descending order was Fe, Zn, P2O4, NO3, Mn. The content of Fe and Zn were great variation among inorganic chemicals of soil of farmer’s field. Electrical conductivity to induce physiological demage in excessive concentration showed highly significant positive correlation with the content of NO3 and K. As the progress of year after ginseng harvest, the content of organic matter and zinc was increased, while pH and Na were decreased in farmer’s field to cultivate ginseng. There were highly significant positive correlation between the progress of year after ginseng harvest and zinc content in farmer’s field to cultivate ginseng. Ratio of root rot of 2-year-old ginseng showed significant positive correlation with K content, and negative correlation in experimental field cultured by six rotation crops for one year. Conclusion : Root rot by soil pathogens was closely related with the content of potassium and zinc in soil chemical properties.
        100.
        2016.05 서비스 종료(열람 제한)
        Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.
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