• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.265-285
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• 2004

Objectives: The acute toxic effects of pesticide are well known. Concern has also been expressed that long-term exposure may result in damage to the central nervous system. This study was conducted to test the hypothesis that central nervous system symptoms might occur due to pesticide exposure. Methods: In a cross-sectional study, first, cumulative exposure index (CEI) was estimated. Neurologic symptoms (Q-16 questionnaire) for 541 farmers (exposed to pesticides) were compared with 119 non-exposed persons in spraying season nine rural areas in Korea. Results: The pesticides poisoning rates for last 3 months were 67.2% for orchard farmers, 55.3%for dry field farmers, and 20.5% for husbandry farmers, respectively, showing significant difference (p<0.001). Compared with non-exposure group, exposure groups (especially, orchard farmers) reported significantly more neurologic symptoms and had a higher overall neurological symptoms score (p<0.001). Factors related to the positive neurological symptoms (answers "yes" to six or more of Q-16 questionnaire) adjusted for age, sex, education level, smoking and alcohol drinking were type of farming (OR 3.08, 95% CI 1.50-6.30 in orchard farmers vs non-exposure group), CEI (OR 2.75, 95% CI 1.12-6.78 in Q3 vs Q1), past poisoning (OR 1.97, 95% CI 1.21-3.20 vs normal), current mild poisoning (OR 3.03, 9500 CI 1.47-6.22 vs normal) and current moderate poisoning (OR 6.34, 95% CI 3.03-13.25 vs normal), respectively. Conclusions: These results suggest that long-term exposure to pesticides appears to be associated with subtle changes in the central nervous system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.237-244
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• 2012

Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV) cause severe diseases in winter barley in Europe and East Asia. We investigated the effect of different level of resistance to virus disease on the plant growth and yield in whole-crop barley. In the virus infection, BaYMV was detected all tested cultivars in first diagnosis at 30th March. BaYMV infection was identified only in the susceptible Sunwoobori in 6th April, but not in the Yuyeon (moderate, M) and Youngyang (moderate resistant, MR) cultivars. Plant height was restrained about 14.6~32.9% in overwintered plant regeneration stage depending on the resistance of each cultivar. The tiller numbers also reduced to 8.7~19.7% by BaYMV infection in overwintering season. We evaluated culm length, spike length, and spike number in the virus-infected field and non-infected field. For the culm length, Youngyang (MR) reduced only 14.5% by BaYMV. However Sunwoo (susceptible, S) and Yuyeon (M) cultivars were decreased to 24.8~42.7%. The spike length and spike number also affected to 8.9~21.3% and 24.3~31.0%, respectively, depending on the resistance. After harvesting, dry-matter yield of whole crop yield reduced by approximately 21.6~58.0% according to cultivar resistant degrees. For example, Sunwoobori (S) decreased 58.0% in comparing to non-infected field. The grain yield was also significantly reduced in virus infected cultivars. Sunwoobori (S) was severely decrease more than 60.0%. Yuyeonbori (M) and Youngyangbori (MR) also decreased 30.0~47.5% by the viral infection comparing to those in the non-infected field.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.307-319
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• 1988

In order to determine the contents of lead, cadmium and zinc, the tissues of the crussian carp, Carassius carassius, collected from the middle streams of the Nakdong river were examined. During the dry season from 8 to 15, March, 1987, six loci were selected to sample the fish and river water; five of them were the midstreams of the Nakdong river i. e., the vicinities of the Andong dam, the Nakdong bridge, the Waegwan bridge, Gangjung and Gaepori, the other one was the Kumho river around the Paldal bridge(see Fig. 1). The microanalyses of lead and cadmium contents were undertaken by the atomic absorption spectrophotometer(Model IL-551) connected with CTF-IL 655, while that of Zinc by the flame method with IL551 only. The contents of lead and cadmium in water sampled from Gaepori distant from about 30km downward from the junction with the Kumho river were about 1.5 times higher than those from Gangjung distant about 0.5km upward from the junction, and the content of zinc from Gaepori was slightly higher than that from Gangjung. However, the contents of lead and cadmium in water sampled from Gaepori were three fifth of those from the vicinity of Paldal bridge far about 2km upperward from the junction. In the other words, the contents of lead and cadmium in the samples from the vicinity of the Paldal bridge were about 2.5 to 3 times higher than those from the Gangjung and 5 times higher than those from the Andong dam. The contents of the heavy metals in the tissues of Carassius carassius were relatively consistent to those of the aquatic environments where the fish were collected, with higher contents in the tissues of the crussian carp collected from the vicinity of Gaepori and the Paldal bridge which were so much polluted than in those from other loci in upper stream from the junction. And the contents of lead and cadmium in tissues were positively correlated with the age of the fish, however, that of zinc was not. The contents of lead in bone of crussian carp from the vicinity of the Paldal bridge in the group of 0-1 year old fish were similar to those of 4-5 years old fish from Gaepori, and higher than those of 3-4 years old fish collected from the upper stream of the junction. It is likely that fishing from Gaepori and the paldal bridge is not recommended, and all the industrial producers have to pay intensive attention to the water pollution due to the sewage disposal.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.148-156
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• 2011

The purpose of this study is to analyze the patterns of forest fire possibly related with Asian dust event and carry out a correlation analysis between forest fire occurrence and existence or not of the Asian dust event during dry seasons i.e. February to May in 2000 to 2008. To study the correlation of forest fire and Asian dust, we surveyed information of Asian dust observations, forest fire statistics, fire danger rating index, weather data such as temperature, relative humidity and wind speed of the day occurring the forest fire. As a consequence of analysis, the regional frequency of Asian dust was the highest in Gyeonggi and Chungbuk divisions. Frequencies of forest fire occurrence by the Asian dust events were the highest in the day before three days of the Asian dust event. The highest frequent regions of forest fire occurrence were district of boundary line between Gyeonggi and Western of Gangwon, Chungbuk and Gyeonbuk inland. The correlation between forest fire and fire danger rating index showed the high correlation with the day before three days and after three days of the Asian dust event. These correlation coefficients were 0.50038 and 0.53978 to 1% significance level. The result of analysis between the frequency of forest fire occurrence and wind speed had a highly negative relationship at all the Asian dust days, the day before and after three days. The correlation coefficients had been -0.58623 to -0.61245 to 1% significance level. Relative humidity showed a little of negative relationship with forest fire occurrence in -0.2568(p ${\leq}$ 0.01) for the Asian dust day and -0.35309(p ${\leq}$ 0.01) for next three days. Moreover, at the day before three days of Asian dust events, it was -0.23701 to 1% significance level. However, the mean temperature did not correlate with frequency of forest fire occurrence by Asian dust events at all.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.223-231
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• 2017

This study was conducted to determine the impact of elevated temperature based on climate change scenario on growth and bulb quality of extremely early-maturing onion (Allium cepa L. cv. Singsingball) in the temperature gradient tunnels. There were treated with 3 groups, one is a control group (ambient temperature, mean temperature at $9.8^{\circ}C$), another ambient temperature $+2^{\circ}C$ (mean temperature at $12.0^{\circ}C$), and the other ambient temperature $+5^{\circ}C$ (mean temperature at $14.3^{\circ}C$). Compared with the control, plant height, neck diameter, leaf area, top fresh weight and dry weight were significantly increased at ambient $+2^{\circ}C$ temperature. Bulb diameter and bulb weight was highest at ambient $+2^{\circ}C$ temperature (mean temperature at $12.0^{\circ}C$) during the growth period. Bulb/neck diameter ratio, over 2.0 a good indicator of development of bulb, increased rapidly at ambient $+2^{\circ}C$ temperature. This result suggests that extremely early-maturing onion (Allium cepa L. cv. Singsingball) could maintain the higher productivity and bulb quality at ambient $+2^{\circ}C$ temperature. On the contrary, $5^{\circ}C$ higher than atmospheric temperature shows negative effects on yields under a future climate change scenario.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.128-135
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• 1998

The experiment was carried out to obtain basic informations on sod culture using water foxtail in apple orchard at Kyeongbuk Provincial RDA in 1996 to 1997. Period of seedling emergence varied with sowing time and accumulative temperature. Sowing at Nov. 25 required longer than 100 days, while it needed only 8 days when water foxtail was sowed at Sep. 20. In a view of accumulative temperature, sowing at March 15 needed $139^{\circ}C$ but it required about $1,000^{\circ}C$ at August 10. This result showed that the seed of water foxtail has strong summer-dormancy in natural condition. Water foxtail had s-shape growth curve during growing season, and growth rate was the highest from March to May in this period. Plant height increased 2 times and 4 times for dry weight from March 20 to April 20. However, growth was decreased by summer depression after May. Major weeds in apple orchard were horseweed, akino-nogeshi and shepherd's-purse. These species were suppressed by the dominance of water foxtail. Water foxtail as a cover plant could be used for a method of weed control instead of herbicide in apple orchard.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.207-211
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• 1985

This study was conducted to determine the effects of shade (full day light; 100, 80, 60, 40 and 20%) and fertilization levels (high; $N\;30kg-P_2O_5\;35kg-K_2O\;30kg$, moderate; $N\;20kg-P_2O_5\;25kg-K_2O\;20kg$, and low; $N\;10kg-P_2O_5\;15kg-K_2O\;10kg$) of forest pasture on intake palatability of Korean native goat, and the effects of shade under the conditions of 50% shaded forest pasture and full day light pastures on grazing behavior. This experiment was done at the experimental field of Chungnam National University, in Taejon, from 1983 to 1984. The results obtained are summarized as follows: 1. The dry matter intake, R.I.I. and Touch number of Korean native goat were affected by the shade degrees and fertilization levels, generally the increase of the fertilization level and high shading degree increased the NO_3-N$ contents in the plants, but decreased the soluble carbohydrate contents. It means that the decrease of the utilization of the shade culture grasses is due to the decreased intake palatability of forest pastures, particularly the conditions high fertilization level and above 60% of shading level seemed to have a nitrate stress. 2. Grazing time of forest pastures by Korean native goat tended to be spend more time than full day light pastures, also tendency of the major grazing activity tended to be graze continuously without difference of variation of grazing time within a day. Considering of the characteristies os shade, the intensive utilization of forest pastures seemed to be most effective during the high temperature season in August.

• FLOWER RESEARCH JOURNAL
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• v.19 no.1
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• pp.15-21
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• 2011

This study investigated the effect of soil mulching materials and methods on weed occurring for the growth and flowering characteristics in Gypsophila plants cultivation. For mulching materials were used black polyethylene (PE) film, black polypropylene (PP), and green polypropylene, and these were mulched in both ridge and furrow (BRF) or only furrow, respectively. The weed was occurred total $146.2g/m^2/yr$ as dry weight in non-mulching, but $4.1{\sim}4.2g/m^2/yr$ in BRF mulching by black or green PP. Also weed control were yearly required 27.9 persons/10a in non-mulching, whereas 2.4 persons/10a in BRF mulching by black or green PP. Flower budding and blooming were roughly delayed in non-mulching and furrow mulching. Flowering characteristics such as flower stalk length, primary branches number, and stem firmness were remarkably improved in BRF mulching of black or green PP. Cut flower yield was increased on black BRF mulching or green PP in summer cultivation, while green PP BRF mulching showed better yield in in autumn cultivation. Mortality rate of Gypsophila plants after summer season was lowest as 12.4% in furrow mulching with black PP, followed by about 19.0% in green PP mulching, but highest as 39.0% in BRF mulching with black PE film. Rosette formation rate was lower in furrow than BRF mulching, and was lowest as 13.1% in BRF mulching with green PP, followed by 15.2~15.8% in BRF mulching with black PE film or black PP. So it was thought that BRF mulching with green PP was highly effective in weed control and improvement of yield and cut flower quality in Gypsophila plants cultivation.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.237-251
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• 2011

This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.321-329
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• 2018

A study was carried out to determine the influence of climatic environments on the growth characteristics and bulb quality of extremely early-maturing type onion grown at different altitudes, such as 60m, 200m, 350m and 700m above sea level (ASL). The mean air temperature during the growing season of extremely early-maturing type onion (October 18 to April 27) was $10.8^{\circ}C$, $9.6^{\circ}C$, $8.1^{\circ}C$ and $6.1^{\circ}C$ at 60m, 200m, 350m and 700m ASL. The mean air temperature during the bulb growth period (March 16 to April 14) was recorded $10.5^{\circ}C$, $9.4^{\circ}C$, $7.9^{\circ}C$ and $6.0^{\circ}C$ at 60m, 200m, 350m and 700 m ASL. Plant height, neck diameter, leaf number, leaf area, top fresh weight and top dry weight were significantly increased in growing of extremely early-maturing type onion at 60m ASL. Bulb/neck diameter ratio increased rapidly under the same temperature regime. The diameter and weight of the bulb were also the largest at 60m ASL during the bulb growth period (daily mean temperature of $12.5^{\circ}C$). At 60m ASL, there was the highest bulb size like a height, diameter and weight of bulb related directly on onion yield in the bulb growth period from March 16 to April 14. In contrast, yield and bulb quality were considerably decreased at 700m ASL during the bulb growth stage (daily mean temperature of $8.4^{\circ}C$). The quantity of extremely early-maturing type onion has gradually decreased as the daily average temperature drops below $12.5^{\circ}C$ during the bulb growth stage (March 16 to April 14). As a result, the lower temperature (daily mean temperature below $12.5^{\circ}C$) during the bulb growth stage significantly decreased the size and quantity of bulb in direction proportion.