• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.216-222
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• 2009

The present study aims to monitor pesticide residues in cut flowers collected from the farms and markets. Cut flowers used in this study included rose, lily and chrysanthemum collected from June to September, 2008. Samples were collected once from farms in Hwasung, Goyang (Gyeonggi-do), Inje (Gangwon-do) and thrice from wholesale market in Namdaemunm, Yangjae and Gangnam (Seoul). Total of 24 pesticides (12 fungicides, 11 pesticides and 1 acaricide) were detected from samples collected from farm and total of 64 pesticides (25 fungicides, 36 pesticides, 1 acaricide and 2 fungicides) were detected from samples collected from wholesale market. The highest detection frequency of pesticide from farm was for carbaryl (15%) and for boscalid, fluacrypyrin, fluquinconazole, methomyl, pyraclostrobin, trifloxystrohin (10%), with overall detection of $0.1-36.99\;mg\;kg^{-1}$. While the highest detection frequency of pesticides from wholesale market was for carbaryl, fluquinoconazole and kresoxim-methyl (18.52%), methomyl (16.6%), and methiocarb and thiacloprid (12.96%) with overall detection amount of $0.1-56.2\;mg\;kg^{-1}$. Higher amount of pesticides were detected in leaves than in flowers. Among the pesticides detected, detection frequency of unregistered pesticides for rose, chrysanthemum and lily was 55%, 60% and 63% collected from farms and 47%, 60% and 89% collected from markets, respectively. These pesticides require registration and further monitoring in floricultural crops.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.424-429
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• 2010

To solve the problems with excessive accumulation of soil inorganic N and resulting saline soils from overuse of nitrogen fertilizer, the effect of sucrose application on decrease of soil inorganic N content and electrical conductivity (EC) was studied. Sucrose treatment greatly reduced ${NH_4}^+$-N content in soil. The amount of reduction was greater as the amount of sucrose treatment was increased. When ${NH_4}^+$-N content was reached the lowest point (about 10 mg $kg^{-1}$or lower), the C/N ratio, which determines the amount of sucrose treatment, was around 10 regardless of initial ${NH_4}^+$-N content. For the rate of ${NH_4}^+$-N reduction 15~36 hours was required to reduce the initial ${NH_4}^+$-N content to half, and 36~69 hours to lower ${NH_4}^+$-N content to the lowest point (about 10 mg $kg^{-1}$or lower). In addition, sucrose treatment greatly lowered ${NO_3}^-$-N content. In case of C/N ratio above 10, initial ${NO_3}^-$-N content of 348 mg $kg^{-1}$ was reduced to the lowest of 14~21 mg $kg^{-1}$. As for the rate of ${NO_3}^-$-N reduction by sucrose treatment, it took 36~60 hours for ${NO_3}^-$-N content to reach the lowest point for C/N ratio of 10 or higher, and it took 3 weeks, comparably longer time, for C/N ratio of 5. Lowering soil EC from sucrose treatment showed the same trend as ${NO_3}^-$-N content. As an important energy and carbon source for humankind, sugar should not be wasted and must be carefully applied to soil. In principle, the best way of preventing salt accumulation in soil is to optimize the fertilizer input. However, when over-fertilization should be dealt with, the sucrose treatment would be a possible and effective counter-measure to reduce overdosed nitrogen sources in soil.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.57-64
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• 2018

The fungus gnat, Bradysia difformis, has been recognized as an important pest of greenhouse crops. There is a need for research on the control of the fungus gnat. However, it is difficult to obtain many generations of the fungus gnat for several kinds of research. Indoor propagation is a very useful method for obtaining enough individuals in cases where the need is for larvae in soil. This study was conducted to determine the optimum growing media and temperature conditions for rearing the fungus gnat in the laboratory. Under experimental temperature conditions, hatching, pupation, and eclosion rates were the highest at $20^{\circ}C$. The developmental period of the fungus gnat was shortened with higher temperatures. The greatest number of eggs was an average of 144 at $20^{\circ}C$. Using different types of larvae growth media, the highest hatching rates were 84.7 and 84.4% in water agar and potato disks, respectively. The larval period was the shortest, at 14.7 days, when grown on potato disks. The highest pupation and eclosion rates were 85.2 and 82.6% on potato disks, respectively. The highest number of eggs was an average of 125.6 on potato disks. Regarding the effects of different growth media on the eclosion rate of B. difformis, the highest eclosion rate was 88.4% on the soil mix, and was 50% on oatmeal, 25% on shredded potato. The results of four different inoculation levels of larvae on eclosion rate of B. difformis showed that the highest eclosion rate was 84.7% for 1,000 larvae. The eclosion rate was shortened with a higher number of larvae inoculated/cage. In the growth medium used, 3,000 eggs were better for the initial level of inoculation, showing a relatively high emergence rate and short developmental period. Mass rearing procedures were explained in detail.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.75-86
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• 2008

Many kinds of environment friendly agricultural materials (EFAMs) were used for the plant protection, furthermore they support the growth of crops in the greenhouses and the kindly environment friendly farming. Natural enemies might be used for control of insect pest with EFAMs at the same space and time. For testing the toxicity of EFAMs against to natural enemies, 10 EFAMs were selected and tested in small greenhouses and farm's fields. In case of Harmonia axyridis larva, there was no predacious activity against cotton aphids in the block with EFAMMo L, EFAMPE D, EFAMME G and EFAMAE A, otherwise, aphid population was rapidly decreased in the control block without EFAMs. Both of Trialeurodes vaporariorum and Encarsia formosa population were slightly decreased in the block with EFAMs. There were significantly decreased in the block with IEFAM C, FEFAM D, EFAMSM Band EFAMPE D compared with control area. Especially, there was significantly maintained a very low population, both T. vaporariorum and E. formosa in the block with EFAMMo C. The parasitized ratio of Aphidius colemani is also very low in the block with EFAMs compared with control area. In the block with IEFAM C, FEFAM D, EFAMPE D and EFAMMo L, there were significantly different with control area in the number of mummies. Otherwise, in case of Diglyphus isaea and Liriomyza trifolii, there was no significantly different between blocks with and without EFAMs. In the block with EFAMMo C, Tetranychus urticae and Phytoseiulus persimilis populations were significantly maintained a very low level. However, the population of T. urticae was increased, but P. persimilis was decreased in the block with EFAMMo L.

• Journal of Radiation Protection and Research
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• v.13 no.1
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• pp.31-41
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• 1988

In case of the acute intake of radionuclide, an early medical treatment may be necessary, but the little is established the procedures to decontaminate the victims of internal contamination in Korea. The purpose of the present investigation is to study chemical agents to remove radiocobalt from the victims and to provide a more reliable procedure for the treatment. The removals of radiocobalt from the NIH-CGP)mice injected intraperitoneally with $1{\mu}Ci$ of $^{58}Co$ as $CoCl_2$ were investigated with doses of either $CaNa_3$ DTPA 8.4mg/0.2ml saline, $CoNa_3$ DTPA 8.4mg/0.2ml saline, or saline 5ml. The radioactivity was determined by MCA and Ge-detector on 4, 8, 12, 48 hours and 7 days for the whole body, organ distribution and urine excretion. Six mice per each group were sacrificed for the measurement of cobalt retention in the parenchymal tissue. The cobalt trisodium chelate had a pronounced effect on reducing the whole body retention and increasing the excretion rate. Regarding to the systemic protective effects, $CoNa_3$ DTPA, $CaNa_3$ DTPA and saline were effected significantly in order. In conclusion, the extrapolations from these results to human were suggested that the rapid administration of cobalt trisodium chelate and an amount of saline to the contaminated person after internal contamination of radiocobalt were markedly increasing the decontamination effects.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.328-332
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• 2007

This study was conducted to investigate the effects of high concentrations of salts in soil on the growth, yield, quality, photosynthetic rate, and mineral uptake of tomato ('House Momotaro') in pot cultivation. The growth of tomato such as plant height, top plant weight and root weight decreased as the concentrations of salts in soils increased. Yield decreased by 31% and 41% in EC 5.0 and $7.5dS{\cdot}m^{-1}$, respectively compared with the salt concentration of EC $1.5dS{\cdot}m^{-1}$. Yield reduction was caused by low mean weight and number of fruit if at high salt concentration in soil, and affected by low photosynthetic rate and water potential in leaf, The rate of blossom-end rot was highest (16.7%) in EC $7.5dS{\cdot}m^{-1}$ and increased as the concentrations of salts in soils increased. The contents of soluble solids and titratable acids showed a tendency to increase with increasing the concentrations of salts in soils. Photosynthetic rate, water potential and stomatal conductance in leaf decreased as the salt concentration in soil increased. The higher the salt concentration in soil, the lower the mineral uptake such as T-N, P, K, Ca and Mg but, the higher the content of Na.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.9-16
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• 2002

This study was conducted to develope the new solid separating system which can be efficiently and economically removed the solid parts in high pollutants concentration of pig slurry. The pollutants concentration, BOD$_{5}$ , COD and SS of the slurry used in this study was 15,990($\pm$2,389)mg/l, 20,004($\pm$5,512)mg/l and 26,486($\pm$5,935)mg/l, respectively. After removal of solid part in slurry, the pollutants concentration, BOD$_{5}$, COD and SS was change into 5,617($\pm$690)mg/l, 5,553($\pm$633)mg/land 1,456($\pm$341)mg/l, respectively in the Fixed biological membrane tank. The reduction of the pollutants concentration of suspend liquid through membrane will be allowed to greatly improve the water purification by an Activated sludge method. This separating system consisted of a temporary storage, a circulating tank and a Fixed Biological membrane tank. A temporary storage which has a draining system of screw type and an aeration device played a tremendous role in draining the solid by filled an aeration of 0.3 l/min. A Fixed Biological membrane tank of which a styrofoam filled in a 2/3 volume as a Biological media was fixed by a stainless steel net (pore size : 0.5mm) to separate the liquid layer of influx in them. The separating system efficiency factors were the speed of screw motor, cycle number of slurries in a circulating tank and moisture contents of solid effluent through the screw path. Although the pollutants concentration was very variable in temporary storage, the final concentration of $BOD_5$ and SS, except COD of the suspended liquid in a Fixed biological membrane were not different regardless of cycle number of a circulating tank. Moisture contents of effluent from temporary storage was 73% under the speed 1 ppm of screw motor and 62% under the 1/4rpm of it.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.33-40
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• 2006

Many soil amendments have been used nowadays to improve physical and chmical condition of turf soil, which might ultimately optimize turfgrass growth in golf courses. This study was carried out to Investigate the effects of new organic soil amendment containing pig excreta 50% and sawdust 50% on growth of zoysiagrass (Zoysia japonica L.) and kentucky bluegrass (Poa pratensis L.) in greenhouse. Three applicable treatments with soil mixtures of 10, 20, and 30% (v/v) animal organic soil amendment (AOSA) with sand, were tested for chemical property, physical property, visual quality and root length of zoysiagrass and Kentucky bluegrass. As results, application of $10{\sim}30%$ AOSA mixtures were proper to grow turfgrass in soil nutrition. Especially, the treatment with 20% AOSA mixtures showed 0.7% in organic matter, which meets to green standard of USGA. Also, 30% AOSA mixtures was 1.1% in organic matter, which might be desirable for zoysiagrass-planted golf courses in Korea. It was turned out that addition of AOSA decreased the hydraulic conductivity in soil physical property Because the sand possess high hydraulic conductivity, it is recommended to combine $10{\sim}30%$ AOSA with sand in order to sustain soil balance. The treatment with $10{\sim}30%$ AOSA noticeably increased visual quality of both zoysiagras and Kentucky bluegrass during 90 days. However, treatments with either 20% or 30% AOSA were effective to develop root length of zoysiagrass but treatments with 20% AOSA were more effective than that of 30% AOSA mixtures to promote root length of Kentucky bluegrass at 60 days. In conclusion, considering all vital factors such as visible quality, root growth, organic matter content, and economical efficiency, was taken, it is recommended that a $20{\sim}30%$ mixture of AOSA with sand is good for the growth of zoysiagrass and 20% mixture for Kentucky bluegrass.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.355-365
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• 2014

It has been unclear whether the diamondback moth, Plutella xylostella can overwinter in Korean field conditions. This study determined overwintering conditions of P. xylostella by conducting field exposure tests based on its cold tolerance and monitoring overwintering populations by direct examination of overwintering larval habitats and capturing adults with sex pheromone traps. In addition, the overwintering populations were analyzed using polymorphic genetic markers to trace their sources. When all immature stages of P. xylostella were exposed to $-5^{\circ}C$, which was the temperature much above their supercooling points, they significantly suffered with direct cold injuries, where larval stage was most tolerant to the cold injury. However, the exposure to $5^{\circ}C$ for a long period (4 weeks) did not give any significant cold injury to nonfeeding stages, while this treatment gave lethality to larval stage without diet. When all developmental stages of P. xylostella were exposed to open field conditions during winter, they exhibited significant decreases of survival rates. However, some protected and indoor conditions reduced the cold injuries and the diet provision significantly increased larval survival rates. Adult monitoring with sex pheromone during winter period indicated that the first captures were observed at similar periods at different locations (${\approx}260$ Km apart). The overwintering adults were captured until early April. Genetic variation of these overwintering populations was analyzed with polymorphic molecular markers, indicating significant genetic divergences among the overwintering populations. This study indicates that P. xylostella can overwinter in southern Korean fields or some protected greenhouses with host plants.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.99-107
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• 1992

Effects of the indigenous Vesicular-arbuscular mycurrhizal fungi(VAMF) on early growth response of greenhouse grown crops were experimented. This study was done to evaluate the benefit of indigenous VAMF inoculation on the early growth and the subsequent growth after transplanting of some crops such as cucumber, tomato, hot pepper, eggplant, and melon. Leaf area, shoot dry weight, and plant length of mycorrhizal greenhouse crops showed the tendency of significant or no significant increase over control plants receiving no inoculation. The levels of VA mycorrhizal colonization were increased with plant growth, and infection rates of horticultural crop except hot pepper around one week after transplanting were decreased, while that of 8 weeks after emergence of mycorrhizal seedlings were increased again and infected by around 50% at harvesting time. In spore densities in the rhizosphere soil of craps experimented, the number of spore ranged from $72.7{\pm}26.3$ to $100{\pm}10.3g^1$ on dried soil basis and high density showed in both cucumber and tomato. Total nitrogen contents in shoots were lower in the mycorrhizal plants than non-mycorrhizal one, whereas P uptake in mycorrhizal hot pepper and tomato were highly ramarkable. The K contents in the shoots of mycorrhizal cucumber and eggplent were highly enhanced. Inoculation of the indigenous VAMF enhanced shoot Ca and Mg in both tomoto and melon. The contents of Fe, Zn, Mn and Cu in shoots of mycorrhizal crops were higher than non-mycorrhizal plants and vice versa in case of eggplent. Inoculation of the indigenous VAMF to horticultural crops were effective for alleviation of transplanting shock, and pretransplanting infection improved subsequent growth by reducing the time required for establishment of a functional mycorrhizal symbiosis following transplanting.