• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.205-210
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• 1998

This study was carried out for the dietary safety based on the level of pesticide residues in 19 kinds of agricultural products consumed in Kangwon-do, Korea. From April 1995 to December 1997, eight organochlorine pesticides in 673 samples were analyzed by using GLC-ECD. According to the results, one kind of pesticides were detected in 159(23.6%) samples and two kinds were in 24(15.1%). While Chlorobenzilate, Dicofol and Tetradifon were not found. Detection ranges of pesticides were $0.001{\sim}0.117ppm$ for DDT, $0.001{\sim}0.095ppm$ for ${\gamma}-BHC$, $0.001{\sim}0.067ppm$ for ${\alpha},{\beta}-Endosulfan$, $0.003{\sim}0.250ppm$ for Chlorothalonil and 0.033ppm for Captafol. Average residues were 0.006ppm for DDT, 0.009ppm for ${\gamma}-BHC$, 0.008ppm for ${\alpha},{\beta}-Endosulfan$, 0.024ppm for Chlorothalonil and 0.033ppm for Captafol, respectively. Consequently, all of the organochlorine pesticide residues in the analyzed samples were within the maximum residue limits.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.185-191
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• 2001

To obtain the basic information for degradation of remaining pesticide accumulated in cultivated soil of Honam area, the resistant bacterial strains were investigated in Chlorothalonil(TPN). Mancozeb, Bentazone, and Butachlor levels of 100, $500{\mu}g\;ml^{-1}$, and degradation of TPN by TPN-resistant bacteria in sterilized soil was studied under TPN levels 0, 10, 50 and $100{\mu}g\;g^{-1}$. A number of resistance strains were decreased with higher at concentration level of pesticide, and were higher in greenhouse than upland or paddy soil. The resistance of bacteria was strong in other of Bentazone> Butachlor> TPN> Mancozeb. The percentage of bacterial strains of resistance for pesticides isolated from the cultivated soil were the highest in Acinetobacter spp. and Corynebacterium spp., and the lowest in Moraxella spp. A number of TPN-resistant strains were the highest at the TPN level of $10{\mu}g\;g^{-1}$, and 5 days after strains inoculation, and were higher in Pseudomonas spp. TD-25 than TC-23 or strains in non-sterilized soil. The degradation of TPN was fast in order of strain TD-25>strain in non-sterilized soil >TC-23.

• Research in Plant Disease
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• v.14 no.2
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• pp.102-106
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• 2008

The single application of Bacillus subtilis QST713(BS QST713) mixed application with fungicides and alternate application were treated to examine the control of alternaria leaf blight of Panax ginseng. Control value of alternaria leaf blight by single application of BS QST713 at 10 days interval was 83.3%, and those of single application at 10 days interval was $80.4{\sim}83.7%$ by azoxystrobin, chlorothalonil copper sulfate basic, copper sulfate basic, kresoxim-methyl, difenoconazole, mancozeb. When mixture of BS QST713 and fungicides were applied at 14 days interval, the control value of alternaria leaf blight were 83.6% by BS QST713 and mancozeb, and 82.6% by BS QST713 and azoxystrobin. However, mixture of BS QST713 with difenoconazole, kresoxim-methyl, copper sulfate basic and chlorothalonil copper sulfate basic exhibited the disease control values from 61.1% to 76.4%, which showed slightly lower control efficacy. In Daejeon, the alternate application of BS QST713 followed by copper sulfate basic with 14 days interval was 85.9% in control value, which showed the best control efficacy. The alternate application with other tested fungicides slightly decreased to $55.5{\sim}78.2%$ in control value. However, the alternate application of BS QST713 followed by fungicides showed very high control efficacy, which were approximately 90% in Muju, Jeonbuk Province. Consequently, the single, mixed or alternate application of BS QST713 and fungicides could be recommended as a control method to reduce the amount of fungicides.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.241-246
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• 2016

BACKGROUND: Recently, the widespread distribution of pesticides in the hive has been of concern about pesticide exposure on honeybee (Apis mellifera L.) health. Larval toxicity was adapted to assess the synergistic and antagonistic interaction of cumulative mortality to the honeybee larvae of the four most common pesticides detected in pollen. METHODS AND RESULTS: Acetamiprid($3.0{\mu}l/L$), chlorothalonil ($803.0{\mu}l/L$), coumaphos ($128.0{\mu}l/L$), and tau-fluvalinate ($123.0{\mu}l/L$) were tested in combination; binary, ternary and four component mixture. Larvae were exposed to four pesticides mixed in diet at the average levels detected in pollen. As a result, synthetic toxicity was observed in the binary mixture of acetamiprid with coumaphos. The binary and ternary component mixtures of tested pesticides have mostly demonstrated additive effect in larval bees. The significant antagonistic effects were found in four parings of mixtures including chlorothalonil added to acetamiprid/tau-fluvalinate or acetamiprid/coumaphos/tau-fluvalinate, and tau-fluvalinate added to acetamiprid/chlorothalonil or acetamiprid/coumaphos/chlorothalonil. CONCLUSION: Interactions between combinations of four pesticides showed mostly additive or antagonistic effects in larval bees. Therefore, predicting the larval mortality of pesticides mixtures on the basis of the results of single pesticide may actually overestimate the risk. We suggest that pesticide mixture in pollen be evaluated by adding their toxicity together for complete data on interactions.

• Food Science and Preservation
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• v.9 no.1
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• pp.46-50
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• 2002

This study was carried out for dietary safety based on the level of pesticide residues in 17 kinds of the agricultural products (apple, cabbage, cabbage kor, carrot, cucumber, pepper, onion, potato, radish, spring onion, pumpkin, lettuce, garlic, drapwort, spinach, leek crown daisy) consumed in Kyunggi-do and Inchon-city that provided for the army. From January 1998 to December 2001, ten organochlorine pesticides in 1075 samples were analyzed by using GC-ECD. According to the results, one kind of pesticides was detected in 135(12.5%) samples, and two kinds were in 7 (5.18%). While dicofol and tetradifon was not fecund. Detection rate of pesticides were 9.02% for $\alpha$, $\beta$-endosulfan, 2.8% far chlorothalonil, 0.46% for γ-BHC, 0.40% for chlorobenzilate, 0.33% for folpet, 0.28% far DDT, 0.15% for captafol, and 0.11% for captan. Dectection ranges of pesticides were from 0.001 to 0.092 ppm for $\alpha$, $\beta$-endosulfan, from 0.003 to 0.023 ppm for chlorothalonil, from 0.003 to 0.006 ppm far γ -BHC, from 0.001 to 0.003 ppm for DDT, from 0.009 to 0.095 ppm for folpet, 0.05 ppm for captan, 0.01 ppm for captafol, and 0.008 ppm far chlorobenzilatel respectively. Consequentlyl all detected pesticide levels in samples were below maximum residue limits(MRLs) in Korea and Codex.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.422-428
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• 2005

In vivo antifungal activity of 44 fungicides consisting of 3 clubroot fungicides, 7 Oomycetes fungicides, 7 botriticides, 7 blasticides, 9 sterol biosynthesis inhibitors, and 11 broad spectrum fungicides were investigated against Plamodiophora brassicae, the causal agent of clubroot disease in Chinese cabbage. When fluazinam, flusulfamide and cyazofamid, commercial fungicide to control clubroot of Chinese cabbage in Korea, were applied to infested soil, club formations by P. brassicae were strongly inhibited at pot (35 $cm^2$) per 0.63 mg. Ethaboxam and cymoxanil, Oomycetes fungicides, completely controlled Chinese cabbage clubroot at 5 mg/pot, but cymoxanil represented sever phytotoxicity. Besides, dichlofluanid and procymidone of botriticides effectively controlled the development of Chinese cabbage clubroot at 2.5 mg/pot. Chlorothalonil, quintozene and trichlamide, broad spectrum fungicides, showed disease-control efficacy of 85%, 100% and 100% at 2.5 mg/pot, respectively. Most of sterol biosynthesis inhibitors displayed the strong antifungal activity against P. brassicae on cabbage seedlings and plant growth -retarding activity. From these results, 7 fungicides were selected and further tested in vivo antifungal activity against P. brassicae in glasshouse. Among them, ethaboxam showed the most antifungal activity against P. brassicae on cabbage seedlings, followed by fenarimol, procymidone, nuarimol and chlorothalonil.

• Analytical Science and Technology
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• v.21 no.6
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• pp.459-473
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• 2008

Antifouling agents including tributyltin (TBT) compound and its derivatives have been used for many years, but the usage of TBT in Korea was legally restricted in 2003, due to its significant environmental impact. Following this, many new alternative antifouling agents have been used. In this experiment, four major antifouling agents were selectively analyzed to study their release in seawater and tidal flats on the Korean Peninsula. These new antifouling agents were extracted from the seawater and tidal flats using a liquid-liquid extraction method and microwave extraction, respectively. The measured concentrations of Irgarol 1051, Sea-Nine 211, Dichlofluanid and Chlorothalonil ranged from N.D.$-23.80ng/{\ell}$, N.D.$-15.30ng/{\ell}$, N.D.$-61.69ng/{\ell}$ and N.D.$-4.19ng/{\ell}$ in the seawater samples and from N.D.-159.45 ng/g, N.D.-476.57 ng/g, N.D.-59.79 ng/g and N.D.-21.27 ng/g in the tidal flat samples, respectively. Interestingly, these new antifouling agents were not detected in any area in the tidal flats at Pusan, whereas a certain amount of them was found in the seawater.

• Research in Plant Disease
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• v.17 no.3
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• pp.410-412
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• 2011

Since the late 2000s, a serious Entomosporium leaf spot disease, caused by Entomosporium mespili, has been found frequently on leaves of Eriobotrya japonica and Photinia glabra at a nursery station in Goheung and Jeju, respectively. Studies were conducted to select fungicides that would effectively control Entomosporium leaf spot. Among the three fungicides tested, weekly foliar applications of propiconazole and chlorothalonil effectively reduced disease severity on E. japonica and P. glabra showing control value of 64.1% and 87.6%, respectively. Weekly treatments of thiopanate methyl were less effective. Propiconazole controlled the disease, but, it was phytotoxic to P. glabra.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.74-80
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• 1996

This experiment was conducted to obtain the basis of degradation of remaining agricultural chemicals accumulated in upland soils of Honam district in Korea. The population. relative growth rate(RGR). chlorothalonil(TPN)-degradation ability and bacterialogical characteristics of TPN resistant strains were investigated in TPN levels of 0, 25, 50, 100 and $500{\mu}l/ml$ compared with Mancozeb. A number of TPN-resistant bacteria were differ in the area of examined and were decreased with higher levels of TPN. The resistance of bacteria was stronger in TPN than Mancozeb but the resistance of fungi was vise versa. RGR of bacteria in the culture was the highest at the level of $50{\mu}l/ml$ and the lowest in $500{\mu}l/ml$ of TPN. TPN-degradation ability of bacteda isolated in various TPN levels was varied : only 8 percentage of bacteria showed 75 percentage or more degradation ability. The higher the concentration in TPN resistance, the larger the number of strains carried great ability to decompose pesticide residues. The strains having higher decomposition ability was rod-shapes cells and senstive to heat. Analyses of the indol production, methyl red, and V-P test have given similar results, with negative reaction in all these strain, while the other biochemical characteristics were differ in the strains. Based on these, these strains might be classified into Pseudomonas sp., Corynebacterium sp., Acinetobacter sp. and Moraxcella sp.

• Research in Plant Disease
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• v.30 no.2
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• pp.131-138
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• 2024

The effects of five fungicides on the spore growth phase of Alternaria dauci, which causes carrot leaf blight, were tested using the spore viability assay (SVA) and agar dilution method (ADM). The average EC₅₀ values for chlorothalonil against seven isolates of A. dauci examined by SVA and ADM were 14.21 ㎍/ml and more than 100 ㎍/ml. Dithianon and folpet also had lower EC₅₀ values in SVA than in ADM, while iminoctadine trisalbesilate had lower EC₅₀ value in ADM. For fluazinam, the EC₅₀ values of SVA and ADM were 1.63 and 2.40 ㎍/ml, respectively. As EC₅₀ values of five fungicides according to the spore growth phase of A. dauci KACC 42997, the efficacy of each fungicide as chlorothalonil, dithianon, and folpet decreased when treated after spore germination rather than when treated with spores before germination. However, iminoctadine tris-albesilate was more effective when treated after spores germinated than when treated before treatment. The excellent effect of fluazinam on the pathogen was maintained until A. dauci KACC 42997 was cultured in potato dextrose broth for 6 hr and the germ tube grew beyond the size of the spore. However, when treated with iminoctadine tris-albesilate and fluazinam after culturing for 12 hr, as the EC₅₀ values of the two fungicides increased to 8.87 and 20.65 ㎍/ml, their efficacies decreased. The results of this study show that the treatment time of the fungicide should be determined by considering the effect of the fungicide on the spore growth phase of pathogens.