• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.89-95
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• 1984

Sixty isolates of Dendrophoma obscurans isolated from 19 important strawberry growing areas of Korea were tested in vitro for resistance to thiophanate-methyl and iprodione. Naturally-occurring thiophanate-methyl-resistant isolates were about 43 percents of isolates tested, whereas iprodione-resistant isolates were 10 percents. All these resistant isolates except SU 1 and SU 2, which were highly resistant to thiophanate-methyl, showed a week level of resistance. Iprodione-resistant isolates were readily obtained in vitro, when mycelial disk of the fungus was incubated on PDA media containing iprodione at the concentrations of $1{\mu}g/ml\;and\;10{\mu}g/ml$, but no thiophanate-methyl-resistant isolate from the mycelia with or without UV irradiation. All these artificially-obtained iprodione-resistant isolates were showed a high degree of resistance. On the strawberry leaves, thiophanate-methyl and iprodione were no longer effective to all resistant isolates at the recommended concentration, and the protective value to highly resistant isolates was much less than that of weakly resistant isolates. Isolates resistant to thiophanate-methyl were also resistant to benomyl but iprodione-resistant isolates did not show cross-resistance to thiophanate-methyl, benomyl, captan and zineb. Captan controlled both thiophanate methyl-resistant and iprodione-resistant isolates as effectively as sensitive isolates.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.435-444
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• 2020

Background: As the Positive List System (PLS) is implemented in broad application to agricultural products, attention to the correct use of pesticides is also needed in the production of mulberry leaves and fruit. In this regard, three types of pesticides against mulberry popcorn disease were applied 2 - 3 times both in the field and greenhouses to prepare safety standards. Residual pesticide analysis was conducted on mulberry fruits and leaves. Methods and results: Three pesticieds, thiophanate-methyl, thiophanate-methyl·triflumizole and fluopyram registered as PLS pesticides for mulberry popcorn disease, were sprayed in the Wanju and in Buan regions, after which residual pesticide analysis was conducted using high-performance liquid chromatography (HPLC). As three pesticieds were either undetected or below the permissible level in mulberry fruit, demonstrating that they were suitable for safe spraying. However, 5.6 mg/kg of thiophanate-methyl was detected in the greenhouse after three application, which was slightly above maximum residue limit (MRL). Furthermore the level of thiophanate-methyl·triflumizole was higher than 0.2 mg/kg ("Gwasang No. 2" variety, spraying twice) or similar to 0.09 mg/kg ("Daesim" variety, spraying thrice) the permissible level (0.1T mg/kg) as the thiophanate-methyl was detected in mulberry leaves in the greenhouse. Conclusions: The spraying frequency for controlling mulberry popcorn disease in greenhouses should be limited to two times or less, especially when mulberry leaves are treated with thiophanate-methyl·triflumizole careful consideration is required if the leaves are to be used as food materials.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.65-71
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• 2010

This study was performed to investigate the inhibiting activity of etridiazole and thiophanate-mthyl on mycelial growth of Rhizoctonia solani and Pythium ultimum and the effect of inoculum density of each pathogen on the control efficacy of the mixture of etridiazole and thiophanate-methyl in a seedling assay test. In mycelial growth inhibition test, $EC_{50}$ values of etridiazole and thiophanate-methyl against R. solani were 15.87 and 9.34 ${\mu}g\;mL^{-1}$, while those were 0.2 and more than $500\;{\mu}g\;mL^{-1}$ against P. ultimum, respectively. Controlling activity of the mixture of etridiazole and thiophanate-methyl against damping-off of pepper and cucumber, caused by R. solani and P. ultimum was tested in a greenhouse. With the inoculation of R. solani, disease incidences of seedling in pepper were 73% and 95% at 0.5% and 1.0% of inoculum concentration, while in cucumber those were 55% and 62% at 1.0% and 2.0%. When P. ultimum was inoculated into soil by 2.0% of inoculum concentration, those in pepper and cucumber were 66.7% and 96.8%, respectively. The efficacy of the mixture was somehow affected by the concentration of R. solani. While each control value of the mixture was 94.4% and 90.7% in pepper and cucumber at low inoculum concentration (0.05%), the efficacy of the fungicide decreased in pepper and cucumber by 70.7% and 72.9% at high concentration of R. solani (0.1% in pepper and 0.5% in cucumber). However, the control value of the mixture was 100% in pepper and cucumber, irrespective of the inoculum concentration of P. ultimum, however, the increase of inoculum concentration in soil did not result in the decrease of the fungicide efficacy.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.306-312
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• 2006

The objective of this study was to compare the reduction of residues in/on mini-tomato by washing methods and to evaluate the relation of reduction rates in different pesticides. Mini-tomato was sprayed with three commercial pesticides, oxadixyl, thiophanate-methyl and chlorothalonil, and harvested for washing test as 0, 5 and 7 days elapsed. The reduction rates of oxadixyl in/on mini-tomato were 61, 11 and 4%, those of thiophanate-methyl were 89, 89 and 79%, and in case of chlorothlaonil, reduction rates were 84, 84 and 88%, respectively When mini-tomato at 0 day and 5 days after spray was washed by 0.02% of $Sur-ten^{(R)}$ solution, its pesticide residues were reduced by 81 and 55% on oxadixyl, 95 and 91% on thiophanate-methyl, and 97 and 98% on chlorothlaonil. When three wettable powdered pesticides with the same recipe were sprayed, their reduction rates in/on mini-tomato by washing with water at 0, 5 and 7 days were 76, 66 and 43% on oxadixyl, 91, 83 and 82% on thiophanate-methyl, and 65, 68 and 82% on chlorothlaonil, suggesting that the washing effect may be dependent on the amounts of active ingredients and inert types of the pesticides used.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.35-41
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• 2016

Earthworm cast is a harmful factor which reduces the uniformity of management of turfgrass and play quality in golf courses and playground. This research was conducted to carry out the efficacy of some pesticide (bifenthrin GR + clothianidin GR, ethoprophos GR, imidacloprid SC, picoxystrobin WG, thiophanate-methyl WP) and tee tree (Camellia oliefera) extracts against reducing earthworm cast in golf courses. All tested materials were acted reducing earthworm cast, thiophanate-methyl among them showed the highest effect reducing earthworm casts in golf courses. Tea tree extracts was occurred similar efficacy among tested chemical pesticides. However, pellet type byproduct of tea seed extract and liquid formulation of tea tree extract were better than granule formulation of them. Byproduct of tea seed and tea tree extract can be used for alternative biological management material for reducing earthworm cast in heavily casting occurrence area.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.198-206
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• 2003

To assess potential risk of the benzimidazole fungicides, their cytotoxicities were evaluated. Activities of LDH(Lactic dehydrogenase) in the culture fluid of CHL(chinese hamster lung) fiberoblast cell treated with 4.0, 16.0 or $32.0{\mu}g/mL$ of carbendazim for 24 hours were elevated 2.16, 2.94 and 2.64 folds compared to the control, respectively. DNA synthesis was inhibited by 45% at $2.0{\mu}g/mL$ of carbendazim. Benzimidazole fungicides showed high toxicity to cell and mitochondria of CHL cell by Giemsa and MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay. $IC_{50}$ by the Giemsa assay of thiophanate-methyl, benomyl, carbendazim and captafol were over 125, 1.2, 30.0 and $0.3{\mu}g/mL$, respectively. $IC_{50}$ by the MTT assay of thiophanate-methyl, benomyl, carbendazim and captafol were over 125, 18.7, 20.4 and $2.6{\mu}g/mL$, respectively. Inhibitory concentration of cell median proliferation by SRB (sulforhodamin B) assay for thiophanate-methyl, carbendazim, benomyl, and captafol were 17.4, 5.3, 1.5 and $0.5{\mu}g/mL$, respectively. Accordingly, benzimidazole fungicides inhibited DNA synthesis, mitochondrial function, cell proliferation and induced cell necrosis.

• 한국약용작물학회:학술대회논문집
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• 2007.05a
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• pp.127-128
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• 2007

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.129-136
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• 2008

Three benzimidazole pesticides commonly used in korean lettuce were subjected to a field residue trial to ensure safety of terminal residue in the harvest. The residual patterns of three benzimidazole pesticides, which were carbendazim, benomyl and thiophanate-methyl were examined after applying with the recommended dose in two types of korean lettuce (Chima and Chuckmeon) and their DT50 were calculated. In Chima lettuce, biological half-lives of carbendazim, benomyl and thiophanate-methyl were 2.56, 1.37 and 2.54 days, respectively and their required time under MRL(5.0 mg/kg as carbendazim) were 4.5, 2.2 and 1.0days. In Chuckmeon lettuce, biological half-lives of them were 3.41, 1.70 and 4.20 days, respectively and their required time under MRL were 5.4, 1.9 and 0.5days.

• Asian Journal of Turfgrass Science
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• v.15 no.1
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• pp.1-8
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• 2001

Antifungal activity of 20 chemicals registered to turfgrass diseases was evaluated. Among the chemicals, iprodione, benomyl, iprodione+thiram, pencycuron+tebuconazole, hexaconazole, and iprodione+thiophanate-methyl exhibited high antifungal activity to the dollar spot fungus. All isolates were greatly inhibited by the chemicals at the concentration over 32ppm($\mu\textrm{g}$/ml). However, sensitivity of the isolates to chemicals was varied at the lower concentration as 8 and 16 ppm as follows. The isolate originated from Ora golf course was resistant to iprodione and iprodione+thiophanate methyl, Gonjiam isolate to iprodion, Youngpyung isolate to iprodione+thiram, and Dogo isolate to iprodione+thiram, pencycuron+tebuconazole, and tebuconazole. It was found from this study that the varied chemical resistance among the isolates was positively related to the application time of the chemical in the golf course. Consequently, when a chemical was applied more often times than the others to the golf course, the fungal isolates originate from the field showed higher resistance to the former chemical. Effects of the chemicals on control of the dollar spot was evaluated in the field. All tested chemicals revealed over 70% disease control efficacy, however, mepronil+propiconazole was the best showing 83% control efficacy and followed by fenarimo, iprodione, terbuconazole, thiram, and thiophanate-methyl.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.347-353
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• 2005

Pesticide risk assessment for pesticide operators as well as for consumers has become one of the pesticide regulatory tools to reduce any unreasonable adverse health effects from pesticide use. The risk for pesticide operators can be quantified by comparing the acceptable operator exposure level(AOEL) with exposure level during pesticide application. This study is to evaluate the risk of benzimidazole fungicides application worker. The exposure level of pesticide applicators were calculated using Japanese operator exposure study tested with EPN 45% EC. The AOELs for pesticides were obtained dividing relevant lowest no observed abuse effect levels(NOAELs) for the exposure scenario into uncertainty factor, 100. For the non-cancer and cancer occupational risk assessment, $Q_1^*$ produced by US/EPA and life time average daily dose(LADD) calculated from average daily dose(ADD), treatment days per year, worked years for life time were used. Operator exposure for benzimidazole fungicides application were benomyl 0.2, carbendazim 0.36 and thiophanate-methyl 0.42 mg/kg/day. Short-term AOELs for benomyl, carbendazim and thiophanate-methyl were 0.3, 0.1, and 0.2 mg/kg/day, and long-term AOEL were 0.025, 0.025, 0.08 mg/kg/day, respectively. LADDs were benomyl 0.0038, carbendazim 0.0067, thiophanate-methyl 0.0081 mg/kg/day. The ratios of exposure to AOEL were $0.28{\sim}1.5$ for short-term and $3.73{\sim}9.88$ for long-term. Cancer risk for operator were $9.12{\times}10^{-6}$ for benomyl, $1.61{\times}10^{-5}$ for carbendazim and $1.13{\times}10^{-4}$ for thiophanate-methyl by the standard application scenario. The result showed 3 fungicides exceed the risk criteria, $1.0{\times}10^{-6}$. The above risk assessments were based upon conservative assumptions and therefore are believed to be protective of the applicator. To refine the risk at the more actual conditions, further risk assessment with more realistic data would be needed.