• Toxicological Research
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• v.24 no.1
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• pp.87-91
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• 2008

The present study was conducted to monitor the level of triflumizole residues in fruits (apple and pear) and vegetable (cucumber) samples in order to assess risk posed by the presence of such residues to the consumer. Triflumizole was applied at a recommended dose rate to apple and pear pulps and to a cucumber sample. The samples were collected at harvesting time following several treatments (three and/or four treatments). Triflumizole was extracted with methanol and re-extracted into dichloromethane. The presence of triflumizole was determined by HPLC with UV detection at 238 nm following the cleanup of the extract by open preparative chromatographic column with Florisil. The versatility of this method was evidenced by its excellent linearity (> 0.999) in the concentration range between 0.2 and 4.0 mg/kg. The mean recoveries evaluated from the untreated samples spiked at two different fortification levels. 0.1 and 0.4 mg/kg, and ranged from 87.5${\pm}$0.0 to 93.3${\pm}$2.6 for the tested fruits and vegetable, respectively, and the repeatability (as relative standard deviation) from three repetitive determinations of recoveries were no larger than 6%. The calculated limit of detection was 0.02 mg/kg and the minimum detectable level of 4 ng for triflumizole was easily detected. When triflumizole was sprayed onto the apple trees three times at 50-40-30 and 40-30-21 days prior to harvesting and four times onto the pear trees at 40-30-21-14 days prior to harvesting, the mean residual amounts of 0.05 and 0.06 mg/kg for apples and pears, respectively, were not detected in all of the treatments. When the cucumber sample was fumigated four times at 7, 5, 3 and 1 day prior to harvesting, the mean residual amount was not detectable. Triflumizole can be used safely when sprayed (wettable powder, 30% active ingredient) and fumigated (10%) 4 times at 14 and 1 day prior to harvesting to protect the fruits and vegetable, respectively.

• Research in Plant Disease
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• v.23 no.3
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• pp.268-277
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• 2017

Fusarium head bight (FHB) is a devastating disease on major cereal crops worldwide which causes primarily by Fusarium graminearum. Synthetic fungicides are generally used in conventional agriculture to control FHB. Their prolonged usage has led to environmental issues and human health problems. This has prompted interest in developing environmentally friendly biofungicides, including botanical fungicides. In this study, a total 100 plant extracts were tested for antifungal activity against F. graminearum. The crude extract of Pterocarpus santalinus heartwood showed the strongest antifungal activity and contained two antifungal metabolites which were identified as ${\alpha}$-cedrol and widdrol by GC-MS analysis. ${\alpha}$-Cedrol and widdrol isolated from P. santalinus heartwood extract had 31.25 mg/l and 125 mg/l of minimal inhibitory concentration against the spore germination of F. graminearum, and also showed broad spectrum antifungal activities against various plant pathogens. In addition, the wettable powder type formulation of heartwood extract of P. santalinus decreased FHB incidence in dose-dependent manner and suppressed the development of FHB with control values of 87.2% at 250-fold dilution, similar to that of chemical fungicide (92.6% at 2,000-fold dilution). This study suggests that the heartwood extract of P. santalinus could be used as an effective biofungicide for the control of FHB.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.51-57
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• 1987

The intent of this research is to acquire some basic informations about formulation of the viral pesticide, Hyphantria cunea nuclear polyhedrosis virus and its virulence under field condition. The nuclear polyhedrosis virus was formulated as wettable powder using spreader, sticker and U.V. protector. The formulated product and aqueous virus were diluted with water at the concentration of 1${\times}$106PIB/ml and sprayed on mulberry leaves in the field. The leaves were fed with 3rd instar larvae of H. cunea to determine the inactivation period of the viral pesticides. The aqueous virus was completely inactivated on 5th day after spray, while the formulated one showed a spare mortality to the larvae even on 20th day after spray. In field application test, The fromulated and aqueous virus were sprayed on individual mulberry tree and 3rd instar laevae of H. cunea were fed on the trees. The mortality of the larvae one day after spray of the formulated and aqueous virus were about 50% and 40%, respectively. The formulated virus exhibited a persistent virulence to the larvae up to 9th day after spray, which the mortality was approximately 30%. The residual virulence of the formulated and aqueous virus was extended up to 4th day and 2nd day after spray, respectively.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.227-233
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• 1987

Some derivatives of 3-(benzothiazol-2-yl)-1-methyl urea were synthesized by reaction of methyl isocyanate with 2-aminobenzothiazole derivatives prepared by thiocyanation of various substituted anilines. The compounds synthesized were identified by IR, NMR and mass spectra as 3-(5-methyl benzothiazol-2-yl)-1-methyl urea, 3-(5,6-dimethyl benzothiazol-2-yl)-1-methyl urea, 3-(6-ethyl benzothiazol-2-yl)-1-methyl urea, 3-(6-methoxy benzothiazol-2-yl)-1-methyl urea, 3-(6-chloro benzothiazol-2-yl)-1-methyl urea, and 3-(5, 6-dichloro benzothiazol-2-yl)-1-methyl urea. These compounds were subjected to the test for pre-emergence herbicidal activity in the pots with wettable powder formulation. All of these compounds showed pre-emergence herbicidal activity on the grasses (Digitaria adscendens HENR and Setaria viridis P. BEAUV) and broad-leaf weeds (Portulaca oleraces L. and Chenopodium album L.) at the dosage of 800g a.i. per 10a. Of the 6 compounds, 3-(6-ethyl benzothiazol-2-yl)-1-methyl urea showed the highest herbicidal effect on both the grasses and broad-leaf weeds. Even at the rate of 50g a.i. per 10a, this compound inhibited the growth of grasses, selectively.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.438-444
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• 2007

Bacillus licheniformis N1 is a biological control agent to control gray mold diseases caused by Botrytis cinerea. Various formulations of B. licheniformis N1 were generated and evaluated for the activity to control strawberry gray mold. The wettable powder type formulation N1E was selected in pot experiments with remarkable disease control activity on both strawberry leaves and flowers. The N1E formulation contained 400 g of com starch, 50 ml of olive oil, and 50 g of sucrose per a liter of bacterial fermentation culture. Optimum dilution of N1E to appropriately control the strawberry gray mold appeared to be 100-fold dilution in plastic house artificial infection experiments. The significant reduction of symptom development in the senescent leaves was apparent by the treatment of N1E at 100-fold dilution when N1E was applied before Bo. cinerea inoculation, but not after the inoculation. Both artificial infection experiments in a plastic house and natural infection experiments in the farm plastic house under production conditions revealed that the disease severity of gray mold on strawberry leaves and flowers was significantly reduced by N1E treatment. The disease control value of N1E on strawberry leaves was 81% under production conditions, as compared with the 61.5% conferred by a chemical fungicide, iprodione. This study suggests that our previously generated formulation of B. licheniformis N1 will be effective to control strawberry gray mold by its preventive activity.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.66-73
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• 2003

Actual pesticide usage in fruit vegetable cultivation was surveyed. Usage trend of in of vidual pesticides was evaluated to provide the data for the development of indicators of environmental impact and the production of safe agricultural products. The amount of the pesticides used for fruit vegetables was revealed in order of fungicide> insecticide> herbicide, showing that the portion of fungicide to the total amount used was about 70 to 80%. Main fungicides used on fruit vegetables were mancozeb, thiophanate-methyl propineb, etc while the insecticides were imidacloprid, milbemectin, methomyl, etc. Main formulation types of pesticide were wettable powder and emulsifiable concentrate. By different fruit vegetables and cultivation patterns, pesticide use per unit area was revealed red pepper (field cultivation, 13.2kg/ha), cucumber (field cultivation, 12.4kg/ha), sweet melon (field cultivation, 11.2kg/ha) as high pesticide use crops, meanwhile, water melon (greenhouse cultivation, 1.2kg/ha), sweet melon (greenhouse cultivation, 2.2kg/ha), strawberry (field cultivation, 2.8kg/ha) as low pesticide use crops.

• Research in Plant Disease
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• v.19 no.1
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• pp.45-48
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• 2013

Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. Rusts can affect a variety of plants. Development of new effective and environmentally benign agents against rusts is of great interest. In this study, we investigated the disease control efficacy of the emulsion concentrate (EC10) and wettable powder (WP20) type formulations of the extract of Magnolia officinalis (Magjia90; containing honokiol and magnolol at 90%) against rust diseases of perilla and zoysiagrass in fields. The treatment of EC10 and WP20 of Magjia90 showed control values of 47.9% to 69.6% and Magjia90-WP20 reduced more effectively the development of rust symptoms on perilla plants than Magjia90-EC10. Magjia90-WP20 also highly suppressed zoysiagrass rust with control values of 65.7% to 80.5%. On the other hand, no harmful effect of Magjia90-EC10 and Magjia90-WP20 was observed on the perilla and zoysiagrass plants tested. The results strongly indicate that the extract of M. officinalis (Magjia90) can be used as a natural fungicide for the control of rust diseases.

• Research in Plant Disease
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• v.17 no.1
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• pp.25-31
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• 2011

Rust causes significant losses in the yield and quality of various crops. The development of new effective and environmentally benign agents against the pathogen is of great interest. In the course of searching a natural antifungal compound from medicinal plants, we found that the methanol extract of Angelica gigas roots had a potent control efficacy against wheat leaf rust (WLR) caused by Puccinia recondita. The antifungal substance was isolated from the methanol extract by silica gel column chromatography, alumina column chromatography and $C_{18}$ preparative HPLC. It was identified as decursinol angelate by EI-MS and $^1H$-NMR data. In in vivo test, decursinol angelate effectively suppressed the development of WLR and red pepper anthracnose (RPA) among the 6 plant diseases tested. In addition, the wettable powder-type formulation of ethyl acetate extract of A. gigas roots significantly suppressed the development of WLR. The crude extract containing decursinol angelate and the chemical appear to be a potential candidate for control of WLR. In addition, this is the first report on the in vivo antifungal activity of decursinol angelate against WLR as well as RPA.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.234-240
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• 1988

Some chloroacetamide derivatives were synthesized from 2,6-dialkyl, aniline 4-chloroaniline, or 3,4-dichloroaniline with alkyl 2-bromopropionate and chloroacetyl chloride and identified by elemental analyses, NMR, and GC/MS spectra as N-(1'-methoxycarbonylethyl)-N-chloroacetyl-2,6-dimethylaniline(ACRI-S-8609), etc. These compounds synthesized were subjected to the test for pre-emergence herbicidal effecs on some grass weeds(Digitaria adscendens, Setaria viridis, Echinochloa crus-galli) and broad leaf weeds(Portulaca oleracea, Amaranthus lividus, Chenopodium album) in pots applied as wettable powder formulations. It was found that N-(1'-ethoxycarbonylethyl)-N-chloroacetyl-2,6-dimethylaniline(ACRI-S-8701) has the highest herbicidal effect on grass weeds, which corresponds to a 95% control effect at an application of 200g a.i/10a. Whereas, some chloroacetamide derivatives derived from 4-chloroaniline or 3,4-dichloroaniline had very weak herbicidal effects on grass and broad leaf weeds.

• Research in Plant Disease
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• v.20 no.3
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• pp.196-200
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• 2014

This study was carried out to determine the effect of mixing with paraffin oil on rainfastness of mancozeb on citrus fruits and assay the improvement of control effect of mancozeb against citrus melanose by mixing with paraffin oil. In artificial rainfall condition (7.2 mm/hr), the attached contents of mancozeb on detached fruits were the most in treatment of mancozeb 0.2% + paraffin oil 0.1% as the contents was $7.43{\mu}g/cm^2$ after treatment of rainfall for 10 hr. In open field condition, the contents of attached mancozeb on fruits were significantly more in treatment of mancozeb 0.2% + paraffin oil 0.1% or 0.25% than the other treatments 1, 15 and 25 days after treatment 2009 and 2010 seasons. The disease incidence was significantly lower in treatment of mancozeb 0.2% + paraffin oil 0.1% or 0.25% than treatment of mancozeb 0.2% only 2009, 2010 and 2011 seasons. Based on this study, it was suggested that the control effect of mancozeb against citrus melanose can be improved by mixing with paraffin oil.