• Korean Journal of Environmental Agriculture
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• v.3 no.2
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• pp.1-8
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• 1984

The present study was performed to elucidate pesticide residues in paddy rice applied with different application schedules and frequencies of pesticide formulations. Pungsanbyeo($Japonica{\times}Indica hybrid$) of rice(Oryza sativa L.) was chosen as target crop. Isoprothiolane(diisopropyl-l,3-dithiolan-2-ylidene malonate) 40EC (emulsifiable concentrates), 12G (granular), and chlorpyriphosmethyl [0,0-dimethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate] 25EC, 3G were selected as pesticide formulations. The closer the isoprothiolane EC application to harvest, the higher the residues in rice straw retained at harvest; however the G application on 30 days before harvest resulted in highest residue. Chlorpyriphosmethyl residues were higher as it was applied nearby to harvest. Degradation rate of chlorpyriphos-methyl in husked rice was quite similar to in rice straw, on the other hand isoprothiolane in the rice was more stable than that in rice straw. Translocated amount of applied G formulation to husked rice was meager irrespective to the chemicals. Percent reduction of isoprothiolane residues in husked rice by polishing was not related to application frequencies but to application date before harvest. Residual portions in rice straw, husked rice and polished rice of total input amount during rice cultivation were ranged from 0.19% to 0.99%, 0.01% to 0.48%, and 0.15%, respectively.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.134-139
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• 2011

To investigate an amount of pesticide residue in rice paddy field soils and greenhouse soil, this monitoring was carried out pesticide detection frequency and concentrations collected samples from 150 rice paddy field soils and 152 greenhouse soils of nationwide in the year of 2007, and 2008, respectively. The detection limit of pesticides of this experiment were ranged 0.001~0.005 ppm. In 2007, One hundred fifty samples were collected from rice paddy field soils in April and monitored for 120 wide-used pesticides. A total of 11 pesticides were detected four fungicides, four insecticides and three herbicides in paddy field soils. The highest concentration levels of pesticide detected were 0.84 ppm as herbicide oxadiazon, 0.81 ppm as fungicide isoprothiolane and 0.50 ppm as insecticide buprofezin. The detection frequencies range were 0~19.3%, and the frequency was 2.7% as isoprothiolane and 19.3% as oxadiazon in paddy field soils. In 2008, One hundred fifty two samples were collected from greenhouse soils in April and monitored for 120 wide-used pesticides. A total of 29 pesticides were detected six fungicides, sixteen insecticides and seven herbicides in greenhouse soils. high concentration levels of pesticide detected levels were 5.09 ppm as insecticide chlorfenapyr, 2.57 ppm as fungicide chlorothalonil and 0.72 ppm as herbicide oxadiazon. The detection frequencies range were 0~38.8%, and high frequencies were 38.8% as insecticide endosulfan, 13.2% as oxadiazone, 10.5% as fungicide hexaconazole and 7.2% as isoprothiolane in greenhouse soils, Total endosulfan and oxadiazon were showed high detection frequency of 38.8% and 13.2%, respectively.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.133-139
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• 2013

To investigate the sensitivity of Sclerotium cepivorum causing garlic white rot to 5 fungicides, including prochloraz, tebuconazole, flutolanil, iminoctadine and isoprothiolane, 147 isolates isolated from infected garlics from 2008 to 2009 through a single sclerotium isolation were screened. While each mean value of $EC_{50}$ (effective concentration reducing mycelial growth by 50%) of S. cepivorum isolates collected in 2008 to each fungicide was 0.054, 0.012, 23.189, 0.901, and $21.362{\mu}g\;mL^{-1}$, that of 2009 isolates were 0.030, 0.020, 10.367, 1.684, $33.406{\mu}g\;mL^{-1}$. There was a difference in mean value of $EC_{50}$ of S. cepivorum according to regions isolated. $EC_{50}$ values of S. cepivorum isolated in Goheung to flutolanil and isoprothiolane were 14.468 and $24.653{\mu}g\;mL^{-1}$, respectively, which was lower than those of Seosan and Taeahn. Isolates from Taeahn showed the lowest $EC_{50}$ value to prochloraz as $0.008{\mu}g\;mL^{-1}$. In addition, we could not find any resistant isolates to fungicides tested. The $EC_{50}$ values in this study will be used in a fungicide resistance monitoring program to determine whether shifts in sensitivity to fungicides included into different groups are occurring in S. cepivorum populations.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.61.1-61.1
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• 2008

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.45-51
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• 1984

This study was performed to evaluate the aquatoxicity of 5 chemicals (butachlor, isoprothiolane, probenazole, carbofuran, and cartap) to carp (Cyprinus carpio), discuss the impact on the $96 hr-LC_{50}$ values of the chemicals with the exposure time. In butachlor, we also compared the acute toxicity values between two exposure system, the continuous flow system and static state system, and measured the dissolved oxygen concentrations in the two systems. The acute toxicity values (96 hr-LC50 values) of the 5 chemicals were 0.25 ppm in butachlor, 10.0 ppm in isoprothiolane, 6.2 ppm in probenazole, 1.40 ppm in carbofuran, and 0.64 ppm in cartap, respectively. We also found that the $LC_{50}$ values were downed with increase of the exposure time.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.31-35
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• 2013

In this study, the pesticide residues of polished rice and brown rice were measured after washing and cooking process. The initial concentrations of isoprothiolane and fthalide were $7.134{\pm}0.03mg/kg$ and $2.024{\pm}0.04mg/kg$ for polished rice, and $17.941{\pm}1.41mg/kg$ and $6.413{\pm}0.19mg/kg$ for brown rice, respectively. After first washing process, the removal rates of isoprothiolane were 23.0% (polished rice) and 18.5% (brown rice). Also, the case of fthalide, the removal rates were 14.0% and 9.7%, respectively. The removal dose was increased, but the removal rate was decreased in proportion to the number of washing process, After the cooking process, the removal rates of isoprothiolane and fthalide were 66.0% and 79.0% (polished rice), and 88.7% and 92.9% (brown rice), respectively. The removal rate of isoprothiolane was higher in the washing process, and the case of fthalide was higher in the cooking process. The optimum washing process for the pesticides removal was five times and the cooking process was the most effective to use the new water after soaking the rice in water during 30 minutes.

• Korean Journal of Environmental Agriculture
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• v.14 no.2
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• pp.163-170
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• 1995

This study was carried out to compare the acute toxicity(96hr) of 13 chemicals to carp (Cyprinus carpio L.) and israeli carp (Cyprinus israeli carpio L.) and the activities of acetylcholinesterase (AchE) and glutathione S-transferase (GST) in israeli carp exposed to five insecticides (diazinon, malathion, carbofuran, cartap, methomyl). $LC_{50}$ values of acute toxicity of the chemicals to israeli carp were endosulfan 0.0061ppm, captafol 0.041ppm, chlorothalonil 0.073ppm, butachlor 0.48ppm, captan 0.14ppm, carbofuran 1.13ppm, cartap 1.15ppm, diazinon 1.35ppm, nitrofen 3.72ppm, methomyl 4.39ppm, propanil 10.61ppm, malathion 11.78ppm and isoprothiolane 12.81ppm. The acute toxicity of endosulfan 0.0061ppm was 2100 times higher than that of isoprothiolane 12.81ppm. $LC_{50}$ values of acute toxicity of the chemicals to carp were endosulfan 0.0026ppm, captafol 0.062ppm, chlorothalonil 0.078ppm, captan 0.14ppm, and butachlor 0.47ppm, carbofuran 0.52ppm, nitrofen 0.58ppm, diazinon 0.81ppm, cartap 0.82ppm, methomyl 5.03ppm, propanil 10.67ppm, malathion 11.92ppm, and isoprothiolane 13.20ppm. The acute toxicity of endosulfan was 5,000 times higher than that of isoprothiolane. The toxicity of diazinon, carbofuran, cartap, endosulfan, and nitrofen to carp was approximately 2-6 times as high as that to israeli carp, but the toxicity of malathion, methomyl and captafol to israeli carp was slightly higher than that to carp. AchE activity was inhibited by 31% and 52% after 96hr’s exposure of israeli carp to diazinon and malathion respectively. GST activity in israeli carp was significantly induced by methomyl exposure for 96 hr.

• Research in Plant Disease
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• v.10 no.1
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• pp.69-72
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• 2004

The control activity of isoprothiolane and tricyclazole mixed with carbosulfan, and probenazole by the nursery treatment was performed against rice leaf and neck blast caused by Magnaporthe grisea. In the paddy field, three fungicides showed good activities against leaf blast 3 months after nursery treatment. Especially the activity of tricyclazole against leaf blast gradually increased by the laps of time to 85.5％, which was assessed at 6 September,2003. Although the control value of isoprotholane and tricyclazole mixed with carbosulfan against neck blast was 47.5％ and 61.1％, respectively, probenazole showed a very high activity against not only leaf blast but also neck blast, of which that was 91.2％. No phytotoxicity was observed in all the treatments after transplanting rice seedling in the paddy field. Based on these results, three systemic fungicides tested in this study showed such a good potential that they might be used to formulate the nursery treating granule.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.328-333
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• 1983

Due to fast industrialization and reduced agricultural population, there has been increased farm mechanization to reduce the labor requirement. In rice production, mechanical transplanting has been increasingly popular due to the heavy labor requirement in hand transplanting and development of convenient transplanters. For mechanical transplanting, rice seedlings is grown in boxes with limited soils under super dense population, thus short period of exposure to unfavorable temperature and poor water management would cause severe damage to rice seedlings such as seedling damping off and the similar physiological disorders. Several chemicals were evaluated for their effectiveness to control the disease and disorders, and other effects as plant growth stimulants. 3-hydroxy-5-methylisoxazole-a soil fungicide, Metalozyl-a fungicide which controls mildew, SF 8002-the composite of above two chemicals, and Isoprothiolane-a fungicide which controls rice blast were found to be effective controling seedling damping off and similar physiological disorders, and improvement of physiological characteristics of the seedlings such as the amount of bleeding sap, rooting ability, negative geotrophism, and regrowth after cutting. The results indicated that the chemicals will be very effective raising healthy seedlings even under unfavorable environments by the improvement of physiological activities of seedlings and preventing seedling damping off and the similar physiological disorders.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.222-228
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• 2008

Algal Growth-inhibition tests were conducted with 6 pesticides butachlor GR (5%), butachlor EW (33%), isoprothiolane GR (12%), isoprothiolane EC (40%), diazinon GR (3%) and diazinon EC (34%) to determine their comparative toxicity to three species of freshwater green algae Selenastrum capricornutum, Scenedesmus subspicatus, Chlorella vulgris and one species diatom Nitzschia palea. The test species were exposed to the test pesticide for 72 hours and the toxicity represented $EC_{50}$ value calculated by the reduction in growth rate at 72 hours. The toxicity of EC or EW formulation to green algae and diatom was higher than the toxicity of GR formulation at all test in this study. Also, the toxicity of EC formulation was higher than the toxicity technical pesticide. These results indicate that the types of pesticide formulation may affect on their toxicity on algae and the green alga, S. capricornutum and S. subspicatus were more sensitive than C. vulgris. Also, the sensitivity of the diatom, N. palea showed equal or lower than S. capricornutum, S. subspicatus but more sensitive than C. vulgris.