• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.328-335
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• 2015

BACKGROUND: The present investigation was aimed to predict the pre-harvest residue limits (PHRLs) of the fluopicolide and metrafenone on cherry tomato and to estimate their half-life and characteristics of the residues.METHODS AND RESULTS: Pesticides were treated once on cherry tomato in field 1 and 2 under the standard application rate. The samples were collected 7 times at the end of 0(2 hours after pesticides spaying), 1, 2, 3, 5, 7 and 10 days before harvest. Residues of fluopicolide and metrafenone were analyzed by the LC-MS/MS. In this study, the method limit of quantification (MLOQ) for both fluopicolide and metrafenone in cherry tomato was found to be 0.005 mg kg-1. Their recovery levels were 92.7∼94.8% and 82.6∼88.0%, shown with coefficient of variation of less than 10%. Half-life of fluopicolide and metrafenone in field 1 and 2 were found to be 15.0 days and 12.8 days, 18.9 days and 21.5 days, respectively.CONCLUSION: Based on the results, this study shows the level of PHRL on cherry tomato is 0.27 mg/kg for fluopicolide and 2.29 mg/kg for metrafenone at 10 days before harvesting. The present study indicates the residues of both pesticides on cherry tomato will be below maximum residue limit (MRL) at harvest.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.50-56
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• 2017

BACKGROUND: The present study was carried out to identify the residue patterns of insecticide pyridalyl and fungicide fluopicolide in watermelon and calculate the biological half-lives for establishing the pre-harvest residue limits (PHRLs). METHODSANDRESULTS:The watermelon samples for residue analysis were harvested 7 times during 0~10 days (Field 1) and 0~20 days (Field 2) after treatment of pesticides on watermelon in two different fields at the recommended dose, respectively. The residue analysis was conducted with HPLC/UVD. The method limit of quantitation (MLOQ) were set at 0.05 and 0.02 mg/kg, respectively, and overall mean recoveries were 81.2~90.5% for pyridalyl and fluopicolide. The residues in sample were stable for 43~47 days. The initial residue amount in field 1 and 2 were 0.12~0.16 mg/kg for pyridalyl and 0.23~0.24 mg/kg for fluopicolide, which were below maximum residue limit (MRL). The biological half-lives in field 1 and 2 were 26.9 and 17.9 days for pyridalyl and 16.6 and 94.2 days for fluopicolide, respectively. CONCLUSION: The PHRL for watermelon were estimated as 0.21 and 1.03 mg/kg for pyridalyl and flopicolide at 10 days before harvesting. The residue patterns of pyridalyl and fluopicolide were characterized by a very slow decrease of residue levels in watermelon.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.361-369
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• 2015

This study investigated residual characteristics of bistrifluron and fluopicolide in Korean cabbage, and suggested the pre-harvest residue limits (PHRLs) based on their dissipation patterns and biological half-lives. The pesticides were sprayed on Korean cabbage in two different region under greenhouse conditions at the recommended dose, respectively. The samples for residue analysis were harvested at 0 (2 hr), 1, 2, 4, 6, 8 and 10 days after treatment, and analyzed by HPLC after clean-up with Florisil SPE. The limit of quantification (LOQ) was $0.03mg\;kg^{-1}$ for bistrifluron and fluopicolide, and the recoveries ranged from 87.2-110.6% with below 5% of RSD. The biological half-lives of field I and field II were 3.9 and 4.2 days for bistrifluron and 4.9 and 4.2 days for fluopicolide, respectively. The PHRL of bistrifluron and fluopicolide were recommended as 3.83 and $3.23mg\;kg^{-1}$ for 10 days before harvest, respectively.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.367-371
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• 2010

In this study, we evaluated the efficacy of fluopicolide to inhibit Phytophthora capsici in vitro, and to control pepper Phytophthora blight in a greenhouse and pepper fields. Fluopicolide was tested on various developmental stages of P. capsici 06-143 (a sensitive isolate to metalaxyl) and JHAW1-2 (a resistant isolate to metalaxyl). Mycelial growth and zoosporangium germination of both isolates were completely inhibited at $4.0\;{\mu}g/ml$ of the fungicide in vitro. The $EC_{50}$ (effective concentrations reducing 50%) of P. capsici 06-143 against zoospore were $0.219\;{\mu}g/ml$, while those of JHAW1-2 were $3.829\;{\mu}g/ml$. When fluopicolide was applied at 100 and $1,000\;{\mu}g/ml$ 7 days before inoculation with P. capsici 06-143 in the greenhouse test, the disease was controlled completely until 6 days after inoculation. However, the curative effect of fluopicolide was not as much as the protective effect. When fluopicolide was applied by both soil drenching and foliar spraying, the treatments strongly protected pepper against the Phytophthora blight disease. Based on these results, fluopicolide can be a promising candidate for a fungicide to control P. capsici in the pepper fields.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.452-458
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• 2020

In this study we aimed to find out pesticide types with probability for underestimation of dietary exposure to pesticide residues in Korea by comparing the residue definitions between Korea and Codex standards. In addition, we sought to establish priorities regarding the necessity of review concerning pesticide types and their impacts based on the risk assessment and dietary exposure underestimation. As a result, we found that according to the residue definition information, 44 pesticides have probability for underestimation in terms of dietary exposure assessments. Among them, 24 pesticides have priority for review of dietary exposure underestimation and its impacts on risk assessment, based on the ADI values of pesticides, Korean MRL information and toxicological information of metabolite. The 24 pesticides were as follows: acibensolar-S-methyl, chlorfenapyr, chlorothalonil, cyantraniliprole, cyclaniliprole, cyflumetofen, dithiocarbamates, fenamidone, fenpyroximate, fluazifop-P-butyl, fluopicolide, flupyradifuron, fluxapyroxad, glyphosate, hexythiazox, isoprothiolane, isopyrazam, myclobutanil, penthiopyrad, propiconazole, spinetoram, spiromesifen, spirotetramat, trifloxystrobin. Furthermore, chlorfenapyr, chlorothalonil, dithiocarbamates and fenamidone may have considered a top priority for review due to greater toxicity of metabolite. This study could be of great use for improvement on risk assessment approaches in South Korea regarding pesticide residues in food commodities.

• Research in Plant Disease
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• v.22 no.3
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• pp.208-212
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• 2016

During the nursery seedlings stage at Muan in 2013, moisture and temperature conditions were favorable for the occurrence of onion downy mildew. Several fungicides were evaluated for controlling onion downy mildew at the stage of seedling. The disease incidence of the untreated control was 51.1%, which was sufficient to evaluate the fungicide efficacy for the control of onion downy mildew. Incidence at the mancozeb treatment (MAN treatment) was 4.4% and it was the highest control value of 91.4%. Incidence at the various fungicides treatment (MIX treatment) consisted of amectotradin plus dimethomorph, floupicolide plus propamocarb HCl, or dimethomorph plus pyraclostrobin was 10.0%, and the control value of the MIX treatment was 80.4%. Among the tested fungicides, amectotradin plus dimethomorph (AME plus DIM treatment) was selected and treated. Incidence of AME plus DIM treatment was 12.2%. There was statistically significant difference among the three different treatments and the untreated control. These results suggest that the application of fungicides on onion nursery seedlings was effective to control the onion downy mildew.