• The Plant Pathology Journal
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• v.35 no.1
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• pp.71-76
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• 2019

$SdhB^{P225F}$ and $SdhB^{H272R}$ mutations have been found associated with boscalid resistance in Botrytis cinerea from strawberry in Shanghai, China. For rapid detection of two mutations, tetra-primers were designed and optimized to gain the relatively high accuracy and specificity based on the ARMS-PCR technique, by which resistance can be identified with different lengths of products on agarose gels. The tetra-primer ARMS-PCR systems for $SdhB^{P225F}$ and $SdhB^{H272R}$ were validated by 9 SdhB-squenced strains repeatedly. Then, sensitivity of 30 more strains were also tested by the methods, which were accordant with genotypes by sequencing and the sensitivity of conidial germination to boscalid by 100%. Thus, the methods developed in this study are proved to be rapid, inexpensive, accurate and practical for resistance detection of Botrytis cinerea caused by $SdhB^{P225F}$ and $SdhB^{H272R}$ mutations.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.53-60
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• 2014

This study was conducted to investigate the changes of the residual amount in the leafstalk (end) and the fore-end (upper) portion of lettuce leaves during cultivation period to 14 days, 12 times in total (0, 1, 2, 3, 4, 5, 7, 8, 10, 12, 13 and 14 days) after spraying with boscalid and lufenuron. In the case of boscalid, the initial concentrations at 3 hours (0 day) of the leafstalk and the fore-end portion of lettuce leaves were 18.26 mg/kg and 84.97 mg/kg, respectively and the residual amounts were rapidly decreased to 0.31 mg/kg and 0.37 mg/kg at 14 days after chemical application. In the case of lufenuron, the initial concentrations at 3 hours (0 day) of the leafstalk and the fore-end portion of lettuce leaves were 0.91 mg/kg and 5.21 mg/kg, respectively and the residual amounts were rapidly decreased to 0.06 mg/kg and 0.09 mg/kg at 13 days after chemical application. The variations of the residual concentrations analyzing 12 times after spraying showed that the residual amounts of the leafstalk portion of lettuce leaves were less than its fore-end portion in boscalid and lufenuron. In additon, 9 kinds of pesticide including boscalid in 16 lettuce leaf (found to contain pesticide in 2013) showed that the residual amounts of the leafstalk portion of lettuce leaves were less than its fore-end portion as well.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.269-277
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• 2011

Recent outbreak of new diseases and pests which were introduced from abroad, seriously hampered both quality and safety of paprika fruits. This study has been carried out to aid an establishment of guideline for safe use of pesticides and reduction of their residues on paprika. Systemic fungicides boscalid and pyraclostrobin of either mixed (a.i.; 13.6+6.8%) or single (a.i.; 47 and 18.8%, respectively) water dispersible granule formulation(WG) products were sprayed with recommended or double dosage on paprika grown in green house at March and June. To draw pre-harvest residue limit, residues of each fungicide were analyzed from fruits collected eight times from 18 to 1 day pre-harvest. The biological half-lives of both boscalid and pyraclostrobin in mixed formulation in March and June were slightly shorter than those of single formulation which ranged from 14.4 to 20.1 days. Residue levels of both fungicides of single formulation in fruits in June were about one lower compared to those in March. However, application of double dosage frequently exceeded MRLs from fruits grown both seasons. These results showed that residue levels on fruits persisted longer period of time, more than two weeks, and so the case applied in winter season. The dissipation of fungicides on leaves and fruits was compared. The distribution of both fungicides in leaves was 20-200 times higher than that of fruits and persisted up to 18 days of pre-harvest period at the concentration of 10-40 ${\mu}g\;g^{-1}$. This study indicated that the mixed formulation product exhibited low residues in fruits, but high and long enough to pathogen growth in leaves.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.96-101
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• 2012

Dollar spot caused by Sclerotinia homoeocarpa F.T. Benn. is a common and economically important turfgrass disease in South Korea. Fungicides were evaluated for control of dollar spot in creeping bentgrass golf course putting green. Commercial formulations of propiconazole, thiophanate-methyl, chlorothalonil, trifloxystrobin and boscalid were applied to plots of creeping bentgrass, each of the latter four fungicides was tank mixed with propiconazole at the same rates, and applied as treatments. The dollar spot severity in the nontreated plots of field A and B progressed toward peak diseases of 18.3 and 66.7% from 10 or 15 days after inoculation, respectively. Significant differences were detected among control values of the fungicides. Dollar spot control provided by boscalid was significantly greater than the other fungicides which showed low control values in a higher disease condition. No synergistic interactions, except propiconazole + thiophanate-methyl treated plot, were detected under a lower disease pressure. However, under a higher disease pressure, synergism was observed at all fungicide combinations, except a propiconazole and boscalid tank mixture. These data suggest turfgrass managers in golf course can take advantage of fungicide synergism to control dollar spot using the products and rates in this study.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.170-175
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• 2010

A total of 24 isolates of S. homoeocarpa were isolated from 16 golf courses in Korea. Chemical resistance of 24 isolates was determined by in vitro fungal growth on fungicide-amended media with thiophanatemethyl (Benzimidazole fungicide family), tebuconazole (demethylation inhibitor fungicide family: DMI), and iprodione (dicarboximide fungicide family). Results indicated that 83.3% of 24 isolates were resistant to iprodione, 62.5% resistant to thiophanate-methyl and 0% resistant to tebuconazale. The dual resistance of iprodione and thiophanate-methyl was 58.3.%. Occurrence rate of fungicide resistance of thiophanate-methyl and iprodione had no relation to turfgrass varieties and isolated locations of pathogen. In the filed test, procymidone, boscalid, and fluquinconazole+pyrimethanil effectively controlled the dollar spot of creeping bentgrass.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.128-133
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• 2024

Using the freezing removal method, we investigated residual pesticides in 50 grape seed oils distributed in Gyeonggi Province, South Korea. The fat was mixed with acetonitrile and then frozen at ≤-20℃ for 24 h. Fats and oils were removed by separating those in solid state and the extract acetonitrile in liquid state. Ten residual pesticides were detected 161 times in 49 of 50 cases. The detected pesticides were boscalid, cyclufenamide, deltamethrin, difenoconazole, fluxapyroxad, fenpyrazamine, kresoxim-methyl, piperonyl butoxide, tebuconazole, and trifluoxysorbin. Boscalid, a fungicide, was most frequently detected (44 times), followed by fluxapiroxad (35 times). The detection range was 0.01-1.10 mg/kg, which was within the legal limit of residual pesticide for grapes. The recovery rate of the detected pesticides was 72.6-129.8% and the ratio of estimated daily intake/acceptable daily intake was calculated to determine the risk of the detected pesticides, which was <0.0028%. This indicated that the risk caused by pesticide residues in grape seed oil is at a safe level.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.447-452
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• 2008

Four hundred and sixty six isolates of B. cinerea were obtained from infected leaves, stems and fruits of paprika grown in greenhouses or plastic film houses in Gangwon province, Korea, between August and November in 2006 and 2007. These isolates were classified into five representative phenotypes of resistant (R) and sensitive (S) reactions as SSR, SRR, RSS, RRS and RSR according to the responses of isolates against benzimidazole, dicarboximide and N-phenyl-carbamate fungicide in order. The percentage of five phenotypes were 51.3, 2.4, 35.6, 8.1 and 2.6%, respectively. The SSR phenotype (51.3%) was the most common. Among the nineteen fungicide products evaluated to compare their efficacy against gray mold pathogen on the paprika fruit inoculated with fungal mycelia, the mixture of diethofencarb and carbendazim was the most effective followed by iprodione, boscalid, the mixture of iprodione and thiophanate-methyl, fludioxonil, polyoxin-B, fluazinam, the mixture of tebuconazole and tolyfluanid and procymidone; while in the assay methods inoculated with fungal spores, the mixture of tebuconazole and tolyfluanid was the most effective in controlling gray mold followed by boscalid, fludioxonil, the mixture of diethofencarb and carbendazim and the mixture of pyrimethanil and chlorothalonil.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.69-79
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• 2022

The purpose of this study is to monitor the pesticide residues in frozen fruits and vegetables distributed and sold in online and offline markets in Korea. For the study, 107 samples of 34 types of frozen fruits and vegetables were examined, and a total of 341 pesticide residues were analyzed by using multiclass pesticide multi-residue methods of the Korean Food Code. As a result, pesticide residues were detected from 16 of 64 frozen fruits samples and 15 of 43 frozen vegetables samples. Conclusively, residues were detected from 31 samples in total, showing a detection rate of 29.0%. Specifically, pyridaben exceeded the Maximum Residue Limits (MRLs) based on the Positive list system (PLS) in one of the frozen radish leaves, and the violation rate was 0.9%. Detection on frozen fruits and vegetables was made 23 times for 11 types and 36 times for 21 types. In total, 28 types of pesticide residues were detected 59 times. Fungicides were detected the most in frozen fruits, while insecticides were detected the most in frozen vegetables. The most detected pesticides were the insecticide, acaricide chlorfenapyr (5) and the fungicide boscalid (5). Chlorfenapyr was detected only in frozen vegetables, and boscalid was detected in frozen fruits except one.

• Analytical Science and Technology
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• v.37 no.1
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• pp.1-11
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• 2024

In agricultural households cultivating vegetables and fruits, the use of various pesticides to protect crops from diseases and pests or to control weeds is widely practiced enhancing quality and productivity. However, pesticides can pose a threat to consumer health by remaining on the food surface or migrating into the food interior. Households commonly peel off skins, wash with water, or use chemical methods to remove foreign substances including residual pesticides on the food surface. In this study, we measured the washing rate by comparing the pesticide concentrations before and after washing in the leafy vegetable perilla leaves and the fruits strawberries and apples, which were intentionally exposed to pesticides. We compared washing rates using tap water, a baking soda solution, and a commercially available food-specific cleaning solution. The target pesticides for analysis were azoxystrobin, bifenthrin, boscalid, difenoconazole, flubendiamide, and indoxacarb, and the residual pesticide analysis was performed using GC-MS/MS or LC-MS/MS. The removal rates of pesticides were highest with the food-specific cleaner, followed by baking soda and tap water in order.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.283-289
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• 2019

This study was performed to monitor the residual pesticides in agricultural products used in school foodservice in the Gwangju metropolitan area. Risk assessment was also carried out based on the amount of agricultural products consumed. A total of 320 agricultural products supplied to schools in Gwangju were analyzed from 2015 to 2017. The pre-treatment and residual pesticide analysis of these products was conducted in accordance with the second method for multi-residue analysis of pesticides in the Korean food code. The hazard index was calculated by dividing the estimated daily intake (EDI) of pesticides by the acceptable daily intake (ADI). The linearity correlation coefficient for the calibration curve was 0.9923 to 1.0000, LOD 0.004 to 0.019 mg/kg, LOQ 0.012 to 0.057 mg/kg, and recovery was 79.1 to 100.2%. Residual pesticides were detected in 18 (5.6%) of 320 agricultural products used for school foodservice, and one sample of sweet potato stem (0.3%) exceeded the maximum residual limit (MRL). The detection frequency for chili peppers and bell peppers was higher than that for other agricultural products. The frequently-detected pesticides were boscalid and acetamiprid. These results showed that residual pesticide management is needed for chili pepper, bell pepper and sweet potato stem among agricultural products supplied to schools. The hazard index of bifenthrin in sweet potato stem showed the highest (64.18%), and the other pesticides were 0.03-8.23%. These results indicated that agricultural products supplied to schools in Gwangju were safe for consumption. To minimize the intake of residual pesticides, it is necessary to not only thoroughly wash agricultural products but to also ensure the expanded supply of products that are pesticide-free.