• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.21-27
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• 2023

Pre-harvest residue limits (PHRLs) have been proposed as criteria for a proactive role to exceed the maximum residue limit (MRL) of pesticides in agricultural products at harvest. However, PHRL numbers are significantly less than those of established MRLs. This study was performed to determine the dissipation constants and residual concentrations of lufenuron after application on crown daisy and chamnamul under green house conditions. Two residue field trials for each crown daisy and chamnamul were selected to consider a different geographical site at least 20 km far from one another. The pesticide was treated according to critical GAP. After samples were sprayed with lufenuron, they were collected at 0, 1, 3, 5, 7, 10, and 14 days and analyzed using HPLC-DAD. The mean recoveries of crown daisy and chamnamul were within the range of 70-120% with below 20% coefficient variation, which is within the acceptable limits specified by the manual of pre-harvest residue study for pesticides (MFDS, 2014). The biological half-lives in field I and field II were 7.0 and 4.6 days for crown daisy and 2.7 and 2.8 days for chamnamul, respectively. The lower bounds of 95% confidence intervals of dissipation rate constants of lufenuron in crown daisy were determined to be 0.0692 and 0.1298 for field I and field II, respectively, and in chamnamul were 0.2067 for both field I and field II. After applying lufenuron 5% EC, the lufenuron residues on crown daisy and chamnamul at the pre-harvest intervals (14 days for crown daisy and 7 days for chamnamul) were below the safe levels. The dissipation rates of lufenuron in crown daisy and chamnamul were evaluated for similarities with leafy vegetables based on a 95% confidence interval.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.317-322
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• 2016

A pesticide mix solution containing difenoconazole, lambda-cyhalothrin, and lufenuron was applied 3 times on field grown chili pepper at a fivefold overdose dilution concentration of the spray solution at a pre-harvest interval of 7 day. Difenoconazole, lambda-cyhalothrin, and lufenuron were detected at 4.43, 0.334, and 1.56 mg/kg, respectively, in raw chili pepper. Washing with water reduced the residue levels to 91.4, 94.3, and 85.3%, respectively. In dried chili pepper, the residues of difenoconazole, lambda-cyhalothrin, and lufenuron were 22.2 mg/kg (processing factor, Pf =5.01), 1.65 mg/kg (Pf =4.94), and 6.54 mg/kg (Pf =4.19). In the seeds, difenoconazole and lambda-cyhalothrin were not detected, and lufenuron was detected at 0.0075 mg/kg (n=1) and <0.005 mg/kg (n=2). Thus the pesticide residues in the seeds was negligible. In the seed oil, difenoconazole and lufenuron residues were 0.0263 and 0.0295 mg/kg, respectively (concentration factors=5.26 and 4.72). These concentration factors supported the theoretical concentration factor of 6.8, assuming that all of compound present in the seed are transferred into the oil.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.42-48
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• 2017

This study was conducted to compare the effect of bagging technique on the presence of pesticide residues in various parts of grape fruit (whole fruit, pulp and peel). The tested pesticides were diluted at 2,000 times and sprayed three times onto the crops at an interval of seven days and then they were collected at 0, 1, 3, 5 and 7 days after final application. Later, bagging/non-bagging samples were pre-treated with fruit, pulp and peel samples, respectively. Thiacloprid and lufenuron were not detected in any of the bagging samples. The thiacloprid residues of non-bagging samples in whole, peel and pulp samples were 0.47-1.09, 0.18-0.33 and 1.24-1.67 mg/kg, respectively. The lufenuron residues of non-bagging samples in whole fruit, peel and pulp samples were 0.16-0.62, < LOD-0.08 and 0.85-1.48 mg/kg, respectively. The biological half-lives of thiacloprid and lufenuron in whole fruit, peel and pulp of non-bagging samples were 5.7, 15.1 and 7.8 days and 4.0, 9.4 and 2.6 days, respectively. While the unbagged samples showed a sequential decrease in pesticide residues, this study concludes that bagging would be an effective method to protect the presence of thiacloprid and lufenuron residues in grape fruits.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.34-42
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• 2008

In order to know the residual pattern of some pesticides and predict to the degradation period until below MRL, we experimented chlorothalonil, indoxacarb, lufenuron, metalaxyl and methomyl for Chinese cabbage. They were frequently detected pesticides in Chinese cabbage by NAQS (National Agricultural product Quality management Service) monitoring survey. In this experiment, we sprayed those pesticides 10days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day samples to establish logical equation and to calculate $DT_{50}0$. During the cultivating period, the residue amount of chlorothalonil was changed from $55.58\;mg\;kg^{-1}$ (0 day) to $20.08\;mg\;kg^{-1}$ (10 day), $DT_{50}$ was 7.45 days, indoxacarb was $7.85\;mg\;kg^{-1}$ (0 day) to $1.46\;mg\;kg^{-1}$ (10 day), and 4.2 days, lufenuron was $1.57\;mg\;kg^{-1}$ (0 day) to $0.49\;mg\;kg^{-1}$ (10 day), and 5.85 days, metalaxyl was $8.12\;mg\;kg^{-1}$ (0 day) to $0.10\;mg\;kg^{-1}$ (10 day), and 175 days, and methomyl was $11.51\;mg\;kg^{-1}$ (0 day) to $0.80\;mg\;kg^{-1}$ (10 day), and 2.42 days at single dose application, respectively. The $DT_{50}$ of double amount in those pesticides were 9.05 days in chlorothatonil, 7.09 days in indoxacarb, 8.82 days in lufenuron, 3.32 days in metalaxyl, and 2.72 days in methomyl, respectively.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1076-1082
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• 2009

Six pesticides were determined in hot pepper leaves after successive processing steps of washing, blanching, and drying. The tested pesticides included dichlofluanid, flusilazole, folpet, iprodione, ${\lambda}$-cyhalothrin, and lufenuron. Each pesticide was singly applied to the leaves of the pepper plants, which were being cultivated in a greenhouse. The processing factors were dependent on the type of pesticide, and were in the following ranges: 0.09-0.73 by washing, <0.00-0.48 after blanching, and <0.00-3.30 after drying. Only lufenuron showed a processing factor of more than 1, at 3.30 in dried leaves, while the processing factors of the other pesticides were less than 1. The removal ratios of the tested pesticides by washing ranged from 27 to 90%. The blanching step increased their removals by 10-25%. However, drying did not have an effect on residue reduction. Finally, after proceeding to the drying step, removal ratios ranged from 85 to 100%, with the exception of lufenuron at 47%.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.257-265
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• 2010

In this study, the residual levels of four insecticidal compounds (lambda-cyhalothrin, lufenuron, thiamethoxam, and clothianidin) were monitored in the pomegranate, in order to assess the risk to consumers posed by the presence of such residues. The insecticides were applied at the recommended dose rates onto pomegranate trees. The samples were then collected at harvesting time after several treatments (two, three, and four treatments). After sample preparation progressed through the clean-up procedure, lufenuron, thiamethoxam, and clothianidin residues were analyzed via a HPCL-UVD, and the lambda-cyhalothrin residue was analyzed via a GC-${\mu}ECD$. The versatility of this method was evidenced by its excellent linearity (>0.9998 to 1) at broad concentration ranges. The mean recoveries evaluated from the untreated sample spiked with two different fortification levels ranged from 72.45 to 113.90%, and the repeatability (as a relative standard deviation) resulted from triplicate recovery tests was in a range from 0.80 to 11.75%. The residues of all insecticides determined from treated pomegranate samples and their LOD levels (lunfenuron, 0.01; lambda-cyhalothrin, 0.005; thiamethoxam, 0.01; clothianidin, 0.02 mg/kg) were much lower than their MRLs (0.5 mg/kg).

• 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.16 no.4
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• pp.350-356
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• 2012

Performance of proficiency testing and the validation of analytical method was included a scheme of quality assurance in analytical chemistry laboratory to monitor a laboratory's performance abilities and produce consistently reliable data. This study was assessed the applicability of proficiency testing scheme proposed for analytical laboratories of pesticide product in domestic. The validation of analytical methods, stability and homogeneity for formulated pesticide products (emulsifiable concentrate) of emamectin benzoate and lufenuron was confirmed for the proficiency testing. The z-score of 33 participation laboratories for emamectin benzoate were that the numbers of outlier were 2 laboratories (6.0%), z-score outside the range from -3 to 3 designated "unaccptable" were 2 laboratories and z-score in the ranges -2 to -3 and 2 to 3 designated "questionable" were 3 laboratories (9.0%). Three laboratories (9.0%) showed the z-score designated "questionable" for lufenuron. The additional proficiency testing for various product types will be needed to establish the scheme of quality control.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.257-262
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• 2004

Toxicities of 51 pesticides (25 insecticides, 11, acaricides, 11 fungicides and 4 adjuvants) commonly used to control greenhouse insect, mite, and disease pests were evaluated to minute pirate bug, Orius strigicollis nymphs and adults at the recommended concentration. Among 25 insecticides tested, fipronil, lufenuron, acetamiprid+fipronil, $\alpha$-cypermethrin+flufenoxuron and buprofezin + amitraz showed low toxicity to O. strigicollis. Among acaricides, acequinocyl, bifenazate, chlorfenapyr, etoxazole, fenpyroximate, flufenoxuron, milbemectin, spirodiclofen and tebufenpyrad showed low toxicity to O. strigicollis. All fungicides and adjuvants tested were very low toxicity. It may be suggested from these results that five insecticides, nine acaricides, eleven fungicides and four adjuvants could be incorporated into the integrated thrips management system with O. strigicollis in greenhouses.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.275-281
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• 2022

We investigated the occurrence pattern of the Asian Corn Borer, Ostrinia furnacalis in job's tears, and we tested the field control effects of 5 insecticides and 3 eco-friendly materials. Adults of O. furnacalis began to occur in May and have passed three generations until the end of October. As results of the field test, five insecticides (novaluron, lufenuron, spinetoram, cyclaniliprole, flufenoxuron) and three eco-friendly materials (gosam extracts 90%, neem extracts 60%, citronella oil 30 + derris extracts 20 + cinnamon extracts 10%) showed high control effects against O. furnacalis in two different areas, and no phytotoxicity even at double dose of pesticides.