The Experts below are selected from a list of 3957 Experts worldwide ranked by ideXlab platform
Themis J. Michailides - One of the best experts on this subject based on the ideXlab platform.
-
Resistance to Thiophanate-Methyl in Botrytis cinerea Isolates From Californian Vineyards and Pistachio and Pomegranate Orchards.
Plant Disease, 2020Co-Authors: Hervé F. Avenot, David P. Morgan, Joel Quattrini, Themis J. MichailidesAbstract:In this study, a mycelial growth assay was used to evaluate the sensitivity to Thiophanate-Methyl of 144 Botrytis cinerea isolates (collection A) from Californian vineyards and pistachio and pomegranate orchards. Based on the effective concentration that inhibits 50% of growth (EC50) values for mycelial growth inhibition on fungicide-amended media, 3, 28, 10, and 58% of the isolates showed sensitivity (SS; EC50 100 µg/ml) toward Thiophanate-Methyl, respectively. The LR and HR phenotypes were observed in pistachio and pomegranate orchards, even though pomegranate was not sprayed with Thiophanate-Methyl. Sensitivity to Thiophanate-Methyl of a historical collection of 257 B. cinerea isolates (collection B) isolated from pistachio orchards in 1992, 2005, and 2006 was assessed on potato dextrose agar amended with Thiophanate-Methyl at the discriminatory concentration of 10 µg/ml. Average percentages of Thiophanate-Methyl-resistant isolates were 50, 72, and 64% in the orchards in 1992, 2005, and 2006, respectively. A study of fitness components of selected Thiophanate-Methyl-resistant (LR, WR, and HR) and -sensitive (SS) isolates from collection A did not reveal any significant difference between them with respect to mycelial growth on fungicide-free media and pathogenicity on cultivar Crimson Seedless berries. Comparison of β-tubulin sequences from resistant and sensitive phenotypes revealed that a glutamic acid at position 198 was changed to alanine in all HR isolates and three LR isolates. The occurrence of Thiophanate-Methyl resistance in B. cinerea populations should be considered when designing spray programs against blossom and shoot blight of pistachio and gray mold of grape.
-
sensitivity of monilinia fructicola from stone fruit to Thiophanate Methyl iprodione and tebuconazole
Plant Disease, 2004Co-Authors: Michael A Yoshimura, Yong Luo, Themis J. MichailidesAbstract:ABSTRACT Sensitivity in Monilinia fructicola to three fungicides was determined by measuring mycelial growth in fungicide-amended media. Resistance to Thiophanate-Methyl was found in 39 of 52 isolates (75%) collected from 1992 to 1998 (historic population) and 22 of 100 isolates (22%) collected in 2002 (current population). Three groups having distinct ranges of values for 50% effective concentration (EC50) to Thiophanate-Methyl were identified. Benzimidazole-sensitive (benS) isolates had EC50 values less than 2.0, low-resistant (benL) isolates between 2.0 and 30.0, and high-resistant (benH) isolates greater than 30.0 μg/ml. One (2%) isolate from the historic and three (3%) isolates from the current population were benH. Inoculation of untreated nectarine blossoms with four isolates from each of the three groups, individually or combined using equal numbers of conidia from each isolate, showed that the benS, benL, and benH isolates were equally pathogenic and competitive. Use of Thiophanate-Methyl at 300 ...
-
sensitivity of monilinia fructicola from stone fruit to Thiophanate Methyl iprodione and tebuconazole
Plant Disease, 2004Co-Authors: Michael A Yoshimura, Yong Luo, Themis J. MichailidesAbstract:Sensitivity in Monilinia fructicola to three fungicides was determined by measuring mycelial growth in fungicide-amended media. Resistance to Thiophanate-Methyl was found in 39 of 52 isolates (75%) collected from 1992 to 1998 (historic population) and 22 of 100 isolates (22%) collected in 2002 (current population). Three groups having distinct ranges of values for 50% effective concentration (EC50) to Thiophanate-Methyl were identified. Benzimidazole-sensitive (benS) isolates had EC50 values less than 2.0, low-resistant (benL) isolates between 2.0 and 30.0, and high-resistant (benH) isolates greater than 30.0 μg/ml. One (2%) isolate from the historic and three (3%) isolates from the current population were benH. Inoculation of untreated nectarine blossoms with four isolates from each of the three groups, individually or combined using equal numbers of conidia from each isolate, showed that the benS, benL, and benH isolates were equally pathogenic and competitive. Use of Thiophanate-Methyl at 300 μg a.i./ml (half dosage) and 600 μg a.i./ml (full dosage) effectively reduced the percentage of blighted blossoms caused by the benS group but not that caused by the benL and benH groups. The benH isolates caused significantly greater percentage of blighted blossoms than the benL isolates at both dosage levels. None of the tested isolates of M. fructicola were resistant to either iprodione or tebuconazole.
Jiye Hu - One of the best experts on this subject based on the ideXlab platform.
-
residue dissipation and risk assessment of tebuconazole Thiophanate Methyl and its metabolite in table grape by liquid chromatography tandem mass spectrometry
Food Chemistry, 2018Co-Authors: Bizhang Dong, Nannan Pang, Yuanping Yang, Jiye HuAbstract:Abstract An efficient method was developed and validated for simultaneous determination of tebuconazole, Thiophanate-Methyl and its metabolite carbendazim in grape and soil using QuEChERS procedure and liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 83.2%–105.4%, the limit of detection (LOD) ranged from 2.1 × 10 −5 to 8.7 × 10 −4 mg L −1 , and the limit of quantitation (LOQ) was 0.1 mg kg −1 . The field results showed that tebuconazole and Thiophanate-Methyl in soil and grape were rapidly dissipated with half-lives less than 24.7 days. The terminal residues of all analytes in grape were lower than the maximum residue limit (MRL) set by China (2 mg kg −1 for tebuconazole; 3 mg kg −1 for both Thiophanate-Methyl and carbendazim). Risk assessment showed that tebuconazole, Thiophanate-Methyl and its metabolite would be unlikely to cause health problems. However, carbendazim, the higher active metabolites of Thiophanate-Methyl, should receive more concerns.
Yongquan Zheng - One of the best experts on this subject based on the ideXlab platform.
-
effect of household canning on the distribution and reduction of Thiophanate Methyl and its metabolite carbendazim residues in tomato
Food Control, 2014Co-Authors: Fengshou Dong, Zenglong Chen, Youpu Cheng, Yuanbo Li, Jun Xu, Yongquan ZhengAbstract:Tomato in the field was sprayed with Thiophanate-Methyl to quantify the effect of household processing on pesticide residues. Changes in the residue levels of Thiophanate-Methyl and its metabolite carbendazim in tomatoes were assessed during home-canning processing. Pesticide residues in tomato were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after washing, peeling, homogenization, simmering, and sterilization. Results showed that washing with tap water reduced Thiophanate-Methyl residues by 25.0% and carbendazim residues by 13.0%. The peeling process yielded 84.2% loss in Thiophanate-Methyl and 87.3% loss in carbendazim from tomatoes. Peeling is thus the most effective step to remove pesticide residues from tomatoes. Homogenization, simmering, and sterilization exerted limited effects on the removal of Thiophanate-Methyl and carbendazim. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PFs of the peeling process for Thiophanate-Methyl and carbendazim were 0.19 and 0.14, respectively.
Michael A Yoshimura - One of the best experts on this subject based on the ideXlab platform.
-
sensitivity of monilinia fructicola from stone fruit to Thiophanate Methyl iprodione and tebuconazole
Plant Disease, 2004Co-Authors: Michael A Yoshimura, Yong Luo, Themis J. MichailidesAbstract:ABSTRACT Sensitivity in Monilinia fructicola to three fungicides was determined by measuring mycelial growth in fungicide-amended media. Resistance to Thiophanate-Methyl was found in 39 of 52 isolates (75%) collected from 1992 to 1998 (historic population) and 22 of 100 isolates (22%) collected in 2002 (current population). Three groups having distinct ranges of values for 50% effective concentration (EC50) to Thiophanate-Methyl were identified. Benzimidazole-sensitive (benS) isolates had EC50 values less than 2.0, low-resistant (benL) isolates between 2.0 and 30.0, and high-resistant (benH) isolates greater than 30.0 μg/ml. One (2%) isolate from the historic and three (3%) isolates from the current population were benH. Inoculation of untreated nectarine blossoms with four isolates from each of the three groups, individually or combined using equal numbers of conidia from each isolate, showed that the benS, benL, and benH isolates were equally pathogenic and competitive. Use of Thiophanate-Methyl at 300 ...
-
sensitivity of monilinia fructicola from stone fruit to Thiophanate Methyl iprodione and tebuconazole
Plant Disease, 2004Co-Authors: Michael A Yoshimura, Yong Luo, Themis J. MichailidesAbstract:Sensitivity in Monilinia fructicola to three fungicides was determined by measuring mycelial growth in fungicide-amended media. Resistance to Thiophanate-Methyl was found in 39 of 52 isolates (75%) collected from 1992 to 1998 (historic population) and 22 of 100 isolates (22%) collected in 2002 (current population). Three groups having distinct ranges of values for 50% effective concentration (EC50) to Thiophanate-Methyl were identified. Benzimidazole-sensitive (benS) isolates had EC50 values less than 2.0, low-resistant (benL) isolates between 2.0 and 30.0, and high-resistant (benH) isolates greater than 30.0 μg/ml. One (2%) isolate from the historic and three (3%) isolates from the current population were benH. Inoculation of untreated nectarine blossoms with four isolates from each of the three groups, individually or combined using equal numbers of conidia from each isolate, showed that the benS, benL, and benH isolates were equally pathogenic and competitive. Use of Thiophanate-Methyl at 300 μg a.i./ml (half dosage) and 600 μg a.i./ml (full dosage) effectively reduced the percentage of blighted blossoms caused by the benS group but not that caused by the benL and benH groups. The benH isolates caused significantly greater percentage of blighted blossoms than the benL isolates at both dosage levels. None of the tested isolates of M. fructicola were resistant to either iprodione or tebuconazole.
Kankan Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Determination of Thiophanate-Methyl and Carbendazim in Rapeseed by Solid–Phase Extraction and Ultra–High Performance Chromatography with Photodiode Array Detection
Instrumentation Science & Technology, 2015Co-Authors: Hongyu Chen, Wen Zhang, Zaihui Yang, Mingming Tang, Jing Zhang, Huijun Zhu, Kankan ZhangAbstract:A rapid and reliable ultra-high performance liquid chromatography method using a photodiode array detector with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed to determine Thiophanate-Methyl and carbendazim in rapeseed. Samples were extracted with acetonitrile and partitioned with a mixture of NaCl and anhydrous MgSO4. The cleanup step was performed using dispersive solid-phase extraction with anhydrous MgSO4 and primary secondary amine. This step was repeated to improve the results. The limits of detection and quantification of Thiophanate-Methyl and carbendazim in rapeseed were 15 and 50 μg kg−1, respectively. The recoveries of Thiophanate-Methyl and carbendazim were from 77.44–100.9%, with relative standard deviations between 2.20% and 6.62%. The method was employed to determine Thiophanate-Methyl and carbendazim in rapeseed. This study has established a novel method and a safety evaluation system for the analytes in rapeseed.
-
determination of Thiophanate Methyl and carbendazim in rapeseed by solid phase extraction and ultra high performance chromatography with photodiode array detection
Instrumentation Science & Technology, 2015Co-Authors: Hongyu Chen, Wen Zhang, Zaihui Yang, Mingming Tang, Jing Zhang, Huijun Zhu, Kankan ZhangAbstract:A rapid and reliable ultra-high performance liquid chromatography method using a photodiode array detector with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed to determine Thiophanate-Methyl and carbendazim in rapeseed. Samples were extracted with acetonitrile and partitioned with a mixture of NaCl and anhydrous MgSO4. The cleanup step was performed using dispersive solid-phase extraction with anhydrous MgSO4 and primary secondary amine. This step was repeated to improve the results. The limits of detection and quantification of Thiophanate-Methyl and carbendazim in rapeseed were 15 and 50 μg kg−1, respectively. The recoveries of Thiophanate-Methyl and carbendazim were from 77.44–100.9%, with relative standard deviations between 2.20% and 6.62%. The method was employed to determine Thiophanate-Methyl and carbendazim in rapeseed. This study has established a novel method and a safety evaluation system for the analytes in rapeseed.