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C L Xiao - One of the best experts on this subject based on the ideXlab platform.
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occurrence and phenotypes of Pyrimethanil resistance in penicillium expansum from apple in washington state
Plant Disease, 2014Co-Authors: R Caiazzo, C L XiaoAbstract:Abstract Penicillium expansum is the cause of blue mold in stored apple fruit. In 2010–11, 779 isolates of P. expansum were collected from decayed apple fruit from five packinghouses, tested for resistance to the postharvest fungicide Pyrimethanil, and phenotyped based on the level of resistance. In 2010, 85 and 7% of the isolates were resistant to Pyrimethanil in packinghouse A and B, respectively, where Pyrimethanil had been used for four to five consecutive years. In 2011, Pyrimethanil or fludioxonil was used in packinghouse A, and 96% of the isolates from the fruit treated with Pyrimethanil were resistant but only 4% of the isolates from the fruit treated with fludioxonil were resistant to Pyrimethanil, suggesting that fungicide rotation substantially reduced the frequency of Pyrimethanil resistance. No Pyrimethanil-resistant isolates were detected in 2010 in the three other packinghouses where the fungicide had been used recently on a small scale. However 1.8% of the isolates from one of the three pa...
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first report of occurrence of Pyrimethanil resistance in penicillium expansum from stored apples in washington state
Plant Disease, 2011Co-Authors: C L Xiao, R J BoalAbstract:Blue mold caused by Penicillium expansum is a major postharvest fruit rot disease of apples (Malus domestica) worldwide. Pyrimethanil was registered in late 2004 in the United States for postharvest use on apples. Since then, Pyrimethanil has been increasingly used in Washington State as a postharvest drench treatment for control of blue mold and other postharvest diseases in apples. Baseline sensitivity to Pyrimethanil in P. expansum populations from apples in Washington State has been established and all isolates in the baseline population were sensitive to Pyrimethanil (1). To monitor resistance to Pyrimethanil in P. expansum populations, blue mold-like decayed apple fruit were sampled from May to August 2009 from the fruit that had been drenched with Pyrimethanil prior to storage from fruit packinghouses. Isolation of Penicillium species from decayed fruit was attempted. Isolates of Penicillium species were identified to species according to the descriptions by Pitt (2). In total, 186 P. expansum isol...
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resistance to thiabendazole and baseline sensitivity to fludioxonil and Pyrimethanil in botrytis cinerea populations from apple and pear in washington state
Postharvest Biology and Technology, 2010Co-Authors: Lili Huang, H Zhao, C L XiaoAbstract:Abstract Gray mold caused by Botrytis cinerea is a common postharvest disease of pome fruit. Thiabendazole was the most commonly used postharvest fungicide prior to the registration of fludioxonil and Pyrimethanil in 2004 for postharvest use on pome fruit. In this study, 83 and 40 isolates of B. cinerea that had not been exposed to fludioxonil and Pyrimethanil were obtained from apple and pear, respectively, screened for resistance to thiabendazole, and tested for sensitivity to fludioxonil and Pyrimethanil. Three isolates from apple were highly resistant to thiabendazole, while all remaining isolates were sensitive to thiabendazole. EC 50 values of fludioxonil ranged from 0.003 to 0.038 (mean = 0.005) mg/L for apple isolates and from 0.003 to 0.008 (mean = 0.005) mg/L for pear isolates. EC 50 values of Pyrimethanil ranged from 0.013 to 0.173 (mean = 0.060) mg/L and from 0.015 to 0.117 (mean = 0.048) mg/L for apple and pear isolates, respectively. One apple isolate exhibited reduced sensitivity to fludioxonil with EC 50 of 0.038 mg/L, which was significantly higher than those of remaining isolates tested and was considered resistant to fludioxonil. After 20 successive generations on potato dextrose agar and four generations on apple fruit, the fludioxonil-resistant isolate retained the same level of resistance to fludioxonil as the initial generation. However, it showed a higher sensitivity to osmotic stress in vitro , was less pathogenic and virulent on apple fruit, and produced fewer conidia in vivo at 0 °C than fludioxonil-sensitive isolates. On apple fruit at 0 °C, the fludioxonil-resistant isolate was effectively controlled by thiabendazole and Pyrimethanil but only partially controlled by fludioxonil. The results indicate that insensitivity to fludioxonil was present in a non-fludioxonil-exposed population of B. cinerea from pome fruit in the region but at a low frequency and that the vast majority of isolates in the baseline population of B. cinerea from pome fruit in the region were sensitive to and can be effectively controlled by the two newly registered postharvest fungicides.
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residual activity of fludioxonil and Pyrimethanil against penicillium expansum on apple fruit
Plant Disease, 2009Co-Authors: C L Xiao, R J BoalAbstract:Xiao, C. L., and Boal, R. J. 2009. Residual activity of fludioxonil and Pyrimethanil against Penicillium expansum on apple fruit. Plant Dis. 93:1003-1008. Blue mold caused by Penicillium expansum is a major postharvest disease of apples (Malus × domestica). Residual activity of fludioxonil and Pyrimethanil in apple fruit against P. expansum was investigated during 2005 to 2008. Fruit of the cultivar Delicious harvested from commercial orchards where fungicides were not used were either not treated or drenched with fludioxonil, Pyrimethanil, or thiabendazole prior to storage and then stored in controlled atmosphere at 0°C for 5 or 7 months, after which time the fruit were removed from storage and subjected to washing and brushing, practices that are done at the time of packing. Fruit were then wounded and inoculated with conidial suspensions of P. expansum. Inoculated fruit were treated with either sterile water or fungicides. Fruit were stored at 0°C for 8 weeks and at room temperature for one additional week after cold storage. To determine distribution of fungicide residues in the fruit flesh, fruit were cut horizontally at the equator, sprayed with the conidial suspension of P. expansum, incubated at room temperature, and examined for inhibition of blue mold on the cut fruit 4 days after inoculation. Fungicide residues on/in the fruit were analyzed using a gas chromatograph. Zero to 26% blue mold incidence was observed on fludioxonil-drenched fruit that were inoculated and not treated with fungicides at packing. No decay or 32 mm inhibition zone and approximately 5 mm inhibition zone measured from the fruit peel toward the fruit core were observed on Pyrimethanil-drenched and fludioxonil-drenched fruit, respectively. Washing and brushing at the time of packing 5 and 7 months after harvest did not remove or only partially removed residues of fludioxonil and Pyrimethanil from apple fruit. The results suggest that residues of fludioxonil and Pyrimethanil on/in apple fruit are persistent and that residual protection of apple fruit by the two fungicides can last for at least 7 months under apple-storage conditions.
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characterization of fludioxonil resistant and Pyrimethanil resistant phenotypes of penicillium expansum from apple
Phytopathology, 2008Co-Authors: H X Li, C L XiaoAbstract:ABSTRACT Penicillium expansum is the primary cause of blue mold, a major postharvest disease of apple. Fludioxonil and Pyrimethanil are two newly registered postharvest fungicides for pome fruit in the United States. To evaluate the potential risk of resistance development in P. expansum to the new postharvest fungicides, one isolate of each of thiabendazole-resistant (TBZ-R) and -sensitive (TBZ-S) P. expansum was exposed to UV radiation to generate fungicide-resistant mutants. Four fludioxonil highly-resistant mutants (EC50 > 1,000 μg/ml) and four Pyrimethanil-resistant mutants (EC50 > 10 μg/ml) were tested for sensitivities to thiabendazole, fludioxonil, and Pyrimethanil, and fitness parameters including mycelial growth, sporulation on potato dextrose agar (PDA), sensitivity to osmotic stress, and pathogenicity and sporulation on apple fruit. The stability of resistance of the mutants was tested on PDA and apple fruit. Efficacy of the three fungicides to control blue mold incited by the mutants was eval...
José Luis Vílchez - One of the best experts on this subject based on the ideXlab platform.
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Determination of Pyrimethanil and kresoxim-methyl in soils by headspace solid-phase microextraction and gas chromatography-mass spectrometry
Analytical and Bioanalytical Chemistry, 2004Co-Authors: Alberto Navalón, Avismelsi Prieto, Lilia Araujo, José Luis VílchezAbstract:A method using headspace solid-phase microextraction (HS-SPME) then gas chromatography–mass spectrometry with selected ion monitoring (GC–MS, SIM) has been developed for determination of trace amounts of the fungicides Pyrimethanil and kresoxim-methyl in soil and humic materials. Both fungicides were extracted on to a fused-silica fibre coated with 85 μm polyacrylate (PA). Response-surface methodology was used to optimise the experimental conditions. For soil samples the linear dynamic range of application was 0.004–1.000 μg g^−1 for Pyrimethanil and 0.013–1.000 μg g^−1 for kresoxim-methyl. The detection limits were 0.001 μg g^−1 and 0.004 μg g^−1 for Pyrimethanil and kresoxim-methyl, respectively. HP-SPME–GC–MS analysis was highly reproducible—relative standard deviations (RSD) were between 6.7 and 12.2%. The method was validated by analysis of spiked matrix samples and used to investigate the presence of Pyrimethanil and kresoxim-methyl above the detection limits in soil and humic materials.
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determination of Pyrimethanil and kresoxim methyl in green groceries by headspace solid phase microextraction and gas chromatography mass spectrometry
Journal of Chromatography A, 2002Co-Authors: Alberto Navalón, Avismelsi Prieto, Lilia Araujo, José Luis VílchezAbstract:A method using headspace solid-phase microextraction (HS-SPME) then gas chromatography–mass spectrometry with selected ion monitoring (GC–MS, SIM) has been developed for determination of trace amounts of the fungicides Pyrimethanil and kresoxim-methyl in soil and humic materials. Both fungicides were extracted on to a fused-silica fibre coated with 85 μm polyacrylate (PA). Response-surface methodology was used to optimise the experimental conditions. For soil samples the linear dynamic range of application was 0.004–1.000 μg g−1 for Pyrimethanil and 0.013–1.000 μg g−1 for kresoxim-methyl. The detection limits were 0.001 μg g−1 and 0.004 μg g−1 for Pyrimethanil and kresoxim-methyl, respectively. HP-SPME–GC–MS analysis was highly reproducible—relative standard deviations (RSD) were between 6.7 and 12.2%. The method was validated by analysis of spiked matrix samples and used to investigate the presence of Pyrimethanil and kresoxim-methyl above the detection limits in soil and humic materials.
Elvira Brunelli - One of the best experts on this subject based on the ideXlab platform.
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chronic exposures to fungicide Pyrimethanil multi organ effects on italian tree frog hyla intermedia
Scientific Reports, 2017Co-Authors: Ilaria Bernabo, Antonello Guardia, Rachele Macirella, Sandro Tripepi, Elvira BrunelliAbstract:Amphibian habitats are easily contaminated by several pollutants, and in agricultural landscapes the likely exposure scenario is represented by pesticides. Many of these substances are known or suspected to act as endocrine disrupting chemicals (EDCs). The goal of the present study was to assess the effects of Pyrimethanil, a common-used but also overlooked fungicide, on liver, kidney and gonadal differentiation of Hyla intermedia. Through a multi-organ evaluation, we demonstrated that a long term exposure to two environmentally relevant concentrations of Pyrimethanil (5 and 50 µg/L) elicits a range of toxic responses. First we showed that Pyrimethanil induces underdevelopment of ovaries and interferes with normal sexual differentiation, thus revealing the endocrine disruption potential of this fungicide. Moreover we revealed that all considered organs are seriously affected by this fungicide and both necrosis and apoptosis contribute to the histological response. This is the first report on the effects of Pyrimethanil on gonads, liver and kidney histology of a non-model species and it demonstrates that the hazardous properties of this fungicide can result from several pathological processes affecting different key compartments of amphibian.
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effects of long term exposure to two fungicides Pyrimethanil and tebuconazole on survival and life history traits of italian tree frog hyla intermedia
Aquatic Toxicology, 2016Co-Authors: Ilaria Bernabo, Antonello Guardia, Rachele Macirella, Settimio Sesti, Antonio Crescente, Elvira BrunelliAbstract:Over the last few years, the hazards associated with the extensive use of fungicides have become an issue of great concern but, at present, the effects of these substances on amphibians remain poorly understood. The goal of the present study was to assess the effects of two commonly used fungicides, tebuconazole and Pyrimethanil, on Italian Tree Frog (Hyla intermedia), a species frequently found in agricultural areas. Tadpoles were exposed to fungicides from developmental Gosner stage 25 (GS 25) to completion of metamorphosis (GS 46) and the whole exposure period lasted 78 days. For both tested fungicides we used two concentrations (5 and 50μg/L) that are comparable to those detected in surface waters, near agricultural fields. A variety of sublethal effects-on growth, development, behavior, and physiology-may be used for evaluating alterations induced by pollutants in amphibians. We estimated whether Pyrimethanil and tebuconazole exposure impacted on H. intermedia life history traits. For this purpose, survival, growth, development, initiation of metamorphosis, success and size at metamorphosis, time to metamorphosis, and frequency of morphological abnormalities were evaluated. We showed, for all considered endpoints, that the exposure to tebuconazole exerts more harmful effects on H. intermedia than does exposure to Pyrimethanil. Before the onset of metamorphic climax we showed, for both fungicides, that the low concentrations (5μg/L) induced significantly greater effects than the higher ones (50μg/L) on survival and deformity incidence. During the metamorphic climax, a complete reversal of this nonlinear trend takes place, and the percentage of animals initiating metamorphosis was reduced in fungicide-exposed groups in a concentration-dependent manner. Furthermore, a strong correlation emerged between fungicide exposure and the incidence of morphological abnormalities such as tail malformations, scoliosis, edema, mouth and limb deformities. Exposure to tested fungicides also caused a reduction in developmental rates just prior to the onset of metamorphic climax, which translated to a significant delay in timing of metamorphosis. We detected a drastic decrease in the success at metamorphosis in all exposed groups, compared to control group (86.25%). In fact, the percentage of survived larvae to GS 46, in the high and low concentrations, respectively, was only 22.5% and 36.25% in tebuconazole-exposed groups and 43.75% (50μg/L) and 56.25% (5μg/L) in Pyrimethanil-exposed groups. Our findings underscore the hazardous properties of these two fungicides for non-target species in the context of ecotoxicological risk assessment. No published studies have addressed the long-term effects of tebuconazole and Pyrimethanil on amphibians. To date, this is one of only a few studies documenting the effects of fungicide exposure over the whole larval development.
Alberto Navalón - One of the best experts on this subject based on the ideXlab platform.
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Determination of Pyrimethanil and kresoxim-methyl in soils by headspace solid-phase microextraction and gas chromatography-mass spectrometry
Analytical and Bioanalytical Chemistry, 2004Co-Authors: Alberto Navalón, Avismelsi Prieto, Lilia Araujo, José Luis VílchezAbstract:A method using headspace solid-phase microextraction (HS-SPME) then gas chromatography–mass spectrometry with selected ion monitoring (GC–MS, SIM) has been developed for determination of trace amounts of the fungicides Pyrimethanil and kresoxim-methyl in soil and humic materials. Both fungicides were extracted on to a fused-silica fibre coated with 85 μm polyacrylate (PA). Response-surface methodology was used to optimise the experimental conditions. For soil samples the linear dynamic range of application was 0.004–1.000 μg g^−1 for Pyrimethanil and 0.013–1.000 μg g^−1 for kresoxim-methyl. The detection limits were 0.001 μg g^−1 and 0.004 μg g^−1 for Pyrimethanil and kresoxim-methyl, respectively. HP-SPME–GC–MS analysis was highly reproducible—relative standard deviations (RSD) were between 6.7 and 12.2%. The method was validated by analysis of spiked matrix samples and used to investigate the presence of Pyrimethanil and kresoxim-methyl above the detection limits in soil and humic materials.
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determination of Pyrimethanil and kresoxim methyl in green groceries by headspace solid phase microextraction and gas chromatography mass spectrometry
Journal of Chromatography A, 2002Co-Authors: Alberto Navalón, Avismelsi Prieto, Lilia Araujo, José Luis VílchezAbstract:A method using headspace solid-phase microextraction (HS-SPME) then gas chromatography–mass spectrometry with selected ion monitoring (GC–MS, SIM) has been developed for determination of trace amounts of the fungicides Pyrimethanil and kresoxim-methyl in soil and humic materials. Both fungicides were extracted on to a fused-silica fibre coated with 85 μm polyacrylate (PA). Response-surface methodology was used to optimise the experimental conditions. For soil samples the linear dynamic range of application was 0.004–1.000 μg g−1 for Pyrimethanil and 0.013–1.000 μg g−1 for kresoxim-methyl. The detection limits were 0.001 μg g−1 and 0.004 μg g−1 for Pyrimethanil and kresoxim-methyl, respectively. HP-SPME–GC–MS analysis was highly reproducible—relative standard deviations (RSD) were between 6.7 and 12.2%. The method was validated by analysis of spiked matrix samples and used to investigate the presence of Pyrimethanil and kresoxim-methyl above the detection limits in soil and humic materials.
Ilaria Bernabo - One of the best experts on this subject based on the ideXlab platform.
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chronic exposures to fungicide Pyrimethanil multi organ effects on italian tree frog hyla intermedia
Scientific Reports, 2017Co-Authors: Ilaria Bernabo, Antonello Guardia, Rachele Macirella, Sandro Tripepi, Elvira BrunelliAbstract:Amphibian habitats are easily contaminated by several pollutants, and in agricultural landscapes the likely exposure scenario is represented by pesticides. Many of these substances are known or suspected to act as endocrine disrupting chemicals (EDCs). The goal of the present study was to assess the effects of Pyrimethanil, a common-used but also overlooked fungicide, on liver, kidney and gonadal differentiation of Hyla intermedia. Through a multi-organ evaluation, we demonstrated that a long term exposure to two environmentally relevant concentrations of Pyrimethanil (5 and 50 µg/L) elicits a range of toxic responses. First we showed that Pyrimethanil induces underdevelopment of ovaries and interferes with normal sexual differentiation, thus revealing the endocrine disruption potential of this fungicide. Moreover we revealed that all considered organs are seriously affected by this fungicide and both necrosis and apoptosis contribute to the histological response. This is the first report on the effects of Pyrimethanil on gonads, liver and kidney histology of a non-model species and it demonstrates that the hazardous properties of this fungicide can result from several pathological processes affecting different key compartments of amphibian.
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effects of long term exposure to two fungicides Pyrimethanil and tebuconazole on survival and life history traits of italian tree frog hyla intermedia
Aquatic Toxicology, 2016Co-Authors: Ilaria Bernabo, Antonello Guardia, Rachele Macirella, Settimio Sesti, Antonio Crescente, Elvira BrunelliAbstract:Over the last few years, the hazards associated with the extensive use of fungicides have become an issue of great concern but, at present, the effects of these substances on amphibians remain poorly understood. The goal of the present study was to assess the effects of two commonly used fungicides, tebuconazole and Pyrimethanil, on Italian Tree Frog (Hyla intermedia), a species frequently found in agricultural areas. Tadpoles were exposed to fungicides from developmental Gosner stage 25 (GS 25) to completion of metamorphosis (GS 46) and the whole exposure period lasted 78 days. For both tested fungicides we used two concentrations (5 and 50μg/L) that are comparable to those detected in surface waters, near agricultural fields. A variety of sublethal effects-on growth, development, behavior, and physiology-may be used for evaluating alterations induced by pollutants in amphibians. We estimated whether Pyrimethanil and tebuconazole exposure impacted on H. intermedia life history traits. For this purpose, survival, growth, development, initiation of metamorphosis, success and size at metamorphosis, time to metamorphosis, and frequency of morphological abnormalities were evaluated. We showed, for all considered endpoints, that the exposure to tebuconazole exerts more harmful effects on H. intermedia than does exposure to Pyrimethanil. Before the onset of metamorphic climax we showed, for both fungicides, that the low concentrations (5μg/L) induced significantly greater effects than the higher ones (50μg/L) on survival and deformity incidence. During the metamorphic climax, a complete reversal of this nonlinear trend takes place, and the percentage of animals initiating metamorphosis was reduced in fungicide-exposed groups in a concentration-dependent manner. Furthermore, a strong correlation emerged between fungicide exposure and the incidence of morphological abnormalities such as tail malformations, scoliosis, edema, mouth and limb deformities. Exposure to tested fungicides also caused a reduction in developmental rates just prior to the onset of metamorphic climax, which translated to a significant delay in timing of metamorphosis. We detected a drastic decrease in the success at metamorphosis in all exposed groups, compared to control group (86.25%). In fact, the percentage of survived larvae to GS 46, in the high and low concentrations, respectively, was only 22.5% and 36.25% in tebuconazole-exposed groups and 43.75% (50μg/L) and 56.25% (5μg/L) in Pyrimethanil-exposed groups. Our findings underscore the hazardous properties of these two fungicides for non-target species in the context of ecotoxicological risk assessment. No published studies have addressed the long-term effects of tebuconazole and Pyrimethanil on amphibians. To date, this is one of only a few studies documenting the effects of fungicide exposure over the whole larval development.
