azoxystrobin and pyrachlostrobin

Topics: Fungicides, Industrial; Glycine max; Kentucky; Thiophanate; United States

Continuous fungicide spraying is required to eliminate fungal pathogens on grapes. However, this practice is associated with several risks, including contamination and environmental imbalance, as well as toxicity to operators and the induction of resistance in pathogens. In addition, a strong correlation has been reported between the presence of fungicides and the occurrence of issues during alcoholic fermentation, resulting in negative impacts on the sensory quality of the final products. Numerous studies have evaluated residue concentrations of phytosanitary products in grapes, juices, and wines, and a significant number of studies have assessed the impact of different agrochemicals on bioprocesses. However, a review compiling the key results of these studies is currently lacking. This review incorporates results obtained in the last decade from research on the presence of fungicide residues, including azoxystrobin, boscalid, captan, copper, fenhexamid, folpet, pyraclostrobin, pyrimethanil and tebuconazole, and their effects on fermentation kinetics. Practical solutions to mitigate these problems, both in vineyards and industry, are also presented and discussed. This review highlights the constant high fungicidal agent concentrations (greater than 1 or 2 mg L

Topics: Fermentation; Food Contamination; Fungicides, Industrial; Humans; Pyrimidines; Saccharomyces cerevisiae; Strobilurins; Triazoles; Wine

The use of foliar fungicides on field corn has increased greatly over the past 5 years in the United States in an attempt to increase yields, despite limited evidence that use of the fungicides is consistently profitable. To assess the value of using fungicides in grain corn production, random-effects meta-analyses were performed on results from foliar fungicide experiments conducted during 2002 to 2009 in 14 states across the United States to determine the mean yield response to the fungicides azoxystrobin, pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin. For all fungicides, the yield difference between treated and nontreated plots was highly variable among studies. All four fungicides resulted in a significant mean yield increase relative to the nontreated plots (P < 0.05). Mean yield difference was highest for propiconazole + trifloxystrobin (390 kg/ha), followed by propiconazole + azoxystrobin (331 kg/ha) and pyraclostrobin (256 kg/ha), and lowest for azoxystrobin (230 kg/ha). Baseline yield (mean yield in the nontreated plots) had a significant effect on yield for propiconazole + azoxystrobin (P < 0.05), whereas baseline foliar disease severity (mean severity in the nontreated plots) significantly affected the yield response to pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin but not to azoxystrobin. Mean yield difference was generally higher in the lowest yield and higher disease severity categories than in the highest yield and lower disease categories. The probability of failing to recover the fungicide application cost (p(loss)) also was estimated for a range of grain corn prices and application costs. At the 10-year average corn grain price of $0.12/kg ($2.97/bushel) and application costs of $40 to 95/ha, p(loss) for disease severity <5% was 0.55 to 0.98 for pyraclostrobin, 0.62 to 0.93 for propiconazole + trifloxystrobin, 0.58 to 0.89 for propiconazole + azoxystrobin, and 0.91 to 0.99 for azoxystrobin. When disease severity was >5%, the corresponding probabilities were 0.36 to 95, 0.25 to 0.69, 0.25 to 0.64, and 0.37 to 0.98 for the four fungicides. In conclusion, the high p(loss) values found in most scenarios suggest that the use of these foliar fungicides is unlikely to be profitable when foliar disease severity is low and yield expectation is high.

Topics: Acetates; Carbamates; Edible Grain; Fungicides, Industrial; Imines; Methacrylates; Plant Diseases; Plant Leaves; Pyrazoles; Pyrimidines; Risk Factors; Strobilurins; Triazoles; United States; Zea mays

Despite the widespread application of strobilurin fungicides (SFs) in agriculture, little is known about their distribution and bioaccumulation in aquatic ecosystems. In this study, the concentrations of 12 SFs and two of their metabolites were determined in abiotic (water and sediment; n = 83) and biotic (plant, algae, zooplankton, and fish; n = 123) samples collected from a subtropical freshwater ecosystem, namely, Dongjiang River wetland, in southern China. Among the 12 SFs measured, azoxystrobin (AZ) was the major fungicide found in surface water (median: 2.20 ng/L) and sediment (0.064 ng/g dry wt.). Azoxystrobin acid (AZ-acid), a metabolite of AZ, was the major analyte in the plant samples and had a median concentration at 0.36 ng/g dry wt. In algae and zooplankton, (Z)-metominostrobin was the predominant fungicide and had median concentrations of 3.52 and 5.55 ng/g dry wt., respectively. In fish muscle, dimoxystrobin (DIMO) was the major SF and had a median concentration of 0.47 ng/g dry wt. The bioconcentration factor (BCF) values of AZ-acid, trifloxystrobin (TFS), and pyraclostrobin (PYR) in algae and zooplankton and AZ-acid, PYR, TFS, TFS-acid, picoxystrobin, and DIMO in fish muscle exceeded 1000 L/kg (algae, zooplankton, and fish concentrations were expressed on a dry weight basis), suggesting that these fungicides can accumulate in biota. A positive association between log BCFs of SFs in fish and logKow of SFs and a negative correlation between log BCFs and the log solubility index were observed. Additionally, the risk quotient (RQ) was calculated to evaluate the potential ecotoxicological risk of SFs to different aquatic organisms (algae, zooplankton, and fish). The PYR and DIMO concentrations at 19 sampling sites had RQ values >0.1, indicating moderate ecotoxicological risks to aquatic organisms. This study is the first to document the widespread occurrence of SFs and their metabolites in aquatic ecosystems and to elucidate the bioaccumulation potential of SFs in aquatic organisms.

Topics: Animals; Aquatic Organisms; Bioaccumulation; China; Ecosystem; Environmental Monitoring; Fishes; Fungicides, Industrial; Rivers; Strobilurins; Water; Water Pollutants, Chemical; Zooplankton

Topics: Animals; Bees; Fungicides, Industrial; Hymenoptera

Topics: Animals; Bees; Fungicides, Industrial; Gastrointestinal Microbiome

Fritillaria (Beimu in Chinese) is a well-known traditional Chinese medicinal herbal and valuable health food, which has attracted more and more attention. In this study, an efficient method was developed to determine pyraclostrobin, fluxapyroxad, difenoconazole, and azoxystrobin in plants, fresh Fritillaria, dry Fritillaria, and soil via liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 78.9-109.7% with relative standard deviations of 0.94-11.1%. The dissipation half-lives of the four fungicides were 4.4-7.7 days in the Fritillaria plant and 11.6-18.2 days in the soil. The terminal residues of four fungicides were 0.033-0.13 mg/kg in fresh Fritillaria, 0.096-0.42 mg/kg in dry Fritillaria, and 0.12-0.74 mg/kg in soil. In the risk assessment of dietary exposure, all the chronic hazard quotient and acute hazard quotient index values were far below 100%, which were both acceptable to consumers. Accordingly, 7 days was recommended as the pre-harvest interval for the four fungicides in Fritillaria. This work could guide the safe use of these fungicides in Fritillaria and also give a reference for the Chinese government to establish the maximum residue limits (MRLs).

Topics: Amides; China; Dietary Exposure; Dioxolanes; Ecosystem; Fritillaria; Fungicides, Industrial; Pesticide Residues; Pyrimidines; Risk Assessment; Soil; Strobilurins; Tandem Mass Spectrometry; Triazoles

Azoxystrobin (AZ) and pyraclostrobin (PY) are strobilurin fungicides that inhibit fungal mitochondrial respiration. In this study, a representative model, zebrafish (Danio rerio), was used as a test species for acute and developmental toxicity. Survival and malformation rates were observed only PY-treated embryos, with an LC

Topics: Animals; Embryo, Nonmammalian; Pyrimidines; Strobilurins; Water Pollutants, Chemical; Zebrafish

Pomegranate crop is affected by several insect pests and requires usage of a large number of pesticides, but the information on their behavior in pomegranate tissues is limited. A study was conducted to assess the behavior of acetamiprid, azoxystrobin, pyraclostrobin, and lambda-cyhalothrin in pomegranate fruits and leaves. The QuEChERS analytical method and LC-MS/MS and GC-MS were used for quantification of the analytes. The LOD (limit of detection) of acetamiprid, azoxystrobin, and pyraclostrobin was 0.0015 mg kg

Topics: Chromatography, Liquid; Fruit; Neonicotinoids; Nitriles; Pesticide Residues; Pomegranate; Pyrethrins; Pyrimidines; Strobilurins; Tandem Mass Spectrometry

Azoxystrobin and pyraclostrobin are broad spectrum strobilurin fungicides that have been measured in the aquatic environment. Strobilurins inhibit mitochondrial respiration by binding to the mitochondrial respiratory complex III. The goal of this study was to investigate mitochondrial dysfunction and oxidative stress in the developing zebrafish from exposure to azoxystrobin and pyraclostrobin. Exposure studies were performed where zebrafish embryos were exposed to azoxystrobin and pyraclostrobin at 0.1, 10, 100 μg/L from 4 hpf to 48 hpf to measure mitochondrial dysfunction and oxidative stress mRNA transcripts, and 5 dpf to measure movement, growth, oxygen consumption, enzymatic activities, and mRNA transcripts. Results from this study indicated that there was a significant reduction in both basal and maximal respiration at 48 hpf in zebrafish exposed to 100 μg/L of pyraclostrobin. There was no difference in oxidative stress or apoptotic mRNA transcripts at 48 hpf, indicating that the two strobilurins were acting first on mitochondrial function and not directly through oxidative stress. At 5 dpf, standard body length was significantly reduced with exposure to pyraclostrobin and azoxystrobin exposure as compared to the control. These reductions in apical endpoints corresponded with increases in oxidative stress and apoptotic mRNA transcripts in treatment groups at 5 dpf indicating that strobilurins' exposure followed the adverse outcome pathway for mito-toxicants. Our results indicate that strobilurins can decrease mitochondrial function, which in turn lead to diminished growth and movement.

Topics: Animals; Embryo, Nonmammalian; Embryonic Development; Fungicides, Industrial; Larva; Mitochondria; Oxidative Stress; Pyrimidines; Strobilurins; Water Pollutants, Chemical; Zebrafish

Strobilurin fungicides are used primarily in fruits and vegetables, but recently, a patent was issued for one strobilurin fungicide, azoxystrobin, in mold-resistant wallboard. This raises concerns about the potential presence of these chemicals in house dust and potential exposure indoors, particularly in young children. Furthermore, recent toxicological studies have suggested that strobilurins may cause neurotoxicity. Currently, it is not clear whether or not azoxystrobin applications in wallboard lead to exposures in the indoor environments. The purpose of this study was to determine if azoxystrobin, and related strobilurins, could be detected in house dust. We also sought to characterize the concentrations of azoxystrobin in new wallboard samples. To support this study, we collected and analyzed 16 new dry wall samples intentionally marketed for use in bathrooms to inhibit mold. We then analyzed 188 house dust samples collected from North Carolina homes in 2014-2016 for azoxystrobin and related strobilurins, including pyraclostrobin, trifloxystrobin, and fluoxastrobin using liquid chromatography tandem mass spectrometry. Detection frequencies for azoxystrobin, pyraclostrobin, trifloxystrobin, and fluoxastrobin ranged from 34-87%, with azoxystrobin being detected most frequently and at the highest concentrations (geometric mean = 3.5 ng/g; maximum = 10,590 ng/g). Azoxystrobin was also detected in mold-resistant wallboard samples, primarily in the paper covering where it was found at concentrations up to 88.5 µg/g. Cumulatively, these results suggest that fungicides present in wallboard may be migrating to the indoor environment, leading to exposure in the residences that would constitute a separate exposure pathway independent of dietary exposures.

Topics: Acetates; Air Pollution, Indoor; Chromatography, Liquid; Construction Industry; Dust; Fungicides, Industrial; Imines; North Carolina; Pyrimidines; Strobilurins

Topics: Chromatography, Liquid; Fruit; Fungicides, Industrial; Kinetics; Limit of Detection; Linear Models; Mineral Oil; Musa; Pesticide Residues; Plant Leaves; Pyrimidines; Reproducibility of Results; Soil; Solid Phase Extraction; Strobilurins; Tandem Mass Spectrometry

Topics: Acrylates; Adenosine Triphosphate; Binding Sites; Chlorella vulgaris; Coumarins; Dose-Response Relationship, Drug; Electron Transport Complex III; Fungicides, Industrial; Molecular Docking Simulation; Oxidation-Reduction; Pyrimidines; Strobilurins; Toxicity Tests, Acute; Ubiquinone; Water Pollutants, Chemical

The long-term decline of monarch butterflies has been attributed to loss of their milkweed (Asclepias sp.) host-plants after the introduction of herbicide-tolerant crops. However, recent studies report pesticide residues on milkweed leaves that could act as a contributing factor when ingested as part of their larval diet. In this study, we exposed monarch larvae to six pesticides (insecticide: clothianidin; herbicides: atrazine, S-metolachlor; fungicides: azoxystrobin, pyraclostrobin, trifloxystrobin) on their primary host-plant, A. syriaca. Each was tested at mean and maximum levels reported from published analyses of milkweeds bordering cropland and thus represent field-relevant concentrations. Monarch lethal and sub-lethal responses were tracked over their complete development, from early instar larvae to adult death. Overall, we found no impact of any pesticide on immature development time and relatively weak effects on larval herbivory or survival to adulthood. Comparatively stronger effects were detected for adult performance; namely, a 12.5% reduction in wing length in response to the fungicides azoxystrobin and trifloxystrobin. These data collectively suggest that monarch responses to host-plant pesticides are largely sublethal and more pronounced in the adult stage, despite exposure only as larvae. This outcome has important implications for risk assessment and the migratory success of monarchs in North America.

Topics: Acetamides; Acetates; Animal Migration; Animals; Asclepias; Atrazine; Butterflies; Ecosystem; Fungicides, Industrial; Herbicides; Herbivory; Imines; Larva; Pesticides; Population Dynamics; Pyrimidines; Risk Assessment; Strobilurins

Sensitivity of 24 isolates of

Topics: Colletotrichum; Fungal Proteins; Fungicides, Industrial; Medicago sativa; Plant Diseases; Pyrimidines; Serbia; Strobilurins; Succinate Dehydrogenase; Triazoles

Extensive use of the fungicides azoxystrobin (AZ) and pyraclostrobin (PYR) can have negative effects on aquatic environments, but comprehensive studies on their effect on aquatic microbial communities are still lacking. We found that AZ and PYR could both inhibit the growth of Chlorella vulgaris, but PYR also inhibited Microcystis aeruginosa more strongly than did AZ. High-throughput sequencing analysis showed that AZ promoted the growth of Cyanobacteria in microcosms, and both PYR and AZ disturbed the ecological balance in the aquatic bacterial community and created distinct ecological risks. Our study suggests that the ecological risk of fungicides is complex, and fungicide use should be better managed to reduce potential risks to the environment.

Topics: China; Chlorella vulgaris; Cyanobacteria; Ecotoxicology; Fresh Water; Fungicides, Industrial; Microcystis; Pyrimidines; Strobilurins

Crop protection agents are widely used in modern agriculture and exert direct effects on non-target microorganisms such as yeasts. Yeasts abundantly colonize wheat grain and affect its chemical composition. They can also limit pathogen growth. This study evaluated the sensitivity of yeast communities colonizing winter wheat kernels to benzimidazole, strobilurin, triazole and morpholine fungicides, trinexapac-ethyl, a commercial mixture of o-nitrophenol+p-nitrophenol+5-nitroguaiacol, and chitosan applied during the growing season of winter wheat and in vitro in a diffusion test. A molecular identification analysis of yeasts isolated from winter wheat kernels was performed, and nucleotide polymorphisms in the CYTb gene (G143A) conferring resistance to strobilurin fungicides in yeast cells were identified. The size of yeast communities increased during grain storage, and the total counts of endophytic yeasts were significantly (85%) reduced following intensive fungicide treatment (fenpropimorph, a commercial mixture of pyraclostrobin, epoxiconazole and thiophanate-methyl). This study demonstrated that agrochemical residues in wheat grain can drive selection of yeast communities for reduced sensitivity to xenobiotics. A mutation in the CYTb gene (G143A) was observed in all analyzed isolates of the following azoxystrobin-resistant species: Aureobasidium pullulans, Debaryomyces hansenii, Candida albicans and C. sake. Agrochemicals tested in vitro were divided into four classes of toxicity to yeasts: (1) tebuconazole and a commercial mixture of flusilazole and carbendazim - most toxic to yeasts; (2) fenpropimorph and a commercial mixture of pyraclostrobin and epoxyconazole; (3) propiconazole, chitosan, thiophanate-methyl and a commercial mixture of o-nitrophenol, p-nitrophenol and 5-nitroguaiacol; (4) trinexapac-ethyl and azoxystrobin - least toxic to yeasts. It was found that agrochemicals can have an adverse effect on yeast abundance and the composition of yeast communities, mostly due to differences in fungicide resistance between yeast species, including the clinically significant C. albicans.

Topics: Agaricales; Agrochemicals; Ascomycota; Benzimidazoles; Candida albicans; Carbamates; Drug Resistance, Fungal; Epoxy Compounds; Fungicides, Industrial; Microbial Sensitivity Tests; Pesticide Residues; Plant Diseases; Pyrimidines; Seasons; Silanes; Strobilurins; Triazoles; Triticum; Xenobiotics; Yeasts

Phytophthora capsici is a highly destructive plant pathogen that has spread worldwide. To date, the quinone outside inhibitor (QoI) azoxystrobin has been the choice of farmers for managing this oomycete. In this study, the sensitivity of 90 P. capsici isolates collected from Yunnan, Fujian, Jiangxi, Zhejiang, and Guangdong in southern China to azoxystrobin was assessed based on mycelial growth, sporangia formation, and zoospore discharge. Furthermore, the mitochondrial cytochrome b (cytb) gene from azoxystrobin-sensitive and -resistant P. capsici isolates was compared to investigate the mechanism of QoI resistance. The high values for effective concentration to inhibit 50% of mycelial growth and large variation factor obtained provide strong support for the existence of azoxystrobin-resistant subpopulations in wild populations. The resistance frequency of P. capsici to azoxystrobin was greater than 40%. Sensitive P. capsici isolates were strongly suppressed on V8 medium plates containing azoxystrobin supplemented with salicylhydroxamic acid at 50 µg ml

Topics: Amino Acid Sequence; Amino Acid Substitution; Capsicum; Cytochromes b; Fungicides, Industrial; Phytophthora; Plant Diseases; Pyrimidines; Sequence Alignment; Strobilurins

Quinone outside inhibitors (QoIs), which inhibit the mitochondrial respiratory system by binding to the Qo site of Complex III in fungi, are widely used as pesticides with broad spectrum antifungal activity. However, excessive use of QoIs leads to pesticide resistance through mutation of amino acid residues in the Qo site. Recently, metyltetraprole, a novel QoI that is effective against wild-type and resistant mutant fungi, was developed. Interestingly, metyltetraprole has a very similar structure to other QoIs, azoxystrobin and pyraclostrobin, which do not act on resistant mutants. However, it is unknown how slight structural differences in these inhibitors alter their effectiveness towards fungi with amino acid mutations in the Qo site of Complex III. Therefore, we studied the features of interactions of inhibitors effective towards resistant mutants by quantitatively comparing the interaction profiles of three QoIs at the atomic level. First, we reproduced the binding affinity by the thermodynamic integration (TI) method, which treated explicitly environmental molecules and considered the pseudo-binding pathway. As such, a good correlation (R2 = 0.74) was observed between the binding free energy calculated using the TI method and experimentally observed pIC50 value in 12 inhibitor-target pairs, including wild-type and mutant Complex III in two fungal species, Zymoseptoria tritici and Pyrenophora teres. Trajectory analysis of this TI calculation revealed that the effectiveness against resistant mutant fungi strongly depended on the interaction of constituent parts of the inhibitor disposed near the active center of the target protein. Specifically, the key in the effectiveness against resistant mutant fungi is that the corresponding component part, tetrazolinone moiety of metyltetraprole, traded off Coulomb and van der Waals interactions in response to subtle changes in the binding pose.

Topics: Binding Sites; Drug Resistance, Fungal; Electron Transport Complex III; Fungal Proteins; Fungicides, Industrial; Models, Molecular; Mutation; Protein Structure, Tertiary; Pyrimidines; Saccharomycetales; Strobilurins; Thermodynamics

A nonaqueous micellar electrokinetic capillary chromatography method with indirect LIF was developed for the determination of strobilurin fungicide residues in fruits and vegetables. Hydrophobic CdTe quantum dots (QDs) synthesized in aqueous phase were used as background fluorescent substance. The BGE solution, QD concentration, and separation voltage were optimized to obtain the best separation efficiency and the highest signal intensity. The optimal BGE solution consists of 40 mM phosphate, 120 mM sodium dodecyl sulfate, 15% v/v water and 15% v/v hydrophobic CdTe QDs in formamide, of which apparent pH is 9.5. The optimized separation voltage is controlled as 25 kV. The resultant detection limits of azoxystrobin, kresoxim-methyl, and pyraclostrobin are all 0.001 mg/kg, their linear dynamic ranges are 0.005-2.5 mg/kg, and the recoveries of the spiked samples are 81.7-96.1%, 86.5-95.7%, and 87.3-97.4%, respectively. This method has been proved to be sensitive enough to detect the aforementioned fungicides in fruits and vegetables at the maximum residue limits.

Topics: Chromatography, Micellar Electrokinetic Capillary; Fruit; Fungicides, Industrial; Humans; Hydrophobic and Hydrophilic Interactions; Lasers; Limit of Detection; Methacrylates; Pesticide Residues; Pyrimidines; Quantum Dots; Spectrometry, Fluorescence; Strobilurins; Vegetables

The aim of this study was to determine the behaviour of strobilurin and carbocyamides commonly used in chemical protection of lettuce depending on carefully selected effective microorganisms (EM) and yeast (Y). Additionally, the assessment of the chronic health risk during a 2-week experiment was performed. The statistical method for correlation of physico-chemical parameters and time of degradation for pesticides was applied. In this study, the concentration of azoxystrobin, boscalid, pyraclostrobin and iprodione using liquid chromatography-mass spectrometry (LC-MS/MS) in the matrix of lettuce plants was performed, and there was no case of concentration above maximum residues levels. Before harvest, four fungicides and their mixture with EM (1 % and 10 %) and/or yeast 5 % were applied. In our work, the mixtures of 1%EM + Y and 10%EM + Y both stimulated and inhibited the degradation of the tested active substances. Adding 10%EM to the test substances strongly inhibited the degradation of iprodione, and its concentration decreased by 30 %, and in the case of other test substances, the degradation was approximately 60 %. Moreover, the addition of yeast stimulated the distribution of pyraclostrobin and boscalid in lettuce leaves. The risk assessment for the pesticides ranged from 0.4 to 64.8 % on day 1, but after 14 days, it ranged from 0.0 to 20.9 % for children and adults, respectively. It indicated no risk of adverse effects following exposure to individual pesticides and their mixtures with EM and yeast.

Topics: Aminoimidazole Carboxamide; Aspergillus; Biphenyl Compounds; Carbamates; Chromatography, Liquid; Environmental Monitoring; Fungicides, Industrial; Humans; Hydantoins; Lactobacillales; Lactuca; Methacrylates; Mucor; Niacinamide; Penicillium; Pesticide Residues; Pesticides; Pyrazoles; Pyrimidines; Rhodobacteraceae; Risk Assessment; Saccharomyces cerevisiae; Streptomyces; Strobilurins; Tandem Mass Spectrometry

Greenhouse studies were conducted to evaluate the dissipation rate kinetics and estimate the behavior of selected pesticides after washing, peeling, simmering, and canning of tomato expressed as processing factor (PF). Two varieties (Marissa and Harzfeuer) were treated by six fungicides: azoxystrobin, boscalid, chlorothalonil, cyprodinil, fludioxonil, and pyraclostrobin at single and double dose and risk assessment defined as hazard quotient was performed. The QuEChERS method was used for sample preparation followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The dissipation of fungicides approximately fitted to a first-order kinetic model, with half-life values ranging from 2.49 and 2.67 days (cyprodinil) to 5.00 and 5.32 days (chlorothalonil) for Marissa and Harzfeuer variety, respectively. Results from processing studies showed that treatments have significant effects on the removal of the studied fungicides for both varieties. The PFs were generally less than 1 (between 0.01 and 0.90) and did not depend on variety. The dietary exposure assessed based on initial deposits of application at single and double dose on tomatoes and concentration after each process with PF correction showed no concern to consumer health. Our results would be a useful tool for monitoring of fungicides in tomatoes and provide more understanding of residue behavior and risk posed by these fungicides.

Topics: Carbamates; Chromatography, Liquid; Dioxoles; Food Contamination; Food Handling; Fungicides, Industrial; Half-Life; Humans; Methacrylates; Nitriles; Pesticide Residues; Pyrazoles; Pyrimidines; Pyrroles; Risk; Risk Assessment; Solanum lycopersicum; Strobilurins; Tandem Mass Spectrometry

Early blight, caused by the fungus. Nei's gene diversity index for the Swedish populations of. Genetic diversity was relatively high among isolates of

Topics: Alternaria; Amplified Fragment Length Polymorphism Analysis; Carbamates; Cytochromes b; DNA, Fungal; Drug Resistance, Fungal; Fungicides, Industrial; Genetic Variation; Genotype; Methacrylates; Mitochondria; Plant Diseases; Pyrazoles; Pyrimidines; Solanum tuberosum; Strobilurins; Sweden

The extreme specificity of immunoaffinity chromatography (IAC) columns coupled to the high sensitivity of ion mobility spectrometry (IMS) measurements makes this combination really useful for rapid, selective, and sensitive determination of a high variety of analytes in different samples. The capabilities of the IAC-IMS coupling have been highlighted under three different scenarios: (i) multiclass residue analysis using a single IAC column, (ii) multiclass residue analysis using stacked IAC columns, and (iii) isomer analysis. In the first case, the determination of three strobilurin fungicides - azoxystrobin, picoxystrobin, and pyraclostrobin - in water and strawberry juice was considered, obtaining limits of quantification (LOQs) from 11 to 63μgL(-1). Recoveries from 96 to 106% for water, and from 67 to 104% for strawberry juice were obtained. In the second case, anilinopyrimidine compounds, including two analytes with similar drift time, were selectively retained in different IAC columns and analyzed after independent elution in commercial wine samples by IMS. LOQ values of 16, 14 and 12μgL(-1) were obtained for pyrimethanil, mepanipyrim, and cyprodinil, respectively. The obtained recoveries for wine samples spiked with 25 and 100μgL(-1) were from 82 to 123%. Additionally, the stacked IAC columns concept was applied to the separation of Z and E isomers of azoxystrobin that were selectively retained in specific IAC columns and quantified by IMS. Recoveries between 91 and 94% were obtained for both isomers in water samples.

Topics: Acrylates; Carbamates; Chromatography, Affinity; Fragaria; Fruit and Vegetable Juices; Fungicides, Industrial; Methacrylates; Pyrazoles; Pyridines; Pyrimidines; Sensitivity and Specificity; Stereoisomerism; Strobilurins; Water; Wine

Calonectria (formerly Cylindrocladium) infection of pot azalea (Rhododendron simsii Planch) is an important disease problem in which usually one or two of the four plants per pot show progressing leaf and especially stem lesions, leading to mortality of the respective plant and rendering the pot unmarketable. This may occur in a later stage of the growing season, leading to significant commercial losses. The main objective of this study was to test a range of fungicides for their efficacy against this pathogen. To test the fungicides, a bioassay was first developed in which mycelium and conidiospores of the pathogen were produced on Potato Dextrose Agar, blended in water, and dilutions of the resulting suspension inoculated at the base of 11-week-old cuttings three weeks after they had been trimmed. Disease progression was monitored up to 7 weeks post inoculation and a disease index on a scale of 0 to 3 was established. In the actual efficacy trial, the following fungicides (with corresponding active ingredient(s)) were tested as preventive treatments: Topsin M 70 WG (thiophanate-methyl), Sporgon (prochloraz), Signum (boscalid+pyraclostrobin), Switch (cyprodinyl+fludioxonil), Flint 50WG (trifloxystrobin), Ortiva Top (azoxystrobin+difenoconazole) and Fungaflor (imazalil). Disease expression started after about 2 weeks, increased approximately 1 index level, and leveled off 5 weeks after inoculation. The best control was observed with Sporgon, Ortiva Top and Signum. Switch produced intermediate effects and insufficient control was observed with Topsin, Flint and Fungaflor. These results explain why specific standard fungicide treatments, such as those with Topsin, fail to control the disease, while they can be effective against a different Calonectria species such as C. pseudonaviculata, the cause of boxwood blight.

Topics: Acetates; Carbamates; Dioxolanes; Fungicides, Industrial; Hypocreales; Imidazoles; Imines; Methacrylates; Plant Diseases; Pyrazoles; Pyrimidines; Rhododendron; Strobilurins; Triazoles

Agricultural fungicide application has increased tenfold since 2005 in the United States. Active ingredients and formulations of strobilurin fungicides at environmentally relevant concentrations cause mortality to larval and metamorph amphibians; however, little is known about chronic exposure effects in amphibians. We exposed larval amphibians (Bufo cognatus) throughout metamorphosis to the common fungicide formulations Headline(®), Stratego(®), Quilt(®), and a control to determine effects on development and growth. Formulations were tested at 1.7, 50, and 400 μg/L of the active strobilurin ingredient for Headline(®), Stratego(®), and Quilt(®), respectively. Fungicide exposure did not affect body mass or snout-vent length at metamorphosis. However, exposure to Headline(®) at 1.7 μg/L increased the development rate of tadpoles by approximately 5 days compared to the control, an effect not observed for Stratego(®) and Quilt(®). Stratego(®) also caused approximately 35 % cumulative mortality. Results from the experiment suggest that chronic effects of strobilurin fungicides on development, growth, and mortality to B. cognatus are apparent at environmentally relevant concentrations.

Topics: Acetates; Animals; Body Weight; Bufonidae; Carbamates; Dose-Response Relationship, Drug; Drug Combinations; Female; Fungicides, Industrial; Larva; Male; Metamorphosis, Biological; Methacrylates; Mortality; Pyrazoles; Pyrimidines; Strobilurins; Toxicity Tests, Chronic; Triazoles; Water Pollutants, Chemical

The changes of imidacloprid, pyraclostrobin, azoxystrobin and fipronil residues were studied to investigate the carryover of pesticide residues in winter jujube during paste processing. A multi-residue analytical method for winter jujube was developed based on the QuEChERS approach. The recoveries for the pesticides were between 87.5% and 116.2%. LODs ranged from 0.002 to 0.1 mg kg(-1). The processing factor (Pf) is defined as the ratio of pesticide residue concentration in the paste to that in winter jujube. Pf was higher than 1 for the removal of extra water, and other steps were generally less than 1, indicating that the whole process resulted in lower pesticide residue levels in paste. Peeling would be the critical step for pesticide removal. Processing factors varied among different pesticides studied. The results are useful to address optimisation of the processing techniques in a manner that leads to considerable pesticide residue reduction.

Topics: Carbamates; Food Analysis; Food Contamination; Food Handling; Imidazoles; Insecticides; Methacrylates; Molecular Structure; Neonicotinoids; Nitro Compounds; Pesticide Residues; Pyrazoles; Pyrimidines; Strobilurins; Ziziphus

A new assay of micellar electrokinetic capillary chromatography with sweeping was developed to determine azoxystrobin, kresoxim-methyl and pyraclostrobin in fruits and vegetables. The key factors affecting resolution and peak height were studied and the optimum conditions were obtained for separation and enrichment. The running buffer consisted of 40 mM borate, 25 mM sodium dodecyl sulfate and 15% acetonitrile, and its pH was adjusted to 8.4. The sample was injected for 677 nL and the separation voltage was 25 kV. Under the optimum conditions, the enrichment factors of azoxystrobin, kresoxim-methyl and pyraclostrobin were 861, 550 and 403; the linear dynamic ranges were all 0.01-5.0 mg/L; the limits of detection were 0.002, 0.001 and 0.002 mg/kg; the recoveries of spiked samples were 85.1-98.5%, 87.5-97.0% and 89.1-99.1%, respectively. The assay can meet the requirement of maximum residue limits for these three strobilurin fungicides, and has been applied for determining their residues in fruits and vegetables.

Topics: Acetonitriles; Carbamates; Chromatography, Micellar Electrokinetic Capillary; Fruit; Fungicides, Industrial; Hydrogen-Ion Concentration; Limit of Detection; Methacrylates; Pesticide Residues; Phenylacetates; Pyrazoles; Pyrimidines; Reproducibility of Results; Strobilurins; Vegetables

An LC-MS/MS method was developed for the simultaneously determination of seven strobilurin fungicide residues in Chinese herbs. The strobilurin fungicides include Z-metominostrobin, kresoxim-methyl, dimoxystrobin, picoxystrobin, pyraclostrobin, azoxystrobin and trifloxystrobin. The sample was extracted with ethyl acetate and cleaned-up by an amino SPE column. The seven strobilurin fungicide residues were separated on a C18 column with gradient elution of 1.0 per thousand formic acid and methanol as mobile phases, and detected by ESI-MS in positive ion and selective reaction monitoring (SRM) mode. External standard method was used to the quantification with good linear relationships (r > or = 0. 996). The LOQs were 2 micro g/kg for dimoxystrobin, picoxystrobin and trifloxystrobin, 4 mciro g/kg for pyraclostrobin and azoxystrobin, 10 micro g/kg for Z-metominostrobin and kresoxim-methyl. The recoveries were from 60.4% to 110% with the RSDs between 1.2% and 17%. The developed method is suitable for the determination and confirmation of the seven strobilurin fungicide residues in the three of Eight Zhes ( Ophiopogon japonicus (Thunb.), Scrophularia ningpoensis Hemsl. and Corydalis yanhusuo W T Wang).

Topics: Acetates; Acrylates; Carbamates; Chromatography, Liquid; Drug Contamination; Drug Residues; Drugs, Chinese Herbal; Fungicides, Industrial; Imines; Methacrylates; Phenylacetates; Pyrazoles; Pyridines; Pyrimidines; Strobilurins; Tandem Mass Spectrometry

To provide an assessment of the occurrence of fungicides in water resources, the US Geological Survey used a newly developed analytical method to measure 33 fungicides and an additional 57 current-use pesticides in water samples from streams, ponds, and shallow groundwater in areas of intense fungicide use within three geographic areas across the United States. Sampling sites were selected near or within farms using prophylactic fungicides at rates and types typical of their geographic location. At least one fungicide was detected in 75% of the surface waters and 58% of the groundwater wells sampled. Twelve fungicides were detected including boscalid (72%), azoxystrobin (51%), pyraclostrobin (40%), chlorothalonil (38%) and pyrimethanil (28%). Boscalid, a carboxamide fungicide registered for use in the US in 2003, was detected more frequently than atrazine and metolachlor, two herbicides that are typically the most frequently occurring pesticides in many large-scale water quality studies. Fungicide concentrations ranged from less than the method detection limit to approximately 2000 ngL(-1). Currently, limited toxicological data for non-target species exists and the environmental impacts are largely unknown. The results of this study indicate the importance of including fungicides in pesticide monitoring programs, particularly in areas where crops are grown that require frequent treatments to prevent fungal diseases.

Topics: Biphenyl Compounds; Carbamates; Environmental Monitoring; Fungicides, Industrial; Groundwater; Idaho; Maine; Methacrylates; Niacinamide; Nitriles; Pyrazoles; Pyrimidines; Strobilurins; Water Pollutants, Chemical; Wisconsin