azoxystrobin and cyprodinil

The aim of this study was to investigate the bioaccessibility of pesticide residues in blueberries (commercial and sample from controlled field trial) from Serbia, involving the presence of a complex food matrix and to assess the potential risk to human health. The presence of nine active substances (azoxystrobin, boscalid, fludioxonil, cyprodinil, pyrimethanil, pyridaben, pyriproxyfen, acetamiprid and thiametoxam) in initial blueberry samples was determined in concentration range from 5.15 μg/kg for thiametoxam to 187 μg/kg for azoxystrobin. Clothianidin, metabolite of thiametoxam, was not detected in any blueberry sample. However, after in vitro digestion, the content of initially detected pesticides residues was significantly decreased or it was below limit of quantification resulting in the total bioaccessibility of about 15%. Azoxystrobin, pyrimethanil and fludioxonil was quantified in digestive juice at concentrations which were about 81%, 37% and 10% less than the inital concentration, respectively. The presence of food matrix during digestion of blueberries even more severely reduced concentration of pesticide residues (total bioaccessibility was about 7%) compared to digestion without the food matrix. Only azoxystrobin was quantified after digestion with food matrix in concentration of 27 μg/kg in sample from controlled field trial and detected in two commercial samples but below the limit of quantification. Furthermore, chronic risk assessment indicated that risk is acceptable for the health of different human subpopulation groups. The current study on pesticides residues, most commonly applied on blueberries, provides for the first time an insight into their bioaccessibility under conditions that mimic physiological environment of human digestive tract.

Topics: Blueberry Plants; Dioxoles; Food Contamination; Fruit; Humans; Pesticide Residues; Pyrimidines; Pyrroles; Serbia; Strobilurins

Anthracnose crown rot of strawberry, caused by Colletotrichum acutatum, is an important disease affecting California nursery and fruit production. Preplant dip treatments of transplants with fludioxonil-cyprodinil or azoxystrobin are industry standards for managing the disease and have been used extensively. Following reports of reduced efficacy of azoxystrobin in the field, high levels of quinone outside inhibitor (QoI) resistance were detected in California isolates of the pathogen. Resistance was associated with the G143A mutation in the cytochrome b gene, similar to a previous report from Florida, and there were no detected fitness penalties in pathogenicity or virulence. Therefore, several alternative fungicides were investigated in laboratory and field studies. Subsequently, the new biofungicide natamycin was identified. Baseline sensitivities of 74 isolates of C. acutatum to natamycin were determined to be unimodal, with a range from 0.526 to 1.996 μg/ml (mean 0.973 μg/ml). Although this toxicity was considerably lower than that of azoxystrobin (using sensitive isolates), fludioxonil, or cyprodinil, dip treatments of transplants with natamycin (at 500 or 1000 mg/liter) were highly effective. Disease severity and plant mortality in field studies with inoculated transplants were reduced to similarly low levels as treatments containing fludioxonil, whereas azoxystrobin failed in inoculations with QoI-resistant isolates of C. acutatum. Fruit yield was also significantly increased by natamycin as compared with the inoculated control. Differences in disease susceptibility were observed among cultivars evaluated, with Monterey and Portola more susceptible than Fronteras. Natamycin has a unique mode of action that is different from other fungicides registered on strawberry and, based on this research, was registered in the United States as a preplant, biofungicide dip treatment of strawberry transplants for management of anthracnose crown rot.

Topics: Antifungal Agents; California; Colletotrichum; Dioxoles; Drug Resistance, Fungal; Fragaria; Fruit; Fungicides, Industrial; Mutation; Natamycin; Plant Diseases; Pyrimidines; Pyrroles; Strobilurins

Postharvest disease is a major factor in the limited shelf life of many fruits and vegetables, and it is often managed using fungicidal spraying or soaking. In this study, we first tested the efficiency of six common fungicides on postharvest head cabbage ( Brassica oleracea var. capitata) against Botrytis cinerea. Afterward, the elimination abilities of these six fungicides on different layers of cabbage heads were examined, and the effects of the household processes on residue removal were evaluated. Results showed that very low contents of residues reached the inner layers and that peeling the three outmost leaves of cabbage could eliminate most of the investigated fungicides. All six fungicides disappeared during washing, stir-frying, or boiling, among which cyprodinil was the easiest to be eliminated. Furthermore, the combined processes reduced the residues below the limits of quantification for all six investigated fungicides, even after 2 days of spraying.

Topics: Aminopyridines; Benzimidazoles; Biodegradation, Environmental; Botrytis; Brassica; Carbamates; Consumer Product Safety; Food Preservation; Fungicides, Industrial; Half-Life; Humans; Kinetics; Nitriles; Pesticide Residues; Plant Leaves; Pyrimidines; Strobilurins; Triazoles

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

In this study, we investigated whether fungicide-induced mutagenesis previously reported in Monilinia fructicola could accelerate genetic changes in field populations. Azoxystrobin and propiconazole were applied to nectarine trees at weekly intervals for approximately 3 months between bloom and harvest in both 2013 and 2014. Fungicides were applied at half-label rate to allow recovery of isolates and to increase chances of sublethal dose exposure. One block was left unsprayed as a control. In total, 608 single-spore isolates were obtained from blighted blossoms, cankers, and fruit to investigate phenotypic (fungicide resistance) and genotypic (simple-sequence repeat [SSR] loci and gene region) changes. In both years, populations from fungicide-treated and untreated fruit were not statistically different in haploid gene diversity (P = 0.775 for 2013 and P = 0.938 for 2014), allele number (P = 0.876 for 2013 and P = 0.406 for 2014), and effective allele number (P = 0.861 for 2013 and P = 0.814 for 2014). Isolates from blossoms and corresponding cankers of fungicide treatments revealed no changes in SSR analysis or evidence for induced Mftc1 transposon translocation. No indirect evidence for increased genetic diversity in the form of emergence of reduced sensitivity to azoxystrobin, propiconazole, iprodione, and cyprodinil was detected. High levels of population diversity in all treatments provided evidence for sexual recombination of this pathogen in the field, despite apparent absence of apothecia in the orchard. Our results indicate that fungicide-induced, genetic changes may not occur or not occur as readily in field populations as they do under continuous exposure to sublethal doses in vitro.

Topics: Ascomycota; DNA Transposable Elements; Fruit; Fungicides, Industrial; Genetic Variation; Genotype; Methacrylates; Mutagenesis; Plant Diseases; Prunus persica; Pyrimidines; Strobilurins; Trees; Triazoles

The level of protection provided by the present environmental risk assessment (ERA) of fungicides in the European Union for fungi is unknown. Therefore, we assessed the structural and functional implications of five fungicides with different modes of action (azoxystrobin, carbendazim, cyprodinil, quinoxyfen, and tebuconazole) individually and in mixture on communities of aquatic hyphomycetes. This is a polyphyletic group of fungi containing key drivers in the breakdown of leaf litter, governing both microbial leaf decomposition and the palatability of leaves for leaf-shredding macroinvertebrates. All fungicides impaired leaf palatability to the leaf-shredder Gammarus fossarum and caused structural changes in fungal communities. In addition, all compounds except for quinoxyfen altered microbial leaf decomposition. Our results suggest that the European Union’s first-tier ERA provides sufficient protection for the tested fungicides, with the exception of tebuconazole and the mixture, while higher-tier ERA does not provide an adequate level of protection for fungicides in general. Therefore, our results show the need to incorporate aquatic fungi as well as their functions into ERA testing schemes to safeguard the integrity of aquatic ecosystems.

Topics: Amphipoda; Animals; Aquatic Organisms; Benzimidazoles; Carbamates; Ecosystem; European Union; Fungi; Fungicides, Industrial; Methacrylates; Plant Leaves; Pyrimidines; Quinolines; Risk Assessment; Strobilurins; Triazoles; Water Pollutants, Chemical

A novel microextraction technique combining magnetic solid-phase microextraction (MSPME) with ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) to determine four fungicides is presented in this work for the first time. The main factors affecting the extraction efficiency were optimized by the one-factor-at-a-time approach and the impacts of these factors were studied by an orthogonal design. Without tedious clean-up procedure, analytes were extracted from the sample to the adsorbent and organic solvent and then desorbed in acetonitrile prior to chromatographic analysis. Under the optimum conditions, good linearity and high enrichment factors were obtained for all analytes, with correlation coefficients ranging from 0.9998 to 1.0000 and enrichment factors ranging 135 and 159 folds. The recoveries for proposed approach were between 98% and 115%, the limits of detection were between 0.02 and 0.04 μg L(-1) and the RSDs changed from 2.96 to 4.16. The method was successfully applied in the analysis of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) in environmental water samples. The recoveries for the real water samples ranged between 81% and 109%. The procedure proved to be a time-saving, environmentally friendly, and efficient analytical technique.

Topics: Acetates; Acetonitriles; beta-Cyclodextrins; Chromatography, High Pressure Liquid; Fungicides, Industrial; Imines; Ionic Liquids; Liquid Phase Microextraction; Magnesium Compounds; Magnetic Phenomena; Methacrylates; Nitriles; Pyrimidines; Silicon Compounds; Solid Phase Microextraction; Solvents; Strobilurins; Water Pollutants, Chemical

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

In-package nonthermal plasma (NTP) technology is a novel technology for the decontamination of foods and biological materials. This study presents the first report on the potential of the technology for the degradation of pesticide residues on fresh produce. A cocktail of pesticides, namely azoxystrobin, cyprodinil, fludioxonil and pyriproxyfen was tested on strawberries. The concentrations of these pesticides were monitored in priori and post-plasma treatment using GC-MS/MS. An applied voltage and time dependent degradation of the pesticides was observed for treatment voltages of 60, 70 and 80 kV and treatment durations ranging from 1 to 5 min, followed by 24h in-pack storage. The electrical characterisation revealed the operation of the discharge in a stable filamentary regime. The discharge was found to generate reactive oxygen and excited nitrogen species as observed by optical emission spectroscopy.

Topics: Dioxoles; Electrochemical Techniques; Food Contamination; Fragaria; Fruit; Fungicides, Industrial; Gas Chromatography-Mass Spectrometry; Methacrylates; Ozone; Pesticide Residues; Pyridines; Pyrimidines; Pyrroles; Strobilurins; Tandem Mass Spectrometry

Although there is some evidence regarding the effect of solarization and biosolarization on pesticide degradation, information is still scarce. The aim of this study was to determine the effect of these disinfection techniques on the degradation of eight fungicides (azoxystrobin, kresoxin methyl, tebuconazole, hexaconazole, triadimenol, cyprodinil, pyrimethanil and fludioxonil) commonly used in pepper crops under greenhouse cultivation. Seventy-five 17-L pots filled with clay-loam soil were placed in a greenhouse during the summer season and then contaminated with the studied fungicides. Treatments consisted of different disinfection treatments, including a control without disinfection, solarization and biosolarization. For the solarization and biosolarization treatments, low-density polyethylene film was used as cover. Five pots per treatment were sampled periodically up to 90d after the beginning of each treatment and fungicide residues were analyzed by GC/MS. The results showed that both solarization and biosolarization enhanced fungicide dissipation rates with regard to the control treatment, an effect which was attributed to the increased soil temperature. Most of the fungicides studied showed similar behavior under solarization and biosolarization conditions. However, triadimenol was degraded to a greater extent in the biosolarization than in the solarization treatment, while fludioxonil behaved in the opposite way. The results confirm that both solarization and biosolarization contribute to pesticide dissipation and can therefore be considered alongside other soil disinfection techniques, as a bioremediation tool for pesticide-polluted soils.

Topics: Dioxoles; Environmental Restoration and Remediation; Fungicides, Industrial; Hot Temperature; Methacrylates; Phenylacetates; Photochemical Processes; Pyrimidines; Pyrroles; Soil; Soil Pollutants; Strobilurins; Triazoles

The disappearance of azoxystrobin, pyrimethanil, cyprodinil, and fludioxonil on tomatoes in greenhouse was studied. At the preharvest interval, except for cyprodinil, the pesticide residues were below the MRL fixed in Italy. The mechanism of disappearance studied with model systems shows that the decrease in residues was due to codistillation and photodegradation in pyrimethanil, to photodegradation in fludioxonil, and to evaporation and codistillation in cyprodinil. Azoxystrobin residues were stable during all experiments.

Topics: Acrylates; Agriculture; Dioxoles; Fungicides, Industrial; Methacrylates; Pesticide Residues; Photochemistry; Pyrimidines; Pyrroles; Solanum lycopersicum; Strobilurins; Sunlight