Concentrations Of Azoxystrobin Research Articles

Population Diversity and Sensitivity to Azoxystrobin of Alternaria brassicicola in New York State.

Alternaria brassicicola is the causal agent of Alternaria leaf spot, a common disease of brassica crops in New York State. New York isolates of A. brassicicola were collected from a variety of brassica crops and locations to evaluate the population diversity and screen for fungicide sensitivity. Isolates were genotyped for 10 microsatellite loci and assayed for sensitivity to azoxystrobin, a quinone outside inhibitor fungicide. The New York State population of A. brassicicola was found to have high levels of genotypic diversity and the population was found to be in linkage disequilibrium. Based on in vitro assays, the effective concentrations of azoxystrobin reducing spore germination by 50% ranged from 0.22 to 14.12 μg/ml. In order to confirm the sensitivity of 47 isolates to azoxystrobin, the cytb gene was characterized and sequenced to determine whether any of the mutations known to confer resistance to azoxystrobin were present. The mutations F129L, G137R, and G143A were not detected in the isolates studied.

Pesticide drift from aircraft applications with conical nozzles and electrostatic system

ABSTRACT: Despite all advances obtained with the pesticide use worldwide and in Brazilian agriculture, there is still a lack of technologies for agricultural aircrafts. The objective of this study was to evaluate the drift produced by the use of conical nozzles and electrostatic system in aircraft application. The experimental design was completely randomized with a factorial arrangement and four replications. Treatments included two spraying equipment: electrostatic system with 5L ha-1 of spray volume and conical nozzle with 15 and 20L ha-1. In all treatments, azoxystrobin fungicide was used at a dose of 100g a.i. ha-1 and paraffinic mineral oil at a dose of 0.5% v.v. Volume median diameter (VMD) and droplet density were estimated using water sensitive paper. Evaluations of drift distance were performed with glass collectors distributed horizontally on the soil surface, 50m before the application band, at the application site and 12,5, 25, 50, 75, 100, 150, 200 and 300m after the application site, along the wind direction. Azoxystrobin concentration in glasses were quantified by UHPLC-MS/MS. Results indicated that the drift distance can reach more than 300 meters away from the application site, with variable concentrations according to the equipment used. Electrostatic system reduced drift when compared to hydraulic conical nozzles.

Identification of QoI fungicide-resistant genotypes of the wheat pathogen Zymoseptoria tritici in Algeria

Septoria tritici blotch caused by Zymoseptoria tritici is currently one of the most damaging diseases on bread and durum wheat crops worldwide. A total of 120 monoconidial isolates of this fungus were sampled in 2012 from five distinct geographical locations of Algeria (Guelma, Annaba, Constantine, Skikda and Oran) and assessed for resistance to Quinone outside Inhibitors (QoI), a widely used class of fungicides for the control of fungal diseases of wheat. Resistance was screened using a mismatch PCR assay that identified the G143A mitochondrial cytochrome b substitution associated with QoI resistance. The isolates were QoI-sensitive, since all possessed the G143 wild-type allele, except for three isolates (two from Guelma and one from Annaba), which had fungicide resistance and possessed the A143 resistant allele. QoI resistance was confirmed phenotypically using a microplate bioassay in which the resistant isolates displayed high levels of half-maximal inhibitory azoxystrobin concentrations (IC 50 s) when compared to sensitive reference isolates. Genetic fingerprinting of all isolates with microsatellite markers revealed that the three resistant isolates were distinct haplotypes, and were are not genetically distinguishable from the sensitive isolates. This study highlights QoI-resistant genotypes of Z. tritici in Algeria for the first time, and proposes a management strategy for QoI fungicide application to prevent further spread of resistance across the country or to other areas of Northern Africa.

Dissipation and Residue of Azoxystrobin in Tomatoes and Soil Using Gas Chromatography with Tandem Mass Spectrometry

The analytical technique for the determination of azoxystrobin in tomato and soil was obtained by gas chromatography with tandem mass spectrometry (GC-MS/ MS), and its dissipation fate was also investigated under field conditions. Azoxystrobin residues in tomato and soil were extracted with ethylacetate+cyclohexane extraction and followed by the dispersive-SPE purification. The average recoveries in tomatoes and soils at different spiked concentrations (0.1, 0.5 and 1.0 mg/kg) ranged from 86.16% to 105.47% with RSDs from 6.8% to 12.3%. The LOD ranged from 0.003 μg/kg to 0.004 μg/kg, and LOQ ranged from 0.009 μg/kg to 0.012 μg/kg. This developed methodology was also used to investigate the residues and dissipation of azoxystrobin in tomatoes and soil under the field conditions. The initial azoxystrobin concentrations in tomato fruits in Henan province and in Zhejiang province were 0.494 mg/kg and 0.638 mg/kg with half-lives of 9.9 days and 11.5 days, respectively. Concentrations were reduced by more than 50% at 10 days after application for both sample sets. Initial azoxystrobin concentrations in soil were 1.747 mg/kg and 1.845 mg/kg in Henan province and in Zhejiang province with half-lives of 8.6 days and 7.7 days, respectively.

The influence of effective microorganisms (EM) and yeast on the degradation of strobilurins and carboxamides in leafy vegetables monitored by LC-MS/MS and health risk assessment.

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.

Sensitivity of Erysiphe necator and Plasmopara viticola in Virginia to QoI Fungicides, Boscalid, Quinoxyfen, Thiophanate Methyl, and Mefenoxam.

The sensitivity of downy mildew (DM, Plasmopara viticola) and powdery mildew (PM, Erysiphe necator) of grape (Vitis sp.) to commonly used nondemethylation inhibitor, single-site fungicides in and near Virginia was determined from 2005 to 2007, with more limited additional sampling in subsequent years. In grape leaf disc bioassays, 92% of the P. viticola isolates were quinone outside inhibitor (QoI, azoxystrobin) resistant but none were resistant to mefenoxam. In all, 82% of the E. necator isolates were QoI resistant. Most of the QoI-resistant P. viticola and E. necator isolates contained >95% of the G143A point mutation, which confers high levels of QoI resistance. In contrast, QoI-sensitive P. viticola isolates contained less than 1% of G143A. In total, 1 of 145 and 14 of 154 QoI-resistant P. viticola and E. necator isolates (able to grow on azoxystrobin concentration ≥1 μg/ml), respectively, contained <1% G143A. In total, 61 E. necator isolates from 23 locations were tested against thiophanate methyl, and the majority grew well on leaf tissue treated with 50 and 250 μg/ml. Through 2012, none of the E. necator isolates were resistant to boscalid and quinoxyfen. However, in 2013, quinoxyfen-resistant E. necator was detected in one vineyard experiencing difficulties with powdery mildew control. No 50% effective concentration value could be calculated but these isolates tolerated labeled rates with only limited inhibition. QoI (E. necator and P. viticola) and benzimidazole (E. necator) resistance were widespread in Virginia, rendering these materials inadvisable for control of these diseases. The practical importance and current distribution of quinoxyfen resistance needs further investigation.

Application Pressure and Carrier Volume Affects the Concentration of Azoxystrobin on Peanut Foliage and in Soil

ABSTRACT Azoxystrobin can be used to manage pod rot of peanuts, and applications are typically made at mid-season or later, when it can be difficult to move the fungicide through the foliage and down into the soil. Spanish peanuts were sprayed with azoxystrobin in 2013 at carrier volumes ranging from 252 to 1038 L ha−1 and pressure ranging from 138 to 552 kPa; and in 2014 virginia peanuts were sprayed with carrier volumes ranging from 131 to 524 L ha−1 and pressure ranging from 138 to 414 kPa. Square root transformed azoxystrobin concentration (√A in ppm) on foliage at carrier volumes &amp;lt; 300 L ha−1 was higher in 2 of 3 experiments (√A averaged 2.4 times higher) with spanish peanuts and 1 of 2 experiments (√A averaged 1.3 times higher) on virginia peanuts, than at volumes ≥ 524 L ha−1. A linear model could be used to describe the negative relationship between carrier volume and (√A) on foliage for all three applications on spanish peanuts. Azoxystrobin concentrations in soil were 3 times higher for carrier volumes &amp;lt; 300 L ha−1 in 2 of 3 experiments on spanish peanuts and were not affected by carrier volume on virginia peanuts, than carrier volumes ≥ 524 L ha−1. However, application pressure of 138 kPa resulted in higher concentrations of azoxystrobin (1.7 times higher) in the soil in 1 of 2 trials than using an application pressure of 515 kPa on virginia peanuts. Foliar concentrations of azoxystrobin on virginia peanuts declined over time and irrigation events. However, soil concentrations of azoxystrobin generally increased between 0 and the first irrigation event for the higher carrier volume (524 L ha−1), but did not change between the first and second irrigation event. Attempts to force azoxystrobin through the peanut canopy with high pressure (414 to 552 kPa), high carrier volume (≥524 L ha−1) or combinations of high pressure and high carrier volumes were unsuccessful at increasing azoxystrobin concentrations in soil compared to more traditional carrier volume and pressure.

Application Pressure and Carrier Volume Affects the Concentration of Azoxystrobin on Peanut Foliage and in Soil

Application Pressure and Carrier Volume Affects the Concentration of Azoxystrobin on Peanut Foliage and in Soil

Fungicide Sensitivity of U.S. Genotypes of Phytophthora infestans to Six Oomycete-Targeted Compounds.

Phytophthora infestans causes potato late blight, an important and costly disease of potato and tomato crops. Seven clonal lineages of P. infestans identified recently in the United States were tested for baseline sensitivity to six oomycete-targeted fungicides. A subset of the dominant lineages (n = 45) collected between 2004 and 2012 was tested in vitro on media amended with a range of concentrations of either azoxystrobin, cyazofamid, cymoxanil, fluopicolide, mandipropamid, or mefenoxam. Dose-response curves and values for the effective concentration at which 50% of growth was suppressed were calculated for each isolate. The US-8 and US-11 clonal lineages were insensitive to mefenoxam while the US-20, US-21, US-22, US-23, and US-24 clonal lineages were sensitive to mefenoxam. Insensitivity to azoxystrobin, cyazofamid, cymoxanil, fluopicolide, or mandipropamid was not detected within any lineage. Thus, current U.S. populations of P. infestans remained sensitive to mefenoxam during the displacement of the US-22 lineage by US-23 over the past 5 years.

Biochemical and physiological responses of Carcinus maenas to temperature and the fungicide azoxystrobin

Research on the effects of thermal stress is currently pertinent as climate change is expected to cause more severe climate-driven events. Carcinus maenas, a recognised estuarine model organism, was selected to test temperature-dependence of azoxystrobin toxicity, a widely applied fungicide. Crabs’ responses were assessed after a 10-d acclimation at different temperatures (5°C, 22°C, and 27°C) of which the last 72h were of exposure to an environmental concentration of azoxystrobin. SOD and GST activities, mitochondrial oxygen consumption rates and protein content, as well as the Coupling Index were determined. The hypothesis proposed that extreme temperatures (5°C and 27°C) and azoxystrobin would affect crabs’ responses. Results showed statistically significant different effects of SOD and all oxygen rates measured promoted by temperature, and that neither 30.3μgL−1 of azoxystrobin nor the combined effect were crab-responsive. Protein content at 5°C was statistically higher when compared with the control temperature (22°C). The Coupling Index revealed both a slight and a drastic decrease of this index promoted by 5°C and 27°C, respectively. Regarding azoxystrobin effects, at 22°C, this index only decreased slightly. However, at extreme temperatures it fell 47% at 5°C and slightly increased at 27°C. Results provided evidence that crabs’ responses to cope with low temperatures were more effective than their responses to cope with high temperatures, which are expected in future climate projections. Moreover, crabs are capable of handling environmental concentrations of azoxystrobin. However, the Coupling Index showed that combined stress factors unbalance crabs’ natural capability to handle a single stressor.

Investigations on fungicide removal from broccoli by various processing methods

The removal of five fungicide residues from the broccoli matrices were achieved by various processing methods. The influence of washing with chlorinated and ozonated water, blanching and cooking on the concentration of azoxystrobin, boscalid, iprodione, metalaxyl, and pyraclostrobin has been studied on the broccoli samples collected from experimental plots over two weeks after the application. The analysis of five pesticides was carried out by gas chromatography with nitrogen-phosphorous and electron capture detection (GC-NPD/ECD) and matrix solid-phase dispersion as the sample preparation method. Fungicides levels in the unprocessed broccoli samples were 0.16–4.34 mg/kg. The washing of the matrices with chlorinated and ozonated water was not as effective as cooking in the removal of residual pesticides. Washing with chlorinated and ozonated water reduced concentration up to 45.9 and 49.0%, respectively. Blanching and cooking decreased residues up to 50 and 87%, respectively. Our results show that the cooking process has a great potential in the process of removing residual pesticides from broccoli.

Chronic aquatic effect assessment for the fungicide azoxystrobin.

The present study examined the ecological effects of a range of chronic exposure concentrations of the fungicide azoxystrobin in freshwater experimental systems (1270-L outdoor microcosms). Intended and environmentally relevant test concentrations of azoxystrobin were 0 µg active ingredient (a.i.)/L, 0.33 µg a.i./L, 1 µg a.i./L, 3.3 µg a.i./L, 10 µg a.i./L, and 33 µg a.i./L, kept at constant values. Responses of freshwater populations and community parameters were studied. During the 42-d experimental period, the time-weighted average concentrations of azoxystrobin ranged from 93.5% to 99.3% of intended values. Zooplankton, especially copepods and the Daphnia longispina group, were the most sensitive groups. At the population level, a consistent no-observed-effect concentration (NOEC) of 1 µg a.i./L was calculated for Copepoda. The NOEC at the zooplankton community level was 10 µg azoxystrobin/L. The principle of the European Union pesticide directive is that lower-tier regulatory acceptable concentrations (RACs) are protective of higher-tier RACs. This was tested for chronic risks from azoxystrobin. With the exception of the microcosm community chronic RAC (highest tier), all other chronic RAC values were similar to each other (0.5-1 µg a.i./L). The new and stricter first-tier species requirements of the European Union pesticide regulation (1107/2009/EC) are not protective for the most sensitive populations in the microcosm study, when based on the higher tier population RAC. In comparison, the Water Framework Directive generates environmental quality standards that are 5 to 10 times lower than the derived chronic RACs.

English

The mobility of azoxystrobin in sandy loam soil was studied under continuous and discontinuous flow conditions in soil columns under laboratory conditions at two application rates (50 and 100 &mu;g), with simulated rainfall of 300 mm. Residues of azoxystrobin in soil and leachate were estimated by gas-liquid chromatography and confirmed by gas chromatography-mass spectrometry. Though maximum concentration of azoxystrobin was found in the top 10 cm layer under both continuous and discontinuous flow conditions but azoxystrobin residues under continuous flow conditions were recorded down to a depth of 15-20 cm and under discontinuous flow conditions residues, were recorded at depths of up to 20 and 25 cm for the single and double dose treatments, respectively. The retention of azoxystrobin residues was greater under continuous flow conditions at the higher dose, whereas a low retention of azoxystrobin residues at the lower dose and under discontinuous flow conditions was observed. The low mobility of azoxystrobin in soil indicated that it represents a low risk to groundwater systems. Leachate fractions were free from azoxystrobin residues. &nbsp; Key words: Leaching, azoxystrobin, sandy loam soil, column, residues.

Integrated assessment of oxidative stress and DNA damage in earthworms (Eisenia fetida) exposed to azoxystrobin

Azoxystrobin has been widely used in recent years. The present study investigated the oxidative stress and DNA damage effects of azoxystrobin on earthworms (Eisenia fetida). Earthworms were exposed to different azoxystrobin concentrations in an artificial soil (0, 0.1, 1, and 10mg/kg) and sampled on days 7, 14, 21, and 28. Superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), glutathione-S-transferase (GST), reactive oxygen species (ROS), and malondialdehyde (MDA) content were measured by an ultraviolet spectrophotometer to determine the antioxidant responses and lipid peroxidation. Single cell gel electrophoresis (SCGE) was used to detect DNA damage in the coelomocytes. Compared with these in the controls, earthworms exposed to azoxystrobin had excess ROS accumulation and greater SOD, POD, and GST activity while the opposite trend occurred for CAT activity. MDA content increased after 14-day exposure, and DNA damage was enhanced with an increase in the concentration of azoxystrobin. In conclusion, azoxystrobin caused oxidative stress leading to lipid peroxidation and DNA damage in earthworms.

ストロビルリン系薬剤耐性マンゴー炭疽病菌&lt;i&gt;Colletotrichum gloeosporioides&lt;/i&gt;の発生

Sensitivity to strobilurin fungicides was tested for 107 isolates of Colletotrichum gloeosporioides, obtained in 2009 and 2010 from mangoes with anthracnose in Okinawa Prefecture, Japan. When isolates were grown on potato dextrose agar containing 1000 ppm of salicylhydroxamic acid and various concentrations of azoxystrobin and kresoxim-methyl, two strains showed a minimal inhibitory concentration of >3000 ppm and were regarded as resistant. The control efficacy of azoxystrobin against two strains was low in a leaf bioassay, and the G143A point mutation in the cytochrome b gene, conferring resistance to strobilurins, was confirmed by PCR-RFLP using restriction enzyme Fnu4HI.

Impact of tricyclazole and azoxystrobin on growth, sporulation and secondary infection of the rice blast fungus, Magnaporthe oryzae

Rice blast, caused by Magnaporthe oryzae B. Couch sp. nov., is one of the most destructive rice diseases worldwide, causing substantial yield losses every year. In Italy, its management is based mainly on the use of two fungicides, azoxystrobin and tricyclazole, that restrain the disease progress. The aim of this study was to investigate and compare the inhibitory effects of the two fungicides on the growth, sporulation and secondary infection of M. oryzae. Magnaporthe oryzae mycelium growth was inhibited at low concentrations of azoxystrobin and relatively high concentrations of tricyclazole, while sporulation was more sensitive to both fungicides and was affected at similarly low doses. Furthermore, infection efficiency of conidia obtained from mycelia exposed to tricyclazole was affected to a higher extent than for conidia produced on azoxystrobin-amended media, even though germination of such conidia was reduced after azoxystrobin treatment. This study presents for the first time detailed azoxystrobin and tricyclazole growth-response curves for M. oryzae mycelium growth and sporulation. Furthermore, high efficacy of tricyclazole towards inhibition of sporulation and secondary infection indicates an additional possible mode of action of this fungicide that is different from inhibition of melanin biosynthesis.

Azoxystrobin과 difenoconazole의 인삼 중 잔류 특성

This study was carried out to elucidate residual characteristics of azoxystrobin and difenoconazole in fresh ginseng. Test pesticides were sprayed onto ginseng both in 2009 for 3-year-old ginseng and in 2010 for 4-year-old ginseng according to their pre-harvest intervals (PHIs). Limit of quantitation (LOQ) of both azoxystrobin and difenoconazole was 0.003 mg/kg. Analytical methods set up for the test pesticides were considered to be suitable for the analysis of their residues in fresh ginseng, considering that their recoveries ranged from 87.58 to 112.79%. Concentration of azoxystrobin in 3-year-old ginseng ranged from 0.004 to 0.011 mg/kg and that in 4-year-old ginseng ranged from 0.007 to 0.016 mg/kg. Amounts of difenoconazole in 3- and 4-year-old ginsengs were from 0.003 to 0.007 and from 0.007 to 0.01 mg/kg, respectively, representing no accumulation effect observed in residue amount between them.

EFFICACY OF AZOXYSTROBIN FUNGICIDE AGAINST SORE SHIN OF SHADE TOBACCO CAUSED BY RHIZOCTONIA SOLANI

Azoxystrobin fungicide was evaluated for efficacy against Rhizoctonia solani, causal agent of tobacco sore shin, in greenhouse and in vitro tests. Azoxystrobin significantly increased root weights and reduced disease ratings compared with untreated controls in 2004 and 2005, and also reduced the percent of the stem girdled in 2005 (not measured in 2004). Some phytotoxicity (observed as flecks) was visible on 1 or 2 leaves of Quadris-treated transplants about 1 week after treatment. Leaves that expanded after treatment did not show symptoms. Activity of azoxystrobin fungicide in vitro was not as effective as might be expected from field observations and greenhouse experiments. Dose– response experiments of R. solani mycelial growth rate on azoxystrobin-amended half-strength Potato dextrose agar measured mycelial growth inhibition of only 30% by 1,000 mg/ ml ai. Salicylhydroxamic acid (SHAM), used to inhibit the alternative oxidase pathway in a number of fungi, was tested at 100 mg/ml SHAM in media to determine the efficacy of azoxystrobin against 2 isolates of R. solani in the absence of the alternative oxidase pathway. In the presence of SHAM, the inhibition of mycelial growth was over the LD50 for all concentrations tested, indicating that R. solani does use an alternative oxidation pathway in vitro. However, the observed inhibition decreased over time; inhibition averaged over all azoxystrobin concentrations was 63.3% after the first 24 hr, 52.0% after 48 hr and only 26.5% during the third–fourth day of exposure (P 5 0.001). It appears that an additional mechanism of alternative oxidation may become active over time in R. solani. Azoxystrobin (Quadris) is registered for management of tobacco blue mold and should be valuable as a transplant band treatment to protect shade-grown tobacco plants from sore shin caused by R. solani. Additional key words: alternative oxidase pathway, Nicotiana tabacum, Quadris, sore shin

Pesticide dissipation curves in peach, pear and tomato crops in Uruguay*

Dissipation curves of azoxystrobin and of the neonicotinoids acetamiprid and thiacloprid in peach; azinphos-methyl and carbaryl in pear and azoxystrobin, chlorfenapyr and chlorpyrifos in high-tunnel tomato crops were studied in the Southern region of Uruguay. An analytical methodology based on solid phase extraction (SPE) and detection by High Performance Liquid Chromatography with Diode Array Detector (HPLC/DAD) was used for acetamiprid and thiacloprid. Coupled SPE and detection by Gas Chromatography with Mass Selective Detector (GC/MSD) was used for the detection of azinphos-methyl, azoxystrobin, carbaryl, chlorfenapyr and chlorpyrifos residues. Curves were modeled mathematically with Solver program of Microsoft Excel®. The best fit for acetamiprid and thiacloprid in peach was achieved with the exponential model (r2=0.961 and 0.944, respectively). In the case of peach fruits there is not a Maximum Residue Limit (MRL) for acetamiprid in the Codex Alimentarius, while 0.5 mg/kg is the value rated for thiacloprid. The MRLs accepted by the European Union (EU) are 0.1 mg/kg for acetamiprid and 0.3 mg/kg for thiacloprid. According to the curves determined in these experiments, thiacloprid residues 10 to 12 days after application (daa) were below the MRLs established by both sources. In the case of acetamiprid, 25 daa would be required, according to the exponential mathematical model, to get residues levels below the MRL values established by the EU. For azinphos methyl in pear, the residues detected were mathematically fitted to an exponential model (r2=0.999). According to it, residue levels under the MRL established by the EU (0.05 mg/kg) are gotten in our conditions in 20 daa. In plastic tunnel tomato chlorfenapyr residues were not detected from 16 daa, having the dissipation curve an exponential trend. In the same condition, there was not a decay of the azoxystrobin concentration during a 24-day trial, being it around 0.40 ± 0.05 mg/kg.

Effects of the fungicide azoxystrobin on Atlantic salmon ( Salmo salar L.) smolt

Atlantic salmon smolts were exposed to three doses of the fungicide azoxystrobin for 4 days, and physiological blood parameters and transcriptional effects in liver and muscle were evaluated in search for potential negative effects. Azoxystrobin exposure mediated up-regulation of catalase, MAPK1 and IGFBP1 in liver tissue. Catalase, transferrin, IGFBP1 and TNFR were up-regulated and CYP1A down-regulated in muscle tissue. Blood parameters glucose, hematocrit, pCO 2, HCO 3 and pH grouped together with transcripts levels of MnSOD, MAPK1, IGFBP1, MAP3K7 and GPx4 in liver of fish exposed to the highest azoxystrobin concentration (352 μg L −1) using principal component analysis (PCA). In muscle, the blood parameters glucose, hematocrit, pCO 2, HCO 3 and pH grouped together with transcript levels of heme oxygenase, thioredoxin, MnSOD, TNFR and MMP9. These results suggest that the fungicide azoxystrobin affects mitochondrial respiration and mechanisms controlling cell growth and proliferation in fish and may have negative effects on juvenile Atlantic salmon.