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The leaching loss and movement of pesticides need to be minimized to safeguard the aquatic environment and human health. In a laboratory study, the changes in the leaching and downward movement behavior of boscalid fungicide were examined in soil (Typic Hapludoll) columns (0–30 cm) receiving no amendment (control) or with the application of farmyard manure (FYM) and pine needle biochar (PNB) in surface (0–15 cm) soil @ 5 t ha−1. No boscalid residues (<0.01 µg mL−1) were detected in the leachate under any treatment. Both FYM and PNB were effective in limiting the movement of boscalid in soil compared to control. FYM maintained the highest boscalid concentration (1.41 µg g−1) in the top (0–2.5 cm) soil while in PNB treated soil the highest sorbed boscalid (0.58 µg g−1) could accumulate at 2.5–5.0 cm soil depth. The depth-wise distribution of the boscalid concentration in soil could be well predicted by third order polynomial equations (R2 value = 0.929 to 1.000, all significant at p ≤ 0.01). The FTIR spectra show that the boscalid retention onto these amendments was through H-bonding and π–π interactions. As compared to FYM, the PNB had a relatively lower proportion of soluble- and desorbed-boscalids but a higher proportion of irreversibly sorbed boscalid and appeared to be an effective organic amendment for the areas prone to high surface run-off. [ABSTRACT FROM AUTHOR]

ABSTRACT Synthesis of ZIF‐8 mainly uses zinc nitrate hexahydrate (Zn(NO3)2.6H2O) as the zinc source. Zn (NO3)2.6H2O is flammable, explosive, and highly corrosive, posing a threat to human health. It also requires a molar ratio of 2‐methylimidazole to zinc source greater than 20, resulting in increased costs. In this work, a pH‐sensitive controlled‐release nano‐capsule of fungicide, ZIF‐8@Boscalid, was established using green zinc sources (zinc sulfate and zinc acetate) and was prepared based on metal–organic framework (ZIF‐8) for higher antifungal effect and low bio‐toxicity. The loading ratio is as high as 34%. In addition, the release of fungicide Boscalid showed pH‐sensitive response due to the weak acidic group in the ZIF structure, in which the rate of release was more rapid under acid condition (< 5). Cumulative release rates of the ZIF‐8(A)@Boscalid system and ZIF‐8(S)@Boscalid system were 76.15% and 86.22%, respectively. Meanwhile, the antifungal effect of ZIF‐8@Boscalid was 1.5 times more of that commercially available product on CI‐8 at the concentration of 300 mg/L, and the antibacterial activity values of the ZIF‐8(A)@Boscalid system and ZIF‐8(S)@Boscalid system against CJ‐8 were 84.54% and 78.65%, respectively. Furthermore, the obtained ZIF‐8@Boscalid system using the method described in this article exhibited certain UV resistance. Thus, this work not only proves that ZIF‐8@Boscalid could be used as nanoparticles platform for smart control over CJ‐8 but also has great potential effective utilization of Boscalid and achieving sustained release. [ABSTRACT FROM AUTHOR]

Fungal plant pathogens have posed a significant threat to crop production. However, the large-scale application of pesticides is associated with possible risks for human health and the environment. Boscalid is a widely used fungicide, consistently implemented for the management of significant plant pathogens. Conventionally, the detection and determination of boscalid residues is based on chromatographic separations. In the present study, a Bioelectric Recognition Assay (BERA)-based experimental approach combined with MIME technology was used, where changes in the electric properties of the membrane-engineering cells with anti-boscalid antibodies were recorded in response to the presence of boscalid at different concentrations based on the maximum residue level (MRL) for lettuce. The membrane-engineering Vero cells with 0.5 μg/mL of antibody in their surface were selected as the best cell line in combination with the lowest antibody concentration. Furthermore, the biosensor was tested against another fungicide in order to prove its selectivity. Finally, the BERA cell-based biosensor was able to detect the boscalid residue, below and above the MRL, in spiked lettuce leaf extracts in an entirely distinct and reproducible manner. This study indicates that the BERA-based biosensor, after further development and optimization, could be used for the routine, high-throughput detection of boscalid residue in lettuce, and not only that. [ABSTRACT FROM AUTHOR]

There is a growing concern that chronic exposure to fungicides contributes to negative effects on honey bee development, life span, and behavior. Field and caged‐bee studies have helped to characterize the adverse outcomes (AOs) of environmentally relevant exposures, but linking AOs to molecular/cellular mechanisms of toxicity would benefit from the use of readily controllable, simplified host platforms like cell lines. Our objective was to develop and optimize an in vitro‐based mitochondrial toxicity assay suite using the honey bee as a model pollinator, and the electron transport chain (ETC) modulators boscalid and pyraclostrobin as model fungicides. We measured the effects of short (~30 min) and extended exposures (16–24 h) to boscalid and pyraclostrobin on AmE‐711 honey bee cell viability and mitochondrial function. Short exposure to pyraclostrobin did not affect cell viability, but extended exposure reduced viability in a concentration‐dependent manner (median lethal concentration = 4175 µg/L; ppb). Mitochondrial membrane potential (MMP) was affected by pyraclostrobin in both short (median effect concentration [EC50] = 515 µg/L) and extended exposure (EC50 = 982 µg/L) scenarios. Short exposure to 10 and 1000 µg/L pyraclostrobin resulted in a rapid decrease in the oxygen consumption rate (OCR), approximately 24% reduction by 10 µg/L relative to the baseline OCR, and 64% by 1000 µg/L. Extended exposure to 1000 µg/L pyraclostrobin reduced all respiratory parameters (e.g., spare capacity, coupling efficiency), whereas 1‐ and 10‐µg/L treatments had no significant effects. The viability of AmE‐711 cells, as well as the MMP and cellular respiration were unaffected by short and extended exposures to boscalid. The present study demonstrates that the AmE‐711‐based assessment of viability, MMP, and ETC functionality can provide a time‐ and cost‐effective platform for mitochondrial toxicity screening relevant to bees. Environ Toxicol Chem 2024;43:976–987. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Early blight (EB), caused by the dominant species Alternaria alternata, is a major global disease of tomato (Solanum lycopersicum L.; Solanaceae) reducing the vegetative organs and causing losses. Sustainable food production mainly depends on the rational use of chemical fertilizers and fungicides in integrated plant disease management. Hence, the fungicidal activity of ortivatop® (azoxystrobin + difenoconazole), Signum WG 33.4% (pyraclostrobin + boscalid) and daconyl SC 72% (chlorothalonyl) was evaluated against tomato EB disease under field conditions. Two experiments were conducted during the cropping seasons from 2019 to 2020 in three regions. The experimental design was a randomized block with 4 replications using Ortivatop® (ORT) at three doses of -900, -1100 and -1300 ml. ha−1 (recommended doses of the company), daconyl (DAC) 2 l. ha−1 and Signum (SIG) 0.5 l. ha−1. The findings showed that ORT-1300 (20.6%) and DAC (22.7%) resulted in the lowest EB disease severity, followed by SIG (25.7%), ORT-1100 (26.9%) and ORT-900 (31.7), in contrast to 59.1% of the control. Compared with treatment without fungicide, all fungicides reduced the AUDPC (area under disease progress curve) and provided an increase in productivity. ORT-1300 ml ha−1 showed the greatest reduction in AUDPC by up to 70% and increased tomato yield by threefold more than the untreated control. Therefore, the current study suggests that foliar spraying with ORT-1300 ml. ha−1 at all three growth stages, is an ideal solution for EB disease management. [ABSTRACT FROM AUTHOR]

In the present study, the photocatalytic oxidation and detoxification of aqueous matrices contaminated with boscalid using g-C3N4 catalyst and UV-A light was investigated. The UV-A/g-C3N4 process was found to achieve higher than 83% removal of boscalid in both matrices, with h+ and O 2 • − being the main species. UHPLC-HRMS analysis allowed the identification of five TPs, while the main degradation pathways involved hydroxylation, cyclization, and dechlorination. Scenedesmus rubescens microalgae species was exposed to boscalid solutions and lake water spiked with the fungicide before the photocatalytic treatment and inhibition in the growth rate was observed. An increase in the toxicity was also observed during the first stages of the treatment. The results from the in silico study correlate with the observed evolution of ecotoxicity during the application of the process, as some of the identified TPs were found to be toxic or very toxic for aquatic organisms. However, prolonged application of the process can lead to detoxification. It was also observed that the g-C3N4 catalyst can retain its photochemical stability and activity after at least three cycles. However, a slight decrease in the activity was observed when repeated another two times. This study demonstrated that the suggested photocatalytic process can both decrease the harmful effects of boscalid as well as effectively lower its concentration in water. [ABSTRACT FROM AUTHOR]

Cucumber leaf spot (CLS), caused by Corynespora cassiicola, is a serious disease of greenhouse cucumbers. With frequent use of existing fungicides, C. cassiicola has developed resistance to some of them, with serious implications for the control of CLS in the field. With a lack of new fungicides, it is necessary to use existing fungicides for effective control. Therefore, this study monitored the resistance of C. cassiicola to three commonly used and effective fungicides, boscalid, trifloxystrobin, and carbendazim, from 2017 to 2021. The frequency of resistance to boscalid showed an increasing trend, and the highest frequency was 85.85% in 2020. The frequency of resistance to trifloxystrobin was greater than 85%, and resistance to carbendazim was maintained at 100%. Among these fungicides, strains with multiple resistance to boscalid, trifloxystrobin, and carbendazim were found, accounting for 32.00, 25.25, 33.33, 43.06, and 37.24%, respectively. Of the strains that were resistant to boscalid, 87% had CcSdh mutations, including seven genotypes: B-H278L/Y, B-I280V, C-N75S, C-S73P, D-D95E, and D-G109V. Also, six mutation patterns of the Ccß-tubulin gene were detected: E198A, F167Y, E198A&M163I, E198A&F167Y, M163I&F167Y, and E198A&F200C. Detection of mutations of the CcCytb gene in resistant strains showed that 98.8% were found to have only the G143A mutation. A total of 27 mutation combinations were found and divided into 14 groups for analysis. The resistance levels differed according to genotype. The development of genotypes showed a complex trend, increasing from 4 in 2017 to 13 in 2021 and varying by region. Multiple fungicide resistance is gradually increasing. Therefore, it is necessary to understand the types of mutations and the trend of resistance to guide the use of fungicides to achieve disease control. [ABSTRACT FROM AUTHOR]

Gray mold is a common and severe disease that affects strawberry production and storage. To clarify the occurrence and mechanism of Botrytis cinerea in strawberry resistance to boscalid [2-Chloro-N-(4'-chlorobiphenyl-2-yl) nicotinamide], a widely used fungicide, 137 isolates of Botrytis cinerea in strawberry were collected from Beibei, Xiema, and Changshou of Chongqing by random sampling method in 2021–2022 and monitored for resistance in the field by the discriminatory dosage method. The succinate dehydrogenase (SDH) related gene of 55 resistant strains was sequenced, and molecular docking was used to predict the binding mode of boscalid to wild-type and mutant SDH of B. cinerea. The results showed that the resistance frequency of B. cinerea to boscalid in Chongqing was 93.43%. Mutation sites on the B subunit of SDH were found in 45 of the 55 resistant strains, with three primary mutation types, P225F, N230I, and H272R, responsible for 43.6%, 16.4%, and 21.8% of mutations, respectively. Out of the 55 resistant strains, five were found to have mutation sites on the C subunit of SDH. Only one mutation type, G85A+I93V+M158V+V168I, was observed in these strains, where four amino acids were mutated simultaneously. However, no mutation sites were detected in the remaining five resistant strains. Molecular docking results predicted that the P225F mutation prevented boscalid from entering the binding pocket, which affects the formation of hydrogen bonds and other interaction forces and ultimately hinders the ability of boscalid to bind to SDH. The H272R mutation narrows the cavity bottom of the binding pocket and rotates part of the boscalid chemical bond, while the N230I mutation has no effect on boscalid binding. This study clarified the occurrence and mechanism of boscalid resistance in B. cinerea in the Chongqing region, and the results provide an experimental data for formulating strawberry gray mold management strategies and also provide some insights for the development of succinic dehydrogenase inhibitors (SDHIs) fungicides. [ABSTRACT FROM AUTHOR]

Laboratory mutants of Sclerotinia sclerotiorum (Lib) de Bary, resistant to boscalid, have been extensively characterized. However, the resistance situation in the lettuce field remains largely elusive. In this study, among the 172 S. sclerotiorum isolates collected from asparagus lettuce field in Jiangsu Province, China, 132 isolates (76.74%) exhibited low-level resistance to boscalid (BosLR), with a discriminatory dose of 5 μg mL−1. In comparison to the boscalid-sensitive (BosS) isolates, most BosLR isolates demonstrated a slightly superior biological fitness, as evidenced by data on mycelial growth, sclerotium production and pathogenicity. Moreover, most BosLR isolates showed comparable levels of oxalic acid (OA) accumulation, increased exopolysaccharide (EPS) content and reduced membrane permeability when compared to the BosS isolates. Nevertheless, their responses to distinct stress factors diverged significantly. Furthermore, the effectiveness of boscalid in controlling BosLR isolates on radish was diminished compared to its efficacy on BosS isolates. Genetic mutations were identified in the SDH genes of BosLR isolates, revealing the existence of three resistant genotypes: I (A11V at SDHB, SDHBA11V), II (Q38R at SDHC, SDHCQ38R) and III (SDHBA11V+SDHCQ38R). Importantly, no cross-resistance was observed between boscalid and other fungicides such as thifluzamide, pydiflumetofen, fluazinam, or tebuconazole. Our molecular docking analysis indicated that the docking total score (DTS) of the type I resistant isolates (1.3993) was lower than that of the sensitive isolates (1.7499), implying a reduced affinity between SDHB and boscalid as a potential mechanism underlying the boscalid resistance in S. sclerotiorum. These findings contribute to an enhanced comprehension of boscalid’s mode of action and furnish valuable insights into the management of boscalid resistance.

An increasing level of pesticide exposition is being observed as a result of the consumption of large amounts of fruits, vegetables and grain products, which are key components of the vegetarian diet. Fungicides have been classified as endocrine-disrupting compounds, but their mechanisms of action have not yet been clarified. The effect of boscalid (B), cyprodinil (C) and iprodione (I) combined with Tamoxifen (T) and 17β-estradiol (E2) on cell viability, cell proliferation, reporter gene expression, ROS content, the cell membrane's function, cell morphology and antioxidant enzymes gene expression in MCF-7 and T47D-KBluc cell lines were investigated. The cell lines were chosen due to their response to 17β -estradiol. The selected fungicides are commonly used in Poland to protect crops against fungi. Our results revealed that the studied fungicides caused significant increases in cell viability and proliferation, and estrogenic activity was present in all studied compounds depending on their concentrations. Oxidative stress activated uncontrolled cancer cell proliferation by inducing ROS production and by inhibiting antioxidant defense. Our findings verify that the studied fungicides could possibly exhibit endocrine-disrupting properties and exposure should be avoided. [ABSTRACT FROM AUTHOR]

Fungal plant pathogens have posed a significant threat to crop production. However, the large-scale application of pesticides is associated with possible risks for human health and the environment. Boscalid is a widely used fungicide, consistently implemented for the management of significant plant pathogens. Conventionally, the detection and determination of boscalid residues is based on chromatographic separations. In the present study, a Bioelectric Recognition Assay (BERA)-based experimental approach combined with MIME technology was used, where changes in the electric properties of the membrane-engineering cells with anti-boscalid antibodies were recorded in response to the presence of boscalid at different concentrations based on the maximum residue level (MRL) for lettuce. The membrane-engineering Vero cells with 0.5 μg/mL of antibody in their surface were selected as the best cell line in combination with the lowest antibody concentration. Furthermore, the biosensor was tested against another fungicide in order to prove its selectivity. Finally, the BERA cell-based biosensor was able to detect the boscalid residue, below and above the MRL, in spiked lettuce leaf extracts in an entirely distinct and reproducible manner. This study indicates that the BERA-based biosensor, after further development and optimization, could be used for the routine, high-throughput detection of boscalid residue in lettuce, and not only that.

Black spot disease or Alternaria black spot (ABS) of pecan (Carya illinoinensis) in South Africa is caused by Alternaria alternata. This fungal pathogen impedes the development of pecan trees and leads to low yield in pecan nut production. The present study investigated the in vitro effect of six fungicides against the mycelial growth of A. alternata isolates from ABS symptoms. Fungicides tested include Tilt (propiconazole), Ortiva (azoxystrobin), AgTin (fentin hydroxide), and Bellis (boscalid + pyraclostrobin). All fungicides were applied in 3 concentrations (0.2, 1, and 5 μg mL−1). Tilt and Bumper 250 EC containing propiconazole active ingredient (demethylation Inhibitors) were the most effective and inhibited all mycelial growth from up to 6 days post-incubation. The other active ingredients (succinate dehydrogenase inhibitors, organotin compounds, and quinone outside inhibitors) showed 75–85% mycelial growth inhibition. The effective concentration to inhibit mycelial growth by 50% (EC50) was estimated for each isolate and fungicide. The overall mean EC50 values for each fungicide on the six isolates were 1.90 μg mL−1 (Tilt), 1.86 μg mL−1 (Ortiva), 1.53 μg mL−1 (AgTin), and 1.57 μg mL−1 for (Bellis). This initial screening suggested that propiconazole fungicide was the most effective for future field trials test and how these fungicides could be used in controlling ABS disease. [ABSTRACT FROM AUTHOR]

The binding of pesticide residues and fruit components may have a profound impact on pesticide dissipation and the functional characteristics of the corresponding components. Therefore, the interaction between boscalid and tannic acid (TA, a representative phenolic in fruit) was systematically investigated using spectroscopic, thermodynamic, and computational chemistry methods. A separable system was designed to obtain the boscalid–TA complex. Fourier transform infrared and 1H‐NMR spectroscopies indicated the formation of hydrogen bonds in the complex. Isothermal titration calorimetry showed that the complex bound spontaneously through hydrophobic interactions (ΔG < 0, ΔH > 0, ΔS > 0), with a binding constant of 6.0 × 105 M−1 at 298 K. The molecular docking results further confirmed the formation of hydrogen bonds and hydrophobic interactions in the complex at the molecular level, with a binding energy of −8.43 kcal mol−1. In addition, the binding of boscalid to TA significantly decreased the antioxidant activity of TA. The binding of boscalid residue to TA was characterized at the molecular level, which significantly reduced the in vitro antioxidant properties of TA. Practical Application: This study provides a reference for the molecular mechanisms of the interaction between pesticide residues and food matrices, as well as a basis for regulating bound‐state pesticide residues in food. [ABSTRACT FROM AUTHOR]

There is a growing risk of pollinators being exposed to multiple fungicides due to the widespread use of fungicides for plant protection. A safety assessment of honeybees exposed to multiple commonly used fungicides is urgently required. Therefore, the acute oral toxicity of the ternary mixed fungicide of ABP (azoxystrobin: boscalid: pyraclostrobin = 1:1:1, m/m/m) was tested on honeybees (Apis cerana cerana), and its sublethal effect on foragers' guts was evaluated. The results showed that the acute oral median lethal concentration (LD50) of ABP for foragers was 12.6 μg a.i./bee. ABP caused disorder of the morphological structure of midgut tissue and affected the intestinal metabolism; the composition and structure of the intestinal microbial community was perturbed, which altered its function. Moreover, the transcripts of genes involved in detoxification and immunity were strongly upregulated with ABP treatment. The study implies that exposure to a fungicide mixture of ABP can cause a series of negative effects on the health of foragers. This work provides a comprehensive understanding of the comprehensive effects of common fungicides on non-target pollinators in the context of ecological risk assessment and the future use of fungicides in agriculture. [ABSTRACT FROM AUTHOR]

Insect pollinators provide important crop pollination services but are declining in response to lack of diverse flower resources and exposure to pesticides. Despite increasing evidence that the benefits of insect pollination for crop production depend on other ecosystem services and crop management practices, investigations have mostly been limited to how pollination benefits are affected by insect pest control and soil fertility levels. Here we used a factorial cage experiment in the field to test how pollination by bumble bees, manual weed removal and fungicide application interactively shape faba bean (Vicia faba) yield components, and how weed removal and fungicide application affect bumble bee foraging behaviour. We found that insect pollination and weed removal increased faba bean yield components mostly additively, with insect pollination being the most important factor to maximise yield. The fungicide treatment did not affect crop yield, probably due to the low fungal pathogen incidence in the experiment, but instead affected bumble bee visitation behaviour. Bumble bees visited flowers of fungicide-sprayed plants more often than fungicide-free plants. This has potential consequences on bee health that should be further assessed. Guidelines on pesticide use should be improved by weighing benefits to agricultural productivity against risks for pollinators according to integrated pest and pollinator management principles. Our results emphasise that insect pollination can be an important factor for crop yield. The additive benefits of insect pollination and weed removal to crop yield indicates that they are crop production factors which can be managed for independently. • Insect pollination and weed removal increased faba bean yield additively. • Insect pollination enhanced yield more than weed removal. • Fungicide use did not affect yield components. • Bumble bees visited fungicide-sprayed plants more often than fungicide-free plants. [ABSTRACT FROM AUTHOR]

An increasing level of pesticide exposition is being observed as a result of the consumption of large amounts of fruits, vegetables and grain products, which are key components of the vegetarian diet. Fungicides have been classified as endocrine-disrupting compounds, but their mechanisms of action have not yet been clarified. The effect of boscalid (B), cyprodinil (C) and iprodione (I) combined with Tamoxifen (T) and 17β-estradiol (E2) on cell viability, cell proliferation, reporter gene expression, ROS content, the cell membrane’s function, cell morphology and antioxidant enzymes gene expression in MCF-7 and T47D-KBluc cell lines were investigated. The cell lines were chosen due to their response to 17β -estradiol. The selected fungicides are commonly used in Poland to protect crops against fungi. Our results revealed that the studied fungicides caused significant increases in cell viability and proliferation, and estrogenic activity was present in all studied compounds depending on their concentrations. Oxidative stress activated uncontrolled cancer cell proliferation by inducing ROS production and by inhibiting antioxidant defense. Our findings verify that the studied fungicides could possibly exhibit endocrine-disrupting properties and exposure should be avoided.

Abstract Diaion® HP-20 resin passive samplers deployed in water and sediment samples collected from Lake Ziway were analyzed for 30 organochlorine, organophosphorus, carboxamide, and pyrethroid pesticide residues. The samples were collected from purposely selected sampling stations in five sites on Lake Ziway. Levels of selected pesticides were determined by GC–MS/MS in all samples. p,p′DDE and boscalid residues were the only detected pesticides in sediment samples. Similarly, only metalaxyl and boscalid residues were recovered from HP-20 resins. The concentration of p,p′DDE and boscalid in sediment ranged from 0.66–7.23 and 0.1–15.26 ng g−1 dry weight respectively. The presence of p,p′DDE but no other metabolites of DDT in all sediment samples indicated that DDT residues in Ziway Lake were aged and probably originated from the weathered agricultural soils of the surrounding region. The highest level of boscalid was recorded at Site 2 (near the floriculture enterprises) both in sediment and in HP-20 resins with a mean concentration of 11.8 ng g−1 dw and 39.6 ng g−1 disk respectively. However, the concertation of metalaxyl was the highest in the HP-20 resins deployed at Site1 and Site 4 (near the intensive small-scale vegetable farm) with a mean concentration of 54.7 ng g−1 disk and 54.3 ng g−1 disk respectively. Generally, most sampling sites of p,p′DDE were found to have a moderate ecological risk based on levels specified in the sediment quality standards. Moreover, the relatively high boscalid and metalaxyl levels in HP-20 deployed in Lake Ziway would be the result of recent intensive pesticide use by floriculture enterprises and small-scale vegetable farmers in the region. A spatial variation on the accumulation of detected pesticides among the sampling sites depends on the anthropogenic activities, around the lake from the point and non-point sources. Although most of the analyzed pesticides were below the detectable limit, further studies and continued monitoring of currently used pesticide residues in the Lake are highly recommended.

Alternaria late blight (ALB), caused mainly by the fungal pathogen Alternaria alternata, is an important pistachio disease that causes severe tree defoliation and fruit shell staining. Its control relies on multiple fungicide sprays, including carboxamide fungicides. In 2015, we surveyed 35 orchards representing nine pistachio producing counties of California to determine the current situation of Alternaria resistance to four widely used carboxamide fungicide active ingredients. This survey showed that isolates collected in the northern (Tehama, Glenn and Colusa counties) and southern (Tulare, Kings and Kern counties) Central Valley presented higher frequencies of carboxamide resistance than isolates collected from orchards in the central region (Fresno, Madera and Merced counties). The number of carboxamide usages in a year is the main factor determining elevated resistance. By extracting the A. alternata DNA and sequencing the carboxamide target genes, we evaluated the prevalence of specific molecular alterations (mutations) associated with carboxamide fungicide resistance. Finally, we identified cross-resistance patterns among different carboxamide fungicides, leading to recommendations about combinations to avoid.

Bioactivities of eight fungicides (boscalid, difenoconazole, propiconazole, flusilazole, carbendazim, prochloraz, dimethachlon, mancozeb) to the pathogen of a tobacco leaf spot, Didymella segeticola, were determined using bioassay method at the mycelial growth stage. In vivo protective and curative effects of these fungicides against D. segeticolla on detached tabbaco leaves were also analyzed. The results showed that eight fungicides exhibited different inhibitory activities against mycelial growth of the pathogen, and also showed some protective and curative efficacies against the leaf spot. The most effecient one against mycelial growth of the pathogen was boscalid, with an EC50 value of (0.047 0 ± 0.012 0) mg/L; followed by difenoconazole [(0.079 0 ± 0.005 0) mg/L], prochloraz [(0.29 ± 0.08) mg/L], propiconazole [(0.69 ± 0.12) mg/L], dimethachlon [(1.08 ± 0.33) mg/L], carbendazim [(1.22 ± 0.29) mg/L], flusilazole [(1.38 ± 0.07) mg/L]; and most least effecient one was mancozeb with an EC50 value of (22.80 ± 10.51) mg/L. Flusilazole, difenoconazole, propiconazole, boscalid and dimethachlon all had better protective activity for the control of this disease with >82% efficacy at 25 mg/L dosage treatment than 100 mg/L mancozeb showed 70.51% efficacy. Both boscalid and flusilazole showed better curative activities, with efficacies of >80% at 25 mg/L dosage treatment, followed by prochloraz, difenoconazole, carbendazim and dimethachlon; mancozeb showed relatively poor activity with 63.31% efficacy at 100 mg/L dosage treatment. The results provide scientific basis and reference for the screening of fungicides to control tobacco leaf spot. [ABSTRACT FROM AUTHOR]

The excessive use of fungicides against Venturia inaequalis, the causal agent of apple scab, has led to the emergence of resistant populations to multiple fungicides over the years. In Greece, there is no available information on fungicide resistance, despite the fact that control failures have been reported on certain areas. An amount of 418 single-spore isolates were collected from three major apple production areas and tested for their sensitivity to eight commonly used fungicides from unrelated chemical groups. The isolates were tested on malt extract agar media enriched with the discriminatory dose of each fungicide using the point inoculation method. To define the discriminatory dose for assessing the levels of resistance, EC50 values on both spore germination and mycelial growth assays were previously determined. Isolates exhibiting high resistance to trifloxystrobin (92% in total) and difenoconazole (3%); and moderate resistance to cyprodinil (75%), dodine (28%), difenoconazole (36%), boscalid (5%), and fludioxonil (7%) were found for the first time in Greece. A small percentage of the isolates were also found less sensitive to captan (8%) and dithianon (6%). Two isolates showed various levels of resistance to all eight fungicides. Despite the occurrence of strains with multiple resistances to many fungicides, we concluded that this practical resistance in the field arose mainly due to the poor control of apple scab with trifloxystrobin and difenoconazole. [ABSTRACT FROM AUTHOR]

In order to find amide compounds with desired antifungal activity, 16 nicotinamide derivatives containing diphenylamine moieties were prepared by condensation of 2-chloronicotinic acid with substituted N1-phenylbenzene-1,2-diamines based on the structure of fungicide boscalid. The structures of the synthesized compounds were characterized by 1H NMR, 13C NMR, ESI-MS, and elemental analysis. Among the compounds screened, compound 3a had high inhibitory effects against Rhizoctonia solani in vitro and in vivo, which slightly exceeded boscalid. The study of the structure-activity relationship provides important information for further structural optimization. Molecular docking offered a reasonable explanation to guarantee its fungicidal activity against R. solani. These results could provide a benchmark for understanding the antifungal activity against the phytopathogenic fungus R. solani and prompt us to develop more potent fungicides. Sixteen nicotinamide derivatives containing diphenylamine moieties were prepared based on the structure of fungicide boscalid. Thereinto, compound 3a showed high antifungal activity against Rhizoctonia solani. Structure-activity relationship study provided important information for further structural optimization. Molecular docking offered a reasonable explanation to guarantee its fungicidal activity. [ABSTRACT FROM AUTHOR]

Plant protection products to be placed on the market in the European Union need to meet rigorous safety criteria including the testing of lumbricid earthworms, the functionally most important soil organism group in Central European agricultural ecosystems. To address uncertainties and investigate the potential long‐term in‐crop effects of the fungicide Cantus® containing 50% boscalid as an active substance, a series of standardized earthworm field studies with an overall duration of 5 years per study program was carried out in four German agricultural fields under realistic crop rotation conditions. A two‐step approach was chosen to analyze the potential overall long‐term effects on earthworms in agricultural fields: (i) an assessment of the earthworm abundance development in the course of the four study programs in relation to the determined actual content of boscalid in soil and (ii) an effect size meta‐analysis of earthworm abundance 1 year after treatment for each consecutive year and study program. Measured boscalid concentrations in the soil after multiple applications were well above the maximum boscalid residues observed in agricultural soils across Central Europe. There were isolated statistically significant reductions of earthworm abundance for some species and groups at some time points during the studies, but no consistent relationship to the Cantus® treatments was observed. These results were supported by the meta‐analysis, indicating no adverse effects on earthworm populations. Therefore, fluctuations of abundance reflect the natural variation of the populations rather than a concentration‐related response. Based on this comprehensive analysis, we conclude that there is no application rate‐related effect of the 5‐year use of Cantus® on the development of the earthworm communities. The four study programs, paired with a comprehensive evaluation, directly address the concerns about the potential long‐term effects of boscalid on earthworms in the field and suggest that multiyear applications do not adversely affect earthworm populations. Integr Environ Assess Manag 2022;18:1399–1413. © 2021 ECT Oekotoxikologie GmbH and BASF SE. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: A series of standardized earthworm field studies with the fungicide Cantus® containing 50% boscalid as active substance and with an overall duration of 5 years per study program was carried out in four German agricultural fields under realistic crop rotation conditions.The development of earthworm abundance in the course of the four study programs in relation to the determined actual content of boscalid in soil was assessed and an effect size meta‐analysis of earthworm abundance one year after treatment for each consecutive year and study program was performed.Measured boscalid concentrations in soil after multiple applications were well above the maximum boscalid residues observed in agricultural soils across Central Europe.The four study programs, paired with a comprehensive evaluation, directly address the concerns about potential long‐term effects of boscalid on earthworms in the field and suggest that multiyear applications do not adversely affect earthworm populations. [ABSTRACT FROM AUTHOR]

Fungicides containing active ingredients of boscalid and pyraclostrobin have been widely applied in watermelon disease control. To provide data for avoiding health hazards caused by fungicides, we investigated its terminal residues and evaluated the dietary risk. In this work, watermelon samples were collected from field sites in six provinces and analyzed with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The average recoveries of boscalid and pyraclostrobin in the watermelon matrix were 97–108% and 93–103%, respectively, with the relative standard deviations (RSDs) ≤ 9.1%. The limits of quantifications (LOQs) were 0.01 and 0.005 mg/kg for boscalid and pyraclostrobin. Twenty-one days after applying the test pesticide with 270 g a.i./ha, the terminal residues of boscalid and pyraclostrobin were all below 0.05 mg/kg and below the maximum residue limits (MRLs) recommended by European Food Safety Authority (EFSA). According to the national estimated daily intake (NEDI), the risk quotients (RQs) of boscalid and pyraclostrobin were 48.4% and 62.6%, respectively. That indicated the pesticide evaluated in watermelon exhibited a low dietary risk to consumers. All data provide a reference for the MRL establishment of boscalid in watermelon for China. [ABSTRACT FROM AUTHOR]

Black spot disease or Alternaria black spot (ABS) of pecan (Carya illinoinensis) in South Africa is caused by Alternaria alternata. This fungal pathogen impedes the development of pecan trees and leads to low yield in pecan nut production. The present study investigated the in vitro effect of six fungicides against the mycelial growth of A. alternata isolates from ABS symptoms. Fungicides tested include Tilt (propiconazole), Ortiva (azoxystrobin), AgTin (fentin hydroxide), and Bellis (boscalid + pyraclostrobin). All fungicides were applied in 3 concentrations (0.2, 1, and 5 μg mL−1). Tilt and Bumper 250 EC containing propiconazole active ingredient (demethylation Inhibitors) were the most effective and inhibited all mycelial growth from up to 6 days post-incubation. The other active ingredients (succinate dehydrogenase inhibitors, organotin compounds, and quinone outside inhibitors) showed 75–85% mycelial growth inhibition. The effective concentration to inhibit mycelial growth by 50% (EC50) was estimated for each isolate and fungicide. The overall mean EC50 values for each fungicide on the six isolates were 1.90 μg mL−1 (Tilt), 1.86 μg mL−1 (Ortiva), 1.53 μg mL−1 (AgTin), and 1.57 μg mL−1 for (Bellis). This initial screening suggested that propiconazole fungicide was the most effective for future field trials test and how these fungicides could be used in controlling ABS disease.

Dollar spot, a highly destructive turfgrasses disease worldwide, is caused by multiple species within the genus Clarireedia. Previous research indicated varying sensitivity to boscalid among Clarireedia populations not historically exposed to succinate dehydrogenase inhibitors (SDHIs). This study confirms that the differential sensitivity pattern is inherent among different Clarireedia spp., utilizing a combination of phylogenetic analyses, in vitro cross-resistance assays, and genetic transformation of target genes with different mutations. Furthermore, greenhouse inoculation experiments revealed that the differential boscalid sensitivity did not lead to pathogenicity issues or fitness penalties, thereby not resulting in control failure by boscalid. This research underscores the importance of continuous monitoring of fungicide sensitivity trends and highlights the complexity of chemical control of dollar spot due to the inherent variability in fungicide sensitivity among different Clarireedia spp. [Display omitted] • Varied sensitivity to boscalid among different Clarireedia species • Genetic transformation confirmed the varied sensitivity due to mutations on sdh genes • Similar topology was observed in the phylogenetic trees based on ITS and sdh genes • The varied sensitivity did not cause control failure by boscalid [ABSTRACT FROM AUTHOR]

The extensive application of pesticides and antibiotics in agricultural production makes it possible for them to coexist in farmland, and the interaction of the two pollutants can lead to changes in environmental behavior and toxicity, creating uncertainty risks to soil and soil organisms. In this study, we explored the environmental behavior and the effects of earthworms under co-exposure to amoxicillin and boscalid and further explored the accumulation and toxic effects on earthworms. The results showed that amoxicillin increased the adsorption of boscalid in soil and inhibited its degradation. In addition, we noticed that the co-exposure of amoxicillin and boscalid caused intestinal barrier damage, which increased the bioaccumulation of earthworms for boscalid and led to more severe oxidative stress and metabolic disorders in earthworms. In summary, our findings indicate that amoxicillin can increase the ecological risk of boscalid in the environment and imply that the encounter between antibiotics and pesticides in the environment can amplify the toxic effects of pesticides, which provides new insights into the ecological risks of antibiotics. [Display omitted] • AMO results in increased adsorption of BOS in soil and half-life prolongation. • Co-exposure to AMO and BOS aggravated the destruction of the intestinal barrier. • The destruction of the intestinal barrier led to an increase in bioaccumulation. • Co-exposure to AMO and BOS aggravated oxidative stress and metabolic disorders. • The results revealed the combined risk of pesticides and antibiotics. [ABSTRACT FROM AUTHOR]

• Introduce the diphenyl ether fragments into the structure of boscalid, design and synthesize 24 nicotinamide derivatives. • Several highly promising antifungal compounds have been discovered in the synthesized title compounds. • Theoretical calculation reveals the structural characteristics of biphenyl, diphenylamine and diphenyl ether fragments, and offers guidance for further optimization and design of compounds with higher antifungal activity. • Biological evaluation indicates that the title compound 7g is expected to become a candidate for SDHIs with high efficiency and low toxicity. To obtain nicotinamide fungicides with higher inhibitory activity against Rhizoctonia solani , 24 nicotinamide derivatives were designed and synthesized by introducing the diphenyl ether fragments into the structure of boscalid. Biological assays revealed that the obtained compounds exhibited varying degrees of antifungal activity. Among them, compound 2-chloro- N -(2-(2,4-dichlorophenoxy)phenyl)nicotinamide (7g) exhibited prominent biological activity against R. solani (EC 50 = 0.034 mg/L), surpassing the inhibitory effect of boscalid. Experimentally, compound 7g was a promising fungicide with low toxicity that targeted succinate dehydrogenase, as confirmed by the tests of cytotoxicity, inhibition of enzyme activity, mitochondrial membrane potential, and mycelial respiration. This study highlighted the potential of nicotinamide derivatives containing diphenyl ether fragments designed based on theoretical calculations as succinate dehydrogenase inhibitor (SDHI) fungicides. [Display omitted] [ABSTRACT FROM AUTHOR]

Effective and safe smoke generators were urgently needed to control gray mold of Chinese chives. In this study, the feasibility of processing nine commonly used fungicides into smoke generator was evaluated from five aspects: inhibition activity of active compounds, toxicity of smoke, smoke formation rate, safety, and field control. The inhibition activity of active compounds results showed that EC50 values of fluazinam, fludioxonil, and pyrisoxazole against mycelial growth were 0.13, 0.05, and 0.12 mg/L; EC50 values of pyrazolamide, fluopyram, and boscalid against conidial germination were 0.84, 0.68, and 1.16 mg/L. In a 0.108 m³ containment device, the toxicity of the smoke of fungicides at the same dose of 0.01 g was tested, the results showed that with the same dose of 0.01 g, the mycelial growth were completely inhibited by smoked fludioxonil, while the conidial germination was completely inhibited by smoked pyrazolamide, fluopyram, and boscalid, the inhibition rates of registered procymidone smoke generator against mycelial growth and conidial germination were 54.39% and 43.27%. The smoking rate of fludioxonil, boscalid, and fluopyram were 85.93%, 91.35%, and 82.86%, which conform to the criterion of active ingredient for fabricating smoke generators. Seven days after fungicide smokes treatment, there was no significant difference in plant height and stem diameter of Chinese chives compared with the untreated control. The results of the field trials in 2019 and 2020 showed that the curative efficacy of active ingredient of 120 g/hm² fludioxonil smoke generator to gray mold were 72.31% and 79.78%, and the curative efficacy of active ingredient of 375 g/hm² boscalid smoke generator to gray mold were 81.17% and 83.81%. Their curative efficacy was all higher than the procymidone smoke generator at the highest registered dose (the active ingredient of 450 g/hm² ), in the treatment of grey mold of Chinese chives (59.86% and 63.71%). At the above doses, the preventative efficacies of three smoke generators to control gray mold were all above 90%. The dissipation dynamics of curves of the fludioxonil and boscalid were both in line with the first-order kinetic equation. The both half-lives of fludioxonil and boscalid in Chinese chives plant were 3-4 d. It is recommended that fludioxonil and boscalid are processed into smoke generators and registered for the prevention and control of gray mold of Chinese chives. [ABSTRACT FROM AUTHOR]

The sensitivity of Monilinia fructicola to boscalid was determined by the mycelial growth rate method. Meanwhile, the study investigated the biological characteristics of isolates with different sensitivities, the correlation between the amino acid mutations of SDHB protein with resistance to boscalid, and the cross-resistance of M. fructicola between boscalid and other 3 tested succinate dehydrogenase inhibitors (SDHIs), Y12196, penflufen and fluopyram. The results showed that boscalid had a good inhibitory activity and therapeutic effect against M. fructicola. However, M. fructicola has developed a certain degree of resistance, and the resistant isolates have comparable fitness with the sensitive ones. The sequence analysis of SDHB gene showed that the amino acid point mutations of M. fructicola SDHB subunits were not significantly correlated with the resistance to boscalid. The crossresistance studies indicated that there was cross-resistance between boscalid and the other three SDHIs, Y12196, penflufen, and fluopyram. In order to retard the occurrence and exacerbation of resistance, the rational mixes or rotations of boscalid with other kinds of fungicides rather than SDHIs are recommended during the prevention and control of cherry brown rot disease. [ABSTRACT FROM AUTHOR]

The purpose of this research was to reduce the amount of noble metal palladium catalyst and improve the catalytic performance in the Suzuki–Miyaura cross-coupling reaction, which is the key step in the synthesis of Boscalid. Taking o-bromonitrobenzene and p-chlorophenylboronic acid as raw materials, three kinds of Pd-PEPPSI-IPr catalysts were synthesized and employed in the Suzuki reaction, and then the biaryl product was subjected to reduction and condensation reaction to give Boscalid. Under the optimal reaction conditions, the result showed that the catalytic system exhibits highest catalytic efficiency under aerobic conditions, giving the 2-(4-chlorophenyl)nitrobenzene in over 99 % yield. Moreover, the Pd-PEPPSI-IPrDtBu-An catalyst was minimized to 0.01 mol%. The synthesis process was mild, the post-treatment was simple, and the production cost was reduced, which makes it suitable for industrial production.

A total of 112 isolates of Stagonosporppsis citrulli were collected from 5 locations in Zhejiang Province. The resistance to thiophanate-methyl（Ben） and boscalid（Bos） was detected by the method of differentiated doses. The results showed that the respective resistance frequencies were 100%and 28.6% to Ben and Bos, respectively. The high-level resistance（Ben HR） of thiophanate-methyl reached 100%, and the low-level resistance（Bos LR） and high-level resistance（Bos HR） of boscalid were18.8% and 9.8%, respectively. Further studies on the molecular mechanism of resistance showed that the Ben HR of S. citrulli was caused by the E198 A point mutation in β-tubulin, which was the mutation of198 th amino acid of from Glu（E） to Ala（A）. The mechanism of Bos HR was the point mutation in 277 th amino acid of Sdh B from His（H） to Tyr（Y）, but the mechanism of low-level resistance（Bos LR） still needs to be studied. To sum up, the resistance of S. citrulli population to benzimidazole fungicides in Zhejiang Province was very serious. Most isolates were sensitive to boscalid, but the high-level resistance has occurred in some regions. Therefore, attention should be paid to the scientific use of SDHIs and resistance monitoring should be strengthened. [ABSTRACT FROM AUTHOR]

In order to clarify the potential application of difenoconazole and boscalid in the control of gummy stem blight (GSB), fungicide coformulations that have a synergistic effect on GSB were screened, and preliminary studies were conducted on their synergistic mechanism. In this study, the mycelium growth rate method was used to determine the sensitivity of 101 strains of GSB to difenoconazole and boscalid. Indoor virulence and field efficacy tests were carried out on GSB to screen out fungicides with better inhibition effect. The results of sensitivity test showed that the maximum EC50 value of difenoconazole was 0.171 μg/ml, with a minimum of 0.0135 μg/ml and a mean EC50 value of 0.0569 ± 0.00289 μg/ml. Meanwhile, the maximum EC50 value of boscalid was 0.180 μg/ml with a minimum of 0.0330 μg/mL and a mean EC50 value of 0.0850 ± 0.0370 μg/mL and the frequency distribution of the EC50 values are single peak curves, so that the average of the EC50 values was used as the baseline sensitivity of GSB to difenoconazole and boscalid. The screening results of the fungicide co-formulations indicated that the 1:9 and 2:8 ratios of difenoconazole and boscalid were both effective against GSB. When the mass ratios of difenoconazole and boscalid were 1:9 and 2:8, the synergistic coefficient (SR) was 1.8188 and 1.5011, respectively. The control effect of the fungicide coformulation reached more than 83% for both the medium and high doses set, which was higher than the control effect of each single agent. The results of the synergistic mechanism showed that the fungicide co-formulation had an inhibitory effect on the mycelial growth, conidial production, spore germination rate, etc. At the same time, the fungicide co-formulation had a synergistic effect on enhancing cell membrane permeability and accelerating membrane lipid peroxidation, and had an additive effect on inhibiting ergosterol synthesis. Therefore, the experiment provided theoretical evidence for the control of GSB and the management of fungicide. [ABSTRACT FROM AUTHOR]

Powdery mildew is caused by Podosphaera xanthii, and is one of the most important diseases that attacks Spanish cucurbit crops. Fungicide application is the primary control tool; however, its effectiveness is hampered by the rapid development of resistance to these compounds. In this study, the EC50 values of 26 isolates were determined in response to the succinate dehydrogenase inhibitor (SDHI) fungicides boscalid and fluopyram. From these data, the discriminatory doses were deduced and used for SDHI resistance monitoring during the 2018 and 2019 growing seasons. Of the 298 isolates analysed, 37.9% showed resistance to boscalid and 44% to fluopyram. Although different phenotypes were observed in leaf disc assays, the resistant isolates showed the same phenotype in plant assays. Compared to sensitive isolates, two amino acid changes were found in the SdhC subunit, A86V and G151R, which are associated mostly with resistance patterns to fluopyram and boscalid, respectively. Furthermore, no significant differences were observed in terms of fitness cost between the selected sensitive and resistant isolates analysed here. Lastly, a loop-mediated isothermal amplification (LAMP) assay was developed to detect A86V and G151R mutations using conidia obtained directly from infected material. Our results show that growers could continue to use boscalid and fluopyram, but resistance management practices must be implemented. [ABSTRACT FROM AUTHOR]

The pathogenic fungus causing tobacco brown spot in Guizhou Province was isolated and identified from diseased samples collected during 2014 to 2015, which have never been treated with succinate dehydrogenase inhibitors(SDHIs), and their sensitivity baseline to boscalid was established by mycelial growth rate tests. The results suggested that there were significant differences in colony and conidium morphlogy, and pathogencicity among these isolates. However, all isolates were identified as Alternaria alternata. In addition, the EC50 values of boscalid inhibiting the growth of A. alternata population (n = 102) from tobacco fitted unimodal distribution and varied from 0.186 to 5.818 μg/mL with the mean value of (2.157 ± 1.112) μg/mL, which could be adopted as the baseline sensitivity of A. alternata on tobacco to boscalid and used for monitoring the sensitivity shift in future. Further study indicated that there was some nucleotide polymorphism in codons, such as 209, 277 and 224 in Sdh B of A. alternata. However, no relationship was observed between this nucleotide diversity and the sensitivity to boscalid in A. alternata causing tobacco brown spot. [ABSTRACT FROM AUTHOR]

Coffee Berry Disease(CBD) caused by Colletotrichum kahawae is a destructive fungal disease of coffee in Kenya, leading to a loss of about 75%. This study aimed to assess the In Vitro efficacy of two fungicides:-CRI 1 (Pyraclostrobin 150 g/L + Fluxapyroxad 75 g/L) and CRI 2 (Pyraclostrobin 128 g/Kg + Boscalid 252 g/Kg) against C. kahawae using poisoned food technique on Potato Dextrose Agar. A total of 170 coffee berries with C. kahawae symptoms were purposively collected from both sprayed and unsprayed plots. Ten rates of each of the two fungicides were assessed ranging from 0.01% to 0.1% at an interval of 0.01%. Two commercial standard fungicides Pyraclostrobin 250 g/L at 0.04% and Tebuconazole 200 g/L + Trifloxystrobin 100 g/L at 0.1% were used as positive controls. Fungal inoculum in PDA media devoid of the fungicide acted as the negative control. Data on colony diameter was collected after every 24 hours for 13 days. Analysis of Variance (ANOVA) of the data on colony diameter was done using CoStat software version 6.400. The results revealed that all the rates of CRI 1 and CRI 2 fungicides controlled the colony diameter of C. kahawae compared to the control treatment. CRI 1 fungicide suppressed the growth of C. kahawae even at the lowest concentration of 0.01% with a percentage control of 64.74 %. The highest concentration of 0.1% had a percentage control of 66.15%. CRI 1 is more effective in controlling C. kahawae since it controls the fungus at a rate even lower than Pyraclostrobin 250 g/L which had a percentage control of 66.10 at a recommended rate of 0.04% and Tebuconazole 200 g/L + Trifloxystrobin 100 g/L fungicides which had a percentage control of 65.76 at a recommended rate of 0.1%. CRI 1 also hade a better percentage control as compared to CRI 2. CRI 2 had a percentage control of 54.63% at the highest rate of 0.1% and a percentage control of 35.60% at the lowest rate of 0.01%. Further studies on CRI 1 and CRI 2 fungicides should be carried out for yield assessment in the field. [ABSTRACT FROM AUTHOR]

The genotoxic potential of the plant protection product Signum® and its two active substances (pyraclostrobin and boscalid) was investigated by the comet assay (pH>13). Leukocytes isolated from whole blood were treated with different concentrations (0.1-25 µg/ml) of the fungicide for 2 h and 20 h. The Trypan Blue exclusion test showed higher cell viability (>84%) under all three concentrations and in the two treatment periods. The obtained results revealed that both Signum® and pyraclostrobin induced statistically significant DNA damage. In contrast, boscalid did not cause statistically significant DNA damage after 2 h exposure although it caused DNA damage at higher concentrations after a longer time exposure (20 h). It is deducible that pyraclostrobin and Signum® might be genotoxic. However, within the studied concentration ranges, none of the fungicides was found to be cytotoxic in the two treatment periods.

Fungicides containing active ingredients of boscalid and pyraclostrobin have been widely applied in watermelon disease control. To provide data for avoiding health hazards caused by fungicides, we investigated its terminal residues and evaluated the dietary risk. In this work, watermelon samples were collected from field sites in six provinces and analyzed with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The average recoveries of boscalid and pyraclostrobin in the watermelon matrix were 97–108% and 93–103%, respectively, with the relative standard deviations (RSDs) ≤ 9.1%. The limits of quantifications (LOQs) were 0.01 and 0.005 mg/kg for boscalid and pyraclostrobin. Twenty-one days after applying the test pesticide with 270 g a.i./ha, the terminal residues of boscalid and pyraclostrobin were all below 0.05 mg/kg and below the maximum residue limits (MRLs) recommended by European Food Safety Authority (EFSA). According to the national estimated daily intake (NEDI), the risk quotients (RQs) of boscalid and pyraclostrobin were 48.4% and 62.6%, respectively. That indicated the pesticide evaluated in watermelon exhibited a low dietary risk to consumers. All data provide a reference for the MRL establishment of boscalid in watermelon for China.

Copyright of Yuzuncu Yil Universitesi Journal of Agricultural Sciences (YYU J Agr Sci) is the property of Yuzuncu Yil University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bumble bees, Bombus spp. (Apidae), are important native pollinators; however, populations of some species are declining in North America and agricultural chemicals are a potential cause. Fungicides are generally not highly toxic to bees, but little is known about sublethal or synergistic effects. This study evaluates bumble bee exposure to fungicides by quantifying concentrations of boscalid and pyraclostrobin in nectar and pollen collected by colonies of Bombus huntii Greene, 1860 (Hunt bumble bee) deployed in a commercial cherry Prunus avium L. orchard in the spring of 2016. Seven colonies were placed adjacent to an orchard block that was sprayed with a fungicide mixture of boscalid and pyraclostrobin and a control group of seven colonies was placed next to an unsprayed block of orchard 400 m away from the treated block. Nectar and pollen were collected daily, beginning 1 d before spray application and continuing for a total of 12 d, and analyzed for both fungicides. Fungicide concentrations varied spatially by colony and temporally by day. The highest concentrations in nectar occurred 1 and 3 d after spraying: up to 440 ng/g boscalid and 240 ng/g pyraclostrobin. Six days after application, pollen from cherry flowers contained the highest concentrations of the fungicides: up to 60,500 ng/g boscalid and 32,000 ng/g pyraclostrobin. These data can help to determine field-level fungicide concentrations in nectar and pollen and direct future work on understanding the effects of these compounds, including their interactions with important bumble bee pathogenic and beneficial symbionts. [ABSTRACT FROM AUTHOR]

Succinate dehydrogenase inhibitors (SDHIs) are a class of broadspectrum fungicides used for management of diseases caused by phytopathogenic fungi. In many cases, reduced sensitivity to SDHI fungicides has been correlated with point mutations in the SdhB and SdhC target genes that encode components of the succinate dehydrogenase complex. However, the genetic basis of SDHI fungicide resistance mechanisms has been functionally characterized in very few fungi. Sclerotinia sclerotiorum is a fast-growing and SDHI fungicide-sensitive phytopathogenic fungus that can be conveniently transformed. Given the high amino acid sequence similarity and putative structural similarity of SDHI protein target sites between S. sclerotiorum and other common phytopathogenic ascomycete fungi, we developed an in vitro heterologous expression system that used S. sclerotiorum as a reporter strain. With this system, we were able to demonstrate the function of mutant SdhB or SdhC alleles from several ascomycete fungi in conferring resistance to multiple SDHI fungicides. In total, we successfully validated the function of Sdh alleles that had been previously identified in field isolates of Botrytis cinerea, Blumeriella jaapii, and Clarireedia jacksonii (formerly S. homoeocarpa) in conferring resistance to boscalid, fluopyram, or fluxapyroxad and used site-directed mutagenesis to construct and phenotype a mutant allele that is not yet known to exist in Monilinia fructicola populations. We also examined the functions of these alleles in conferring cross-resistance to more recently introduced SDHIs including inpyrfluxam, pydiflumetofen, and pyraziflumid. The approach developed in this study can be widely applied to interrogate SDHI fungicide resistance mechanisms in other phytopathogenic ascomycetes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Boscalid is often used to extend the storage time of postharvest cherry tomato. Pesticide residue has become an issue of food safety. This study sought to investigate the spatial distribution of boscalid residue in cherry tomato fruits and to determine the effect of 24‐epibrassinolide (EBR) in promoting boscalid degradation. RESULTS: Boscalid could quickly penetrate into cherry tomatoes, but mainly remained in the peel. The migration of boscalid from the peel into the core was a time‐consuming and complex process during storage. After 72 h, boscalid residues in the pulp and the core began to accumulate gradually. The exogenous application of EBR activated peroxidase, glutathione reductase and glutathione S‐transferase, and effectively promoted the degradation of boscalid by a maximum decrease of 44.8% in peel, 54.0% in pulp and 71.2% in core. CONCLUSION: As one of the common pesticides, boscalid had a strong ability to enter the cherry tomato and thus become a potential risk for public consumption. Therefore, rational use of pesticides is recommended. The results of this study indicate that the possible risk of boscalid residue could be alleviated by EBR pretreatment through activating detoxification enzymes. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The purpose of this research was to reduce the amount of noble metal palladium catalyst and improve the catalytic performance in the Suzuki-Miyaura cross-coupling reaction, which is the key step in the synthesis of Boscalid. Taking o-bromonitrobenzene and p-chlorophenylboronic acid as raw materials, three kinds of Pd-PEPPSI-IPr catalysts were synthesized and employed in the Suzuki reaction, and then the biaryl product was subjected to reduction and condensation reaction to give Boscalid. Under the optimal reaction conditions, the result showed that the catalytic system exhibits highest catalytic efficiency under aerobic conditions, giving the 2-(4-chlorophenyl)nitrobenzene in over 99 % yield. Moreover, the Pd-PEPPSI-IPrDtBu-An catalyst was minimized to 0.01 mol%. The synthesis process was mild, the post-treatment was simple, and the production cost was reduced, which makes it suitable for industrial production. [ABSTRACT FROM AUTHOR]

Copyright of Erwerbs-Obstbau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant BASF SE submitted a request to the competent national authority in Greece to modify the existing maximum residue level (MRL) for the active substance boscalid in granate apples/pomegranates. The data submitted in support of the request were found to be sufficient to derive an MRL proposal for pomegranates. Adequate analytical methods for enforcement are available to control the residues of boscalid in the commodity under consideration at the validated limit of quantification (LOQ) of 0.01 mg/kg. Based on the risk assessment results, EFSA concluded that the long‐term intake of residues resulting from the use of boscalid according to the reported agricultural practice is unlikely to present a risk to consumer health. The reliable end points, appropriate for use in regulatory risk assessment are presented.

Alternaria late blight (ALB), caused mainly by the fungal pathogen Alternaria alternata, is an important pistachio disease that causes severe tree defoliation and fruit shell staining. Its control relies on multiple fungicide sprays, including carboxamide fungicides. In 2015, we surveyed 35 orchards representing nine pistachio producing counties of California to determine the current situation of Alternaria resistance to four widely used carboxamide fungicide active ingredients. This survey showed that isolates collected in the northern (Tehama, Glenn and Colusa counties) and southern (Tulare, Kings and Kern counties) Central Valley presented higher frequencies of carboxamide resistance than isolates collected from orchards in the central region (Fresno, Madera and Merced counties). The number of carboxamide usages in a year is the main factor determining elevated resistance. By extracting the A. alternata DNA and sequencing the carboxamide target genes, we evaluated the prevalence of specific molecular alterations (mutations) associated with carboxamide fungicide resistance. Finally, we identified cross-resistance patterns among different carboxamide fungicides, leading to recommendations about combinations to avoid.

The baseline sensitivity of 55 isolates of Sclerotinia sclerotiorum, collected from oilseed rape in 6 regions of the Czech Republic, to selected fungicides was determined during the period 2013-2015. One single-component fungicide - Horizon (tebuconazole), and four multicomponent fungicides - Pictor (boscalid, dimoxystrobin), Efilor (boscalid, metconazole), Prosaro 250 EC (prothioconazole, tebuconazole), and Propulse (fluopyram, prothioconazole), were chosen as these are commonly used locally. The effect of each fungicide on the in vitro pathogen radial mycelial growth and EC50 values for the respective fungicides were determined. The following MIC values were estimated; for the fungicides Horizon 250 EW, Efilor, and Propulse the mean MIC values ranged between 0.125 and 0.250 µl/ml, for Prosaro 250 EC ranged between 0.0625 and 0.125 µl/ml, and for Pictor ranged from 0.00781 to 0.01562 µl/ml. No strains of S. sclerotiorum resistant to the tested fungicides were detected and the growth of all isolates was fully inhibited at concentrations corresponding to their registered dose rates. The highest fungicidal efficacy on the collected S. sclerotiorum isolates was recorded for Pictor, followed by Prosaro 250 with an EC50 value 0.05856 µl/ml and then the remaining fungicides Propulse, Efilor, and Horizon 250 EW (EC50 values 0.07277, 0.07221, and 0.08519 µl/ml, respectively).

Corynespora leaf spot caused by Corynespora cassiicola has become an important disease affecting cucumber. To provide the basis of biological research for exploring different resistance mechanisms of C. cassiicola to boscalid, the biological characteristics and environmental fitness of C. cassiicola with different types of resistance to boscalid were determined in this study. A total of 24 strains of C. cassiicola collected from different regions with different resistant types to boscalid were randomly selected. Seven types of resistant mutants cross-resistance to several different succinate dehydrogenase inhibitors (SDHIs) were analyzed and whether the mutants could inherite stably after cultivated nine generations on PDA plates without any fungicides selection pressure were determined. Meanwhile, the biological characteristics of resistant mutants under different carbon and nitrogen sources, temperature and other conditions were also determined to evaluate the fitness of resistant mutants under different environmental conditions. The results indicated that only SdhB-H278Y and SdhB-H278R mutants showed negative cross-resistance between boscalid and fluopyram, while drug resistance in all strains of the different mutation types could be inherited stably. Pathogenicity of different mutation types strains were discrepant, and the SdhD-D95E mutants had the strongest pathogenicity. The most favorable carbon source for the growth of all resistant mutants was maltose, and no discrepancy was showed in the effects of different nitrogen sources. The most optimal growth temperature range of each mutant strain was 25-30 ℃, while SdhD-D95E mutants grew faster than other mutants at temperatures greater than 30 ℃. In the study of heat resistance, the resistant mutants were not able to survive after treated at 65 ℃ for 45 min. At the same time, the mutant could grow normally under the condition of 60 ℃, while the sensitive strain could not. The mycelium growth rate of SdhDD95E mutants were faster than that of other mutant strains, while SdhB-H278Y mutants were slower than that of other mutant strains under treatment with various concentrations of NaCl. Glucose was important to the growth of SdhB-H278R mutants. The results showed that the biological characteristics and fitness of C. cassiicola with different boscalid-resistance were discrepant. The adaptability of SdhD-D95E mutants was improved, indicating that the mutant had stronger competitiveness in the field and was easy to form a dominant population. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant BASF SE submitted a request to the competent national authority in Greece to modify the existing maximum residue level (MRL) for the active substance boscalid in granate apples/pomegranates. The data submitted in support of the request were found to be sufficient to derive an MRL proposal for pomegranates. Adequate analytical methods for enforcement are available to control the residues of boscalid in the commodity under consideration at the validated limit of quantification (LOQ) of 0.01 mg/kg. Based on the risk assessment results, EFSA concluded that the long‐term intake of residues resulting from the use of boscalid according to the reported agricultural practice is unlikely to present a risk to consumer health. The reliable end points, appropriate for use in regulatory risk assessment are presented. [ABSTRACT FROM AUTHOR]