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Chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile, TPN, CAS: 1897-45-6) is a halogenated fungicide currently widely applied to a large variety of crops. Its carcinogenicity, embryo lethality, and high chronic oral toxicity in mammals, among other effects on a variety of organisms, has made its biodegradation of great interest. Chlorothalonil dehalogenase (Chd) from the bacterium Pseudomonas sp. CTN-3 offers a potential solution by catalyzing the first step in the degradation of chlorothalonil. Reported herein are active biomaterials of Chd when encapsulated in tetramethylorthosilicate (TMOS) gels using the sol–gel method (Chd/sol), alginate beads (Chd/alginate), and chitosan-coated alginate beads (Chd/chitosan). Both Chd/sol and Chd/chitosan increased protection from the endopeptidase trypsin as well as imparted stability over a pH range from 5 to 9. Chd/sol outperformed Chd/alginate and Chd/chitosan in long-term storage and reuse experiments, retaining similar activity to soluble Chd stored under similar conditions. All three materials showed a level of increased thermostability, with Chd/sol retaining >60% activity up to 70 °C. All materials showed activity in 40% methanol, suggesting the possibility for organic solvents to improve TPN solubility. Overall, Chd/sol offers the best potential for bioremediation of TPN using Chd. [ABSTRACT FROM AUTHOR]

Objective) To establish a method for simultaneous determination of chlorothalonil and its metabolite 4-hydroxychlorothalonil residues in animal-derived food by ultra-high performance liquid chromatography-tandem mass spectrometry. (Methods) The samples were extracted by oscillating with acetonitrile solution of 1% acetic acid, defatted with n-hexane, purified by matrix dispersible solid phase extractant (PSA, anhydrous magnesium sulfate), separated by Waters BEH C18 column under a gradient elution program using 0.1% formic acid aqueous solution and acetonitrile as the mobile phases. The anion multiple reaction monitoring model (MRM) of atmospheric pressure chemical ionization source (APCI) was used for the determination, and the matrix matching external standard method was used for quantitative determination. (Results) The linear relationships of chlorothalonil and 4-hydroxychlorothalonil were good in the range of 5- 500 μg/L, and the limits of quantitation were 0.005 mg/kg. The average recoveries of chlorothalonil and 4-hydroxychlorothalonil were 69.3%-111.0% and 65.3%-117.9%, respectively. The relative standard deviations of chlorothalonil and 4-hydroxychlorothalonil were 1.6%- 10.8% and 1.1%-9.0%, respectively. (Conclusion) The method is simple, rapid, sensitive, accurate and reliable for simultaneous determination of chlorothalonil and its metabolite 4-hydroxychlorothalonil in animal-derived food. [ABSTRACT FROM AUTHOR]

Abstract Pesticides are indispensable tools in modern agriculture for enhancing crop productivity. However, the inherent toxicity of pesticides raises significant concerns regarding human exposure, particularly among agricultural workers. This study investigated the exposure and associated risks of two commonly used pesticides in open-field pepper cultivation, namely, chlorothalonil and flubendiamide, in the Republic of Korea. We used a comprehensive approach, encompassing dermal and inhalation exposure measurements in agricultural workers during two critical scenarios: mixing/loading and application. Results revealed that during mixing/loading, dermal exposure to chlorothalonil was 3.33 mg (0.0002% of the total active ingredient [a.i.]), while flubendiamide exposure amounted to 0.173 mg (0.0001% of the a.i.). Conversely, dermal exposure increased significantly during application to 648 mg (chlorothalonil) and 93.1 mg (flubendiamide), representing 0.037% and 0.065% of the total a.i., respectively. Inhalation exposure was also evident, with chlorothalonil and flubendiamide exposure levels varying across scenarios. Notably, the risk assessment using the Risk Index (RI) indicated acceptable risk of exposure during mixing/loading but raised concerns during application, where all RIs exceeded 1, signifying potential risk. We suggest implementing additional personal protective equipment (PPE) during pesticide application, such as gowns and lower-body PPE, to mitigate these risks.

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department 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.)

Autoclaving eliminates microbial contamination during micropropagation, but the process is complex, time-consuming and expensive. Chemical sterilisation also effectively disinfects culture media and is relatively simple and cost-effective. Prior studies have focused on the effects of chemical sterilisation on bud induction, but the effects of sterilant on proliferation and rooting are unknown. We investigated the effect of sterilant on Acacia mangium × A. auriculiformis bud induction, rooting and subculture rooting. The optimal bud induction medium comprised 1/8 Murashige and Skoog medium $ + $ + 7 g l−1 agar $ + $ + 0.2 g l−1 chlorothalonil $ + $ + 0.5 mg l−1 6-benzylaminopurine. The maximum bud induction rate (99.54%) with zero contamination was achieved using the third to fifth stem segments collected in October and treated with 0.8 g l−1 carbendazim for 3 min. The maximum rooting rate (97.62%) was attained using a rooting medium consisting of 7 g l−1 agar $ + $ + 0.2 g l−1 chlorothalonil $ + $ + 1.5 mg l−1 indolebutyric acid $ + $ + 0.5 mg l−1 naphthaleneacetic acid. Proliferation ratio and subculture duration were positively correlated. The maximum proliferation rate (3.58%) was realised in the fourth subculture rooting. Chlorothalonil can effectively replace autoclaving of A. mangium × A. auriculiformis bud induction and rooting media. The present study provides insights for improving the rapid propagation method of Acacia sp. and a new direction for the development of micropropagation technology. [ABSTRACT FROM AUTHOR]

Chlorothalonil (CTL) is widely used in agricultural production and antifoulant additive globally due to its broad spectrum and non-systemic properties, resulting in its widespread existence in foods, soil and water. Extensive evidence demonstrated that exposure to CTL induced adverse effects on organisms and in particular its reproductive toxicity has been attracted public concern. However, the influences of CTL on oocyte maturation is mysterious so far. In this study, we documented the toxic effects of CTL on oocyte in vitro maturation and the related underlying mechanisms. Exposure to CTL caused continuous activation of spindle assembly checkpoints (SAC) which in turn compromised meiotic maturation in mouse oocyte, featured by the attenuation of polar body extrusion (PBE). Detection of cytoskeletal dynamics demonstrated that CTL exposure weakened the acetylation level of α-tubulin and impaired meiotic spindle apparatus, which was responsible for the aberrant state of SAC. Meanwhile, exposure to CTL damaged the function of mitochondria, inducing the decline of ATP content and the elevation of reactive oxygen species (ROS), which thereby induced early apoptosis and DNA damage in mouse oocytes. In addition, exposure to CTL caused the alteration of the level of histone H3 methylation, indicative of the harmful effects of CTL on epigenetic modifications in oocytes. Further, the CTL-induced oxidative stress activated mitogen-activated protein kinase (MAPK) pathway and injured the maturation of oocytes. In summary, exposure to CTL damaged mouse oocyte in vitro maturation via destroying spindle assembly, inducing oxidative stress and triggering MAPK pathway activation.

A mechanistic model was developed to simulate one-dimensional pesticide transport in two-stage vertical flow constructed wetland. The two pesticides taken under study were carbendazim and chlorothalonil. The water flow patterns within the constructed wetland were simulated using the Richards equation. Water content and vertical flux, which are the outputs of the substrate water flow model, were used to calculate the substrate moisture-related parameters and advection term in the solute transport model. The governing solute transport equation took into account a total of six processes: advection, molecular diffusion, dispersion, adsorption to the solid surface, degradation and volatilization. A total of 14 simulation cases, corresponding with available experimental data, were used to calibrate the model, followed by further simulations with standardized influent pesticide concentrations. The simulations indicated that the constructed wetland reached a steady state of pesticide removal after 7 days of operation. Two distinct water flow patterns emerged under saturated and unsaturated conditions. The patterns observed while varying the hydraulic loading rates were similar for each individual saturation condition. Two-factor ANOVA of the simulated data further revealed that the carbendazim and chlorothalonil removal was dependent on the hydraulic loading rates, but it was independent of the influent pesticide concentration. Analysis of the simulated pesticide removal showed that degradation emerged as the predominant removal process over time for both the pesticides. The model developed in this study can be an important tool for the design and construction of treatment wetlands for pesticide removal from wastewater. [ABSTRACT FROM AUTHOR]

It is very important to evaluate the immunotoxicity and molecular mechanisms of pesticides. In this study, difenoconazole and chlorothalonil were evaluated for immunotoxicity by using the human Jurkat T-cell line, and the EC50 were 24.66 and 1.17 mg/L, respectively. The joint exposure of difenoconazole and chlorothalonil showed a synergistic effect at low concentrations (lower than 10.58 mg/L) but an antagonistic effect at high concentrations (higher than 10.58 mg/L). With joint exposure at a concentration of EC10, the proportion of late apoptotic cells was 2.26- and 2.91-fold higher than that with exposure to difenoconazole or chlorothalonil alone, respectively. A transcriptomics analysis indicated that the DEGs for single exposure are associated with immunodeficiency disease. Single exposure to chlorothalonil was mainly involved in cation transportation, extracellular matrix organization, and leukocyte cell adhesion. Single exposure to difenoconazole was mainly involved in nervous system development, muscle contraction, and immune system processes. However, when the joint exposure dose was EC10, the DEGs were mainly involved in the formation of cell structures, but the DEGs were mainly involved in cellular processes and metabolism when the joint exposure dose was EC25. The results indicated that the immunotoxicological mechanisms underlying joint exposure to difenoconazole and chlorothalonil are different under low and high doses. [ABSTRACT FROM AUTHOR]

Glutathione plays a critical role in plant growth, development and response to stress. It is a major cellular antioxidant and is involved in the detoxification of xenobiotics in many organisms, including plants. However, the role of glutathione-dependent redox homeostasis and associated molecular mechanisms regulating the antioxidant system and pesticide metabolism remains unclear. In this study, endogenous glutathione levels were manipulated by pharmacological treatments with glutathione synthesis inhibitors and oxidized glutathione. The application of oxidized glutathione enriched the cellular oxidation state, reduced the activity and transcript levels of antioxidant enzymes, upregulated the expression level of nitric oxide and Ca2+ related genes and the content, and increased the residue of chlorothalonil in tomato leaves. Further experiments confirmed that glutathione-induced redox homeostasis is critical for the reduction of pesticide residues. RNA sequencing analysis revealed that miRNA156 and miRNA169 that target transcription factor SQUAMOSA-Promoter Binding Proteins (SBP) and NUCLEAR FACTOR Y (NFY) potentially participate in glutathione-mediated pesticide degradation in tomato plants. Our study provides important clues for further dissection of pesticide degradation mechanisms via miRNAs in plants.

Chlorothalonil is an organochlorine fungicide that blocks the respiratory process of cells and persists in agricultural products because it is used extensively to prevent fungal diseases. An analytical method of chlorothalonil using the modified QuEChERS method and gas chromatography– mass spectrometry (GC-MS/MS) was developed to analyze the residue in agricultural commodities distributed in Republic of Korea. Acetonitrile, including acetic acid and formic acid, was used to compare the extraction efficiency. The extraction and purification processes were established by comparing three versions of the QuEChERS method and various dispersive solid-phase extraction (d-SPE) combinations. Ultimately, 1% formic acid in acetonitrile with QuEChERS original salts and d-SPE (PSA, C18) were selected for the extraction and clean-up procedures for method validation and establishment. Five agricultural commodities, viz., brown rice, mandarin, soybean, pepper, and potato, were examined to validate the established method, which displayed excellent linearity, with a coefficient of determination of R2 = 0.9939–0.997 in the calibration curve range of 0.002–0.1 mg/kg. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.003 mg/kg and 0.01, respectively, for the method. The LOQ value satisfied the suitable level for the Positive List System (PLS). The mean recovery of chlorothalonil was 79.3–104.1%, and the coefficient of variation was <17.9% for intra- and inter-day precision at 0.01, 0.1, and 0.5 mg/kg. The matrix effects in the five commodities were confirmed by the ion suppression effects, except for brown rice, in which a medium enhancement effect was observed at 21.4%. Chlorothalonil was detected in eight apples, one watermelon, and one cucumber. Ultimately, chlorothalonil was detected in ten agricultural products. Thus, this analytical method could be used for the routine detection of chlorothalonil in agricultural products, and the data may be used to inform and improve current food policies. [ABSTRACT FROM AUTHOR]

The Ethiopian floriculture industry produces large amounts of wastewater, which requires treatment systems with lower retention times, higher hydraulic flow, and higher hydraulic loading rates (HLRs). Unsaturated vertical flow constructed wetlands (UVF-CWs), which represent these characteristics, have not been studied in depth for chlorothalonil remediation from wastewater. In this study, six UVF-CWs and nine pumping stations were organized into three experimental groups as three independent two-stage CW systems. The influent was pumped into the first vertical-flow stage, after which the effluent was collected and pumped into the second vertical-flow stage. The stage A and stage B effluents were tested for chlorothalonil removal at three different HLR of 50, 200, and 400 L d−1 m−2 and two influent chlorothalonil concentrations of 100 and 500 µg L−1. The chlorothalonil levels for the stage A effluent at an HLR of 50 L d−1 m−2 for both influent chlorothalonil concentrations were below the detection limit of 0.08 µg L−1. A maximum chlorothalonil concentration of 7.9 and 196 µg L−1 was observed in the stage A effluent for influent concentrations of 100 and 500 µg L−1, respectively. The chlorothalonil levels for the stage B effluent were all below the detection limit of 0.08 µg L−1. A final chlorothalonil removal efficiency of at least 99.9% was observed for both influent chlorothalonil concentrations at the three HLRs used. These results demonstrated that UVF-CWs represent a viable solution for chlorothalonil remediation in the Ethiopian floriculture industry. [ABSTRACT FROM AUTHOR]

This study investigated the degradation of two chlorothalonil formulations [Chlorcal 70% Wettable Powder (WP) and Open 72% Suspension Concentrate 72% (SC)]. The tested fungicides were stored at 54 ± 2°C for 14 days. During the different storage periods, samples were taken after 1, 3, 7, and 14 days to determine physical properties, evaluate the chemical stability of the active ingredient: Hexachlorobenzene as impurities by HPLC and fingerprint (GC/MS and IR), as well as the evaluation of their efficacy, by testing them against the mycelial growth of Fusarium solani and Botrytis cinerea under in vitro condition. The results indicated that Open 72% SC was the most effective fungicide against F. solani and B. cinerea it recorded the lowest EC50 value of 28.4 and 46.8 ppm respectively, followed by Chlorcal 70%WP with EC50 values of 42.9 and 59.4 ppm respectively. On the other hand, the effectiveness of tested fungicides deteriorated as the result of storage at 54 ± 2 ºC for 14 days with EC50 values increased from 28.4 to 130.9 and 46.8 to 278.1 in the case of Open 72% SC against F. solani and B. cinerea respectively, while the degradation efficiency of Chlorcal 70%WP was decreased at storage with EC50 values from 42.9 to 89.4 and 59.4 to 145.3 against these two fungi respectively. Chlorcal 70%WP was more stable at during storage and less effective against fungal pathogens and determination of chemical content (total soluble sugar; total protein; free amino acids) and some enzymes (amylase and catalase) activities of mycelium fungi. Potato dextrose (PD) media treated with chlorothalonil formulations induced a significant decrease in all components in each fungus except the catalase enzyme in the case of B. cinerea. The obtained results showed that active ingredients were 69.82%, 71.9% and reached 69.3%, and 70.75% after 14 days of storage at 54 ± 2 ºC for Chlorcal 70% WP, Open 72% SC, respectively. Also calculated half-life (T0.5) values for Chlorcal 70% WP, Open 72% SC were 1382.07 days and 614.035 days, respectively. This result refers that Chlorcal 70% WP is more stable than Open 72% SC after storage at 54 ± 2 oC for 14 days, whereas the amount of hexachlorobenzene was within the FAO limits for all sources before and after storage. Then the other tested GC / MS was used for the degradation of chlorothalonil fungicide, the two major degradation products in chlorothalonil were 2,5,6-trichloro- 4- hydroxyisophthalonitrile and 2,4,6-trichloroisophthalonitrile.

Wet bubble disease (WBD) is globally becoming a major problem in mushroom crops. The effectiveness of the application of different chemical (chlorothalonil, metrafenone and prochloraz-Mn) and Bacillus (B. subtilis and B. amyloliquefaciens strains) -based products for the control of WBD in artificially inoculated mushroom crops was studied. Six trials were carried out, with three different inoculum rates. The effect of fungicides on mushroom productivity and disease incidence was assessed. The effectiveness of the treatments is statistically related to the harshness of the disease. The greatest reductions in disease incidence were achieved after treatments with chemical fungicides, notably prochloraz-Mn. When the outbreak was strong, the low calculated incidence reduction values for metrafenone treatments advised against their application. The results also indicated the low effect of both bio-fungicides, at the doses and timing evaluated, for the control of this mushroom disease. [ABSTRACT FROM AUTHOR]

Postharvest senescence and disease development can reduce the nutritional value of fresh jujube fruit. Herein, four different disease-controlling agents (chlorothalonil, CuCl2, harpin and melatonin) were separately applied to fresh jujube fruit, and all improved postharvest quality (evaluated by disease severity, antioxidant accumulation and senescence) relative to controls. Disease severity was drastically inhibited by these agents, in the order chlorothalonil > CuCl2 > harpin > melatonin. However, chlorothalonil residues were detected even after storage for 4 weeks. These agents increased the activities of defense enzymes including phenylalanine ammonia-lyase, polyphenol oxidase, glutathione reductase and glutathione S-transferase, as well as accumulation of antioxidant compounds such as ascorbic acid, glutathione, flavonoids and phenolics, in postharvest jujube fruit. The enhanced antioxidant content and antioxidant capacity (evaluated by Fe3+ reducing power) was ordered melatonin > harpin > CuCl2 > chlorothalonil. All four agents significantly delayed senescence (evaluated by weight loss, respiration rate and firmness), with the effect ordered CuCl2 > melatonin > harpin > chlorothalonil. Moreover, treatment with CuCl2 also increased copper accumulation ~ threefold in postharvest jujube fruit. Among the four agents, postharvest treatment with CuCl2 could be considered most appropriate for improving postharvest jujube fruit quality under low temperature conditions without sterilization. [ABSTRACT FROM AUTHOR]

Background: Chlorothalonil and acetamiprid are chemical pesticides commonly used in agricultural production and have been shown to have negative effects on bee’s fitness. Despite many studies have revealed that honey bee (Apis mellifera L.) larvae are posting a high risk on exposure to pesticides, but the toxicology information of chlorothalonil and acetamiprid on bee larvae remain limited. Results: The no observed adverse effect concentration (NOAEC) of chlorothalonil and acetamiprid for honey bee larvae were 4 μg/mL and 2 μg/mL, respectively. Except for CarE, the enzymic activities of GST and P450 were not influenced by chlorothalonil at NOAEC, while chronic exposure to acetamiprid slightly increased the activities of the three tested enzymes at NOAEC. Further, the exposed larvae showed significantly higher expression of genes involved in a series of different toxicologically relevant process following, including caste development (Tor (GB44905), InR-2 (GB55425), Hr4 (GB47037), Ac3 (GB11637) and ILP-2 (GB10174)), immune system response (abaecin (GB18323), defensin-1 (GB19392), toll-X4 (GB50418)), and oxidative stress response (P450, GSH, GST, CarE). Conclusion: Our results suggest that the exposure to chlorothalonil and acetamiprid, even at concentrations below the NOAEC, showed potentially effects on bee larvae’s fitness, and more important synergistic and behavioral effects that can affect larvae fitness should be explored in the further. [ABSTRACT FROM AUTHOR]

It is very important to evaluate the immunotoxicity and molecular mechanisms of pesticides. In this study, difenoconazole and chlorothalonil were evaluated for immunotoxicity by using the human Jurkat T-cell line, and the EC50 were 24.66 and 1.17 mg/L, respectively. The joint exposure of difenoconazole and chlorothalonil showed a synergistic effect at low concentrations (lower than 10.58 mg/L) but an antagonistic effect at high concentrations (higher than 10.58 mg/L). With joint exposure at a concentration of EC10, the proportion of late apoptotic cells was 2.26- and 2.91-fold higher than that with exposure to difenoconazole or chlorothalonil alone, respectively. A transcriptomics analysis indicated that the DEGs for single exposure are associated with immunodeficiency disease. Single exposure to chlorothalonil was mainly involved in cation transportation, extracellular matrix organization, and leukocyte cell adhesion. Single exposure to difenoconazole was mainly involved in nervous system development, muscle contraction, and immune system processes. However, when the joint exposure dose was EC10, the DEGs were mainly involved in the formation of cell structures, but the DEGs were mainly involved in cellular processes and metabolism when the joint exposure dose was EC25. The results indicated that the immunotoxicological mechanisms underlying joint exposure to difenoconazole and chlorothalonil are different under low and high doses.

Among different novel technologies, sonochemistry is a sustainable emerging technology for food processing, preservation, and pesticide removal. The study aimed to probe the impact of high-intensity ultrasonication on chlorothalonil fungicide degradation, reduction pathway, and bioactive availability of spinach juice. The chlorothalonil fungicide-immersed spinach juice was treated with sonication at 360 W, 480 W, and 600 W, 40 kHz, for 30 and 40 min at 30 ± 1 °C. The highest reduction of chlorothalonil fungicide residues was observed at 40 min sonication at 600 W. HPLC-MS (high-performance liquid chromatography-mass spectroscopy) analysis revealed the degradation pathway of chlorothalonil and the formation of m-phthalonitrile, 3-cyno-2,4,5,6-tetrachlorobenamide, 4-dichloroisophthalonitrile, trichloroisophtalonitrile, 4-hydoxychlorothalonil, and 2,3,4,6-tetrachlorochlorobenzonitrile as degradation products. High-intensity sonication treatments also significantly increased the bioavailability of phenolic, chlorophyll, and anthocyanins and the antioxidant activity of spinach juice. Our results proposed that sonication technology has excellent potential in degrading pesticides through free radical reactions formation and pyrolysis. Considering future perspectives, ultrasonication could be employed industrially to reduce pesticide residues from agricultural products and enhance the quality of spinach juice.

This study investigated the degradation of two chlorothalonil formulations [Chlorcal 70% Wettable Powder (WP) and Open 72% Suspension Concentrate 72% (SC)]. The tested fungicides were stored at 54 ± 2°C for 14 days. During the different storage periods, samples were taken after 1, 3, 7, and 14 days to determine physical properties, evaluate the chemical stability of the active ingredient: Hexachlorobenzene as impurities by HPLC and fingerprint (GC/MS and IR), as well as the evaluation of their efficacy, by testing them against the mycelial growth of Fusarium solani and Botrytis cinerea under in vitro condition. The results indicated that Open 72% SC was the most effective fungicide against F. solani and B. cinerea it recorded the lowest EC50 value of 28.4 and 46.8 ppm respectively, followed by Chlorcal 70%WP with EC50 values of 42.9 and 59.4 ppm respectively. On the other hand, the effectiveness of tested fungicides deteriorated as the result of storage at 54 ± 2 °C for 14 days with EC50 values increased from 28.4 to 130.9 and 46.8 to 278.1 in the case of Open 72% SC against F. solani and B. cinerea respectively, while the degradation efficiency of Chlorcal 70%WP was decreased at storage with EC50 values from 42.9 to 89.4 and 59.4 to 145.3 against these two fungi respectively. Chlorcal 70%WP was more stable at during storage and less effective against fungal pathogens and determination of chemical content (total soluble sugar; total protein; free amino acids) and some enzymes (amylase and catalase) activities of mycelium fungi. Potato dextrose (PD) media treated with chlorothalonil formulations induced a significant decrease in all components in each fungus except the catalase enzyme in the case of B. cinerea. The obtained results showed that active ingredients were 69.82%, 71.9% and reached 69.3%, and 70.75% after 14 days of storage at 54 ± 2 °C for Chlorcal 70% WP, Open 72% SC, respectively. Also calculated half-life (T0.5) values for Chlorcal 70% WP, Open 72% SC were 1382.07 days and 614.035 days, respectively. This result refers that Chlorcal 70% WP is more stable than Open 72% SC after storage at 54 ± 2 oC for 14 days, whereas the amount of hexachlorobenzene was within the FAO limits for all sources before and after storage. Then the other tested GC / MS was used for the degradation of chlorothalonil fungicide, the two major degradation products in chlorothalonil were 2,5,6-trichloro-4-hydroxyisophthalonitrile and 2,4,6-trichloroisophthalonitrile. [ABSTRACT FROM AUTHOR]

Pesticides are extensively used in agriculture to prevent infestation of crops, control plant-associated diseases and pests, and increase crop productivity. With regards to typical agricultural practice, tank mixing of two or more plant protection products or the subsequent applications of herbicides, fungicides, and insecticides are common application strategies to improve pest control. Our study provides evidence that the fungicide mixture consisting of mancozeb, metalaxyl-M, and chlorothalonil, each applied according to their recommended field rates, retarded the degradation of the phenoxy herbicide 4-chloro-2-methylphenoxyacetic acid (MPCA) in soil. MCPA dissipation times were between 1.6 and 1.9 days without and 2.5–3.5 days with co-applied fungicides. Furthermore, the proportions of extractable residues, non-extractable residues, mineralization, volatile organic compounds, and MPCA metabolism were altered by the fungicide mixture, i.e., considerably lower amounts of the main transformation product of MCPA, 4-chloro-2-methylphenol, were formed. The effects induced by the fungicides persisted throughout the experiment. Our results demonstrate that the current situation of considering individual active substances in the authorization process for plant protection products could lead to a discrepancy in the exposure assessment for humans and the environment. For specifically these cases, this calls into question whether the legally required level of protection is provided. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the efficacy of fungicides for controlling anthracnose (Colletotrichum gloeosporioides) on peach palm (Bactris gasipaes var. gasipaes) seedlings in nursery beds and in newly planted peach palms in the field. The nursery experiment included two fungicide combinations: [thiophanate-methyl + chlorothalonil (TM + C) and pyraclostrobin + epoxiconazole (P + E)], three application intervals (7, 14, and 21 days), and an additional nontreated control. The two field experiments with newly planted peach palms tested the fungicide combinations TM + C at 15-day intervals for 12 months after transplanting, comparing to the control without fungicide application. The severity of anthracnose was assessed, and it was used for calculating the area under the disease progress curve (AUDPC). The fungicides TM + C and E + P applied at 7-days intervals were effective in the control of anthracnose in peach palm seedlings, resulting in the lowest severities and AUDPC. The fungicide TM + C reduced the maximum disease severity and AUDPC under field conditions. However, differences in the final severity of anthracnose and stem diameter were not significant compared to the control. Therefore, the use of fungicides for control of anthracnose in the field is not necessary. [ABSTRACT FROM AUTHOR]

Chlorothalonil is an organochlorine fungicide that blocks the respiratory process of cells and persists in agricultural products because it is used extensively to prevent fungal diseases. An analytical method of chlorothalonil using the modified QuEChERS method and gas chromatography– mass spectrometry (GC-MS/MS) was developed to analyze the residue in agricultural commodities distributed in Republic of Korea. Acetonitrile, including acetic acid and formic acid, was used to compare the extraction efficiency. The extraction and purification processes were established by comparing three versions of the QuEChERS method and various dispersive solid-phase extraction (d-SPE) combinations. Ultimately, 1% formic acid in acetonitrile with QuEChERS original salts and d-SPE (PSA, C18) were selected for the extraction and clean-up procedures for method validation and establishment. Five agricultural commodities, viz., brown rice, mandarin, soybean, pepper, and potato, were examined to validate the established method, which displayed excellent linearity, with a coefficient of determination of R2 = 0.9939–0.997 in the calibration curve range of 0.002–0.1 mg/kg. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.003 mg/kg and 0.01, respectively, for the method. The LOQ value satisfied the suitable level for the Positive List System (PLS). The mean recovery of chlorothalonil was 79.3–104.1%, and the coefficient of variation was

Vanilla planifolia is attacked by the fungus F. oxysporum f. sp. vanillae. Since there are no resistant genotypes available to producers, they opt for the use of synthetic fungicides to control the disease, however, there is no information on a possible resistance of the pathogen to these commercial fungicides. The goal of the work was to analyze the response of F. oxysporum strains, pathogenic (nine) and non-pathogenic (three) of V. planifolia, to three fungicides of the benzimidazole family and to chlorothalonil, as well as the genetic bases by studying the target proteins of these active ingredients, β-tubulin and GPDH. It was observed that the 12 strains studied were susceptible to the fungicides benomyl and carbendazim, while 11 of them were resistant to thiophanate methyl and nine to chlorothalonil. No relationship was found between the pathogenic character or the origin of the strains and the susceptibility to fungicides. It was found that resistance to thiophanate methyl is not conferred by a point mutation of the β-tubulin coding sequence, as previously hypothesized; apparently, it could be more related to the absence of protein motifs. No relationship was observed between variation in the gene GPDH with the resistance or susceptibility of the strains. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences 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.)

• Sublethal concentrations of β-endosulfan reduced tadpoles weight, neutrophil and lymphocyte count, while CORT levels increased. • Tadpoles exposed to chlorothalonil show an increase in counts of monocytes and lymphocytes; and accelerated the larval development. • A combination of stress factors increases the number of lymphocytes in the blood due to synergistic cytotoxicity. • Chlorothalonil has non-monotonic effects on various immune cells at low concentrations. • Predators produce variation in weight and length of the tadpoles. Pesticide exposure and its interaction with other natural stressors can play a role in amphibian population declines because disruptions in stress hormone regulatory mechanisms may inhibit immune responses during metamorphosis. Here, we determined the interactive effects of predation risk and sublethal concentration of two pesticides on immunological and physiological responses in tadpoles of the tropical frog Lithobates taylori. Using mesocosms, we used chronic exposure to three levels of chlorothalonil and β-endosulfan in the presence or absence of Odonate larvae. Our results show that β-endosulfan in high concentrations reduced the weight of the tadpoles and increased the neutrophil count and corticosterone (CORT) levels. Larval development was accelerated by high concentrations of chlorothalonil. Also, this pesticide in low and high concentrations increases the absolute values of lymphocytes. Tadpoles exposed to chlorothalonil increased the numbers of monocytes (in low concentrations), and lymphocytes (in high and low concentrations). The interactions of the low concentrations of both pesticides with and without the predator's presence also increased the number of lymphocytes. A combination of pesticides increases the number of lymphocytes in the blood due to synergistic cytotoxicity. This study proves that β- endosulfan elevates circulating CORT and thus generates physiological stress in tadpoles. Given that both pesticides are widely used within the distribution of L. taylori in Costa Rica, it is likely that tadpoles' development and immune function are altered by pesticide use. In combination with stressors such as emerging diseases and altered precipitation regimes, widespread agrochemical uses likely caused this species enigmatic decline in recent decades. [ABSTRACT FROM AUTHOR]

Mechanistic models are invaluable in ecological risk assessment (ERA) because they facilitate extrapolation of organism-level effects to population-level effects while accounting for species life history, ecology, and vulnerability. In this work, we developed a model framework to compare the potential effects of the fungicide chlorothalonil across four listed species of cyprinid fish and explore species-specific traits of importance at the population level. The model is an agent-based model based on the dynamic energy budget theory. Toxicokinetic-toxicodynamic sub-models were used for representing direct effects, whereas indirect effects were described by decreasing food availability. Exposure profiles were constructed based on hydroxychlorothalonil, given the relatively short half-life of parent chlorothalonil. Different exposure magnification factors were required to achieve a comparable population decrease across species. In particular, those species producing fewer eggs and with shorter lifespans appeared to be more vulnerable. Moreover, sequentially adding effect sub-models resulted in different outcomes depending on the interplay of life-history traits and density-dependent compensation effects. We conclude by stressing the importance of using models in ERA to account for species-specific characteristics and ecology, especially when dealing with listed species and in accordance with the necessity of reducing animal testing. [ABSTRACT FROM AUTHOR]

To gain better knowledge of the effects of residual chlorothalonil on soil characteristics and soil microbial communities, we evaluated the dissipation of chlorothalonil and the effects of different chlorothalonil concentrations on soil respiration, enzyme activities, and microbial community structure in yellow–brown loam soils. Bacterial and fungal soil communities were examined using traditional plate counting and polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) methods. Soil properties and the results of DGGE band analysis were both used to estimate the status of the soil microbial ecosystem. The results show that residual chlorothalonil has considerable effects on soil respiration, enzymatic activities, and microbial community structure. In particular, soil respiration and phosphatase activities were increased, while saccharase activity, microbial biomass, and microbial community diversity were decreased by increasing levels of chlorothalonil treatment. Correlation analyses revealed that the application of chlorothalonil was significantly correlated with the change of the soil respiration, urease activity, sucrase activity, soil culturable bacteria, and culturable fungi biomass. We conclude that residual chlorothalonil is directly related to soil respiration, enzyme activities, and microbial community structure. [ABSTRACT FROM AUTHOR]

Chlorothalonil is widely used to control fungal diseases and it is usually detected in the environment. Phototransformation is an important process to remove chlorothalonil from the aquatic environment. The mesoporous ammonium phosphotungstate/silica catalyst (NH4PW/SiO2) was synthesized from cetyl trimethyl ammonium bromide (CTAB) and tetraethoxysilane (TEOS) as raw materials by adding insoluble ammonium phosphotungstate into the alkaline alcohol–water system by the sol-gel method. The structure of NH4PW/SiO2 was characterized by X-ray diffractometry (XRD), Brunauer–Emmett–Teller (BET) and Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity of NH4PW/SiO2 was evaluated by using the organic pesticide chlorothalonil as a model reactant. The result indicated that when the dosage of NH4PW/SiO2 is 0.02 g, the illumination is 180 min, the concentration of chlorothalonil is 5 mg/L, pH = 5, the degradation effect is better, and the degradation rate reaches 83.23%. The results contributed to the understanding of chlorothalonil phototransformation and the potential of mesoporous SiO2 to effectively enhance the photocatalytic activity of NH4PW (64.16%) to reduce aquatic toxicity and pollution by chlorothalonil.

ObjectivesThis study aimed to provide an assessment of chlorothalonil's possible carcinogenic risk posed to the public. In combination and comparison with the non-carcinogenic risk, the results hopefully could provide useful insights, early warning, and references for policy formulation.MethodsThis study firstly investigated the occurrence of chlorothalonil on selected key vegetables for different scenarios, and then conducted an exposure assessment with officially published data. Lastly, both the non-carcinogenic and carcinogenic risk of chlorothalonil were calculated by using Monte-Carlo simulation.ResultsEven though mean non-carcinogenic risks of chlorothalonil for all scenarios were below threshold value, the mean carcinogenic risks for maximum-risk scenario and most-likely risk scenario were mostly above threshold value. High probabilities of exceedance of threshold value existed for carcinogenic risk under all scenarios.ConclusionPotential threat to public health existed for conventionally ‘safe' pesticide if considering the possible carcinogenicity. Extra caution should be taken and the potential carcinogenic effects should be included into consideration for better protection of public health during the policy formulation process.

Bordetella sp. CTN-16 (GenBank FJ598326) can degrade chlorothalonil (CTN) but not carbendazim (MBC), and Microbacterium sp. MBC-3 (GenBank OK667229) can degrade MBC but not CTN. A functional strain BD2 was obtained by protoplast fusion of CTN-16 and MBC-3 to generate a fusant with improved degradation efficiency of CTN and MBC. Fusant-BD2 with eighth transfer on a medium containing CTN and two antibiotics was obtained. To identify and confirm the genetic relationship between parental strains and fusion strain BD2, scanning electron microscopy (SEM), random amplified polymorphic DNA (RAPD), and 16S ribosomal RNA (rRNA) gene sequences analysis were carried out. SEM analysis illustrated BD2 and its parents had some slight differences in the cell morphology. Fusant-BD2 not only possessed the same bands as parental strains but also had its specific bands analyzed through RAPD. The genetic similarity indices for BD2 and its parental strains CTN-16 and MBC-3 are 0.571 and 0.428, respectively. The degradation rates of CTN and MBC were 79.8% and 65.2% in the inorganic salt solution containing 50 mg·L−1 CTN and 50 mg·L−1 MBC, respectively, and the degradation efficiencies were better than the parental strains CTN-16 and MBC-3. This study provides a prospect for the application of fusion strain BD2 in bioremediation of CTN and MBC contaminated sites. [ABSTRACT FROM AUTHOR]

Abstract Background Unrestricted use of pesticides in agriculture is likely to increase insecticide resistance in mosquito vectors. Unfortunately, strategies for managing insecticide resistance in agriculture and public health sectors lack integration. This study explored the types and usage of agricultural pesticides, and awareness and management practices among retailers and farmers in Ulanga and Kilombero districts in south-eastern Tanzania, where Anopheles mosquitoes are resistant to pyrethroids. Methods An exploratory sequential mixed-methods approach was employed. First, a survey to characterize pesticide stocks was conducted in agricultural and veterinary (agrovet) retail stores. Interviews to assess general knowledge and practices regarding agricultural pesticides were performed with 17 retailers and 30 farmers, followed by a survey involving 427 farmers. Concurrently, field observations were done to validate the results. Results Lambda-cyhalothrin, cypermethrin (both pyrethroids) and imidacloprids (neonicotinoids) were the most common agricultural insecticides sold to farmers. The herbicide glyphosate (amino-phosphonates) (59.0%), and the fungicides dithiocarbamate and acylalanine (54.5%), and organochlorine (27.3%) were also readily available in the agrovet shops and widely used by farmers. Although both retailers and farmers had at least primary-level education and recognized pesticides by their trade names, they lacked knowledge on pest control or proper usage of these pesticides. Most of the farmers (54.4%, n = 316) relied on instructions from pesticides dealers. Overall, 93.7% (400) farmers practised pesticides mixing in their farms, often in close proximity to water sources. One-third of the farmers disposed of their pesticide leftovers (30.0%, n = 128) and most farmers discarded empty pesticide containers into rivers or nearby bushes (55.7%, n = 238). Conclusion Similarities of active ingredients used in agriculture and malaria vector control, poor pesticide management practices and low-levels of awareness among farmers and pesticides retailers might enhance the selection of insecticide resistance in malaria vectors. This study emphasizes the need for improving awareness among retailers and farmers on proper usage and management of pesticides. The study also highlights the need for an integrated approach, including coordinated education on pesticide use, to improve the overall management of insecticide resistance in both agricultural and public health sectors.

The adsorption, degradation and leaching characteristics of chlorothalonil in two representative soil were studied using simulated soil degradation and soil column leaching. The results showed that the adsorption of chlorothalonil in clay and sandy soil can be characterized by the Freundlich equation. The adsorption coefficient (K) was 6.7158 and 1.2568, respectively. Both soils were physical adsorption. The residual degradation kinetics of chlorothalonil in both soils met the first-order kinetics degradation equation. As the concentration of chlorothalonil increased, the higher the residual amount of chlorothalonil in the soil, the slower the degradation rate and the longer the half-life. In the soil column, chlorothalonil was not easy to move and migrate in the two soil columns. The highest residual residues were in the range of 0 to 10 cm (the topmost), and then a decrease in order. The correlation analysis showed that the adsorption and leaching of chlorothalonil in the two soils may be affected by a combination of factors such as soil organic matter content, clay content, cation exchange capacity, and soil pH value, it posed a great risk of groundwater contamination, so should be given serious attention.

Bordetella sp. CTN-16 (GenBank FJ598326) can degrade chlorothalonil (CTN) but not carbendazim (MBC), and Microbacterium sp. MBC-3 (GenBank OK667229) can degrade MBC but not CTN. A functional strain BD2 was obtained by protoplast fusion of CTN-16 and MBC-3 to generate a fusant with improved degradation efficiency of CTN and MBC. Fusant-BD2 with eighth transfer on a medium containing CTN and two antibiotics was obtained. To identify and confirm the genetic relationship between parental strains and fusion strain BD2, scanning electron microscopy (SEM), random amplified polymorphic DNA (RAPD), and 16S ribosomal RNA (rRNA) gene sequences analysis were carried out. SEM analysis illustrated BD2 and its parents had some slight differences in the cell morphology. Fusant-BD2 not only possessed the same bands as parental strains but also had its specific bands analyzed through RAPD. The genetic similarity indices for BD2 and its parental strains CTN-16 and MBC-3 are 0.571 and 0.428, respectively. The degradation rates of CTN and MBC were 79.8% and 65.2% in the inorganic salt solution containing 50 mg·L−1 CTN and 50 mg·L−1 MBC, respectively, and the degradation efficiencies were better than the parental strains CTN-16 and MBC-3. This study provides a prospect for the application of fusion strain BD2 in bioremediation of CTN and MBC contaminated sites.

Glutathione (GSH) biosynthesis and regeneration play a significant role in the metabolism of chlorothalonil (CHT) in tomatoes. However, the specific regulatory mechanism of GSH in the degradation of CHT remains uncertain. To address this, we investigate the critical regulatory pathways in the degradation of residual CHT in tomatoes. The results revealed that the detoxification of CHT residue in tomatoes was inhibited by buthionine sulfoximine and oxidized glutathione pretreatment, which increased by 26% and 46.12% compared with control, respectively. Gene silencing of γECS, GS, and GR also compromised the CHT detoxification potential of plants, which could be alleviated by GSH application and decreased the CHT accumulation by 33%, 25%, and 21%, respectively. Notably, it was found that the jasmonic acid (JA) pathway participated in the degradation of CHT regulated by GSH. CHT residues reduced by 28% after application of JA. JA played a role downstream of the glutathione pathway by promoting the degradation of CHT residue in tomatoes via nitric oxide signaling and improving the gene expression of antioxidant and detoxification-related enzymes. This study unveiled a crucial regulatory mechanism of GSH via the JA pathway in CHT degradation in tomatoes and offered new insights for understanding residual pesticide degradation.

This document is a correction notice for an article titled "Exposure and risk assessment for agricultural workers during chlorothalonil and flubendiamide treatments in pepper fields." The original article contained errors in Table 3, specifically in the values for the "ADE (μg day−1)c" row for chlorothalonil and flubendiamide. The correct values have been provided in the correction notice. The authors of the article are Deuk-Yeong Lee, Jong-Wook Song, Ji-Young An, Yeong-Jin Kim, Jong-Su Seo, and Jong-Hwan Kim. [Extracted from the article]

Pesticides are extensively used in agriculture to prevent infestation of crops, control plant-associated diseases and pests, and increase crop productivity. With regards to typical agricultural practice, tank mixing of two or more plant protection products or the subsequent applications of herbicides, fungicides, and insecticides are common application strategies to improve pest control. Our study provides evidence that the fungicide mixture consisting of mancozeb, metalaxyl-M, and chlorothalonil, each applied according to their recommended field rates, retarded the degradation of the phenoxy herbicide 4-chloro-2-methylphenoxyacetic acid (MPCA) in soil. MCPA dissipation times were between 1.6 and 1.9 days without and 2.5–3.5 days with co-applied fungicides. Furthermore, the proportions of extractable residues, non-extractable residues, mineralization, volatile organic compounds, and MPCA metabolism were altered by the fungicide mixture, i.e., considerably lower amounts of the main transformation product of MCPA, 4-chloro-2-methylphenol, were formed. The effects induced by the fungicides persisted throughout the experiment. Our results demonstrate that the current situation of considering individual active substances in the authorization process for plant protection products could lead to a discrepancy in the exposure assessment for humans and the environment. For specifically these cases, this calls into question whether the legally required level of protection is provided.

Background: Tree bark measurements conducted between 2014 and 2017 in a biosphere reserve in Germany have indicated the presence of pesticides from conventional agriculture in ambient air. In the present study, we quantified pesticides and related substances in ambient air at 69 sites using passive air samplers and ventilation filter mats. It is, to our knowledge, so far the most comprehensive data set on pesticides and their related products in ambient air in Germany. Results: Samples were collected in 2019 and analysed for over 500 substances. One hundred and nine (109) were detected, including 28 that are not approved for use in Germany. In each sampling site, we identified one to 36 substances, including locations such as national parks and forests. Here, the presence of pesticides is not expected, e.g., on the highest mountain top in the national park "Harz" (13 substances) and in the "Bavarian Forest" (six substances). Glyphosate was recorded in every sample. More than half of passive air samplers contained chlorothalonil, metolachlor, pendimethalin, terbuthylazine, prothioconazole-desthio, dimethenamid, prosulfocarb, flufenacet, tebuconazole, aclonifen, chlorflurenol, hexachlorobenzene (HCB), and γ-hexachlorocyclohexane (γ-HCH). Filter mats also contained boscalid. The statistical analysis showed that landscape classification and agricultural intensity were the primary factors influencing the number of substances detected in ambient air. Location, such as protected areas or regions of organic farming, had only a small effect on the number of substances recorded. Medium- and long-range transport likely accounts for these findings. Extending the current sampling method will probably detect more pesticides than the data currently suggest. Conclusions: Airborne pesticide mixtures are ubiquitous in Germany, which is particularly concerning for glyphosate, pendimethalin, and prosulfocarb. Deposition of these pesticides on organic products may disqualify them from the market, resulting in economic losses to farmers. Air concentrations of pesticides are a relevant issue and must be reduced. [ABSTRACT FROM AUTHOR]

Chlorothalonil is a widespread non-systemic fungicide used for the control of fungal infections in agriculture of vegetables and fruits. Due to the widespread use of chlorothalonil, chlorothalonil has been detected in all environmental systems, which poses potential risks to human health. The genotoxic effects of the fungicide Chlorothalonil were analyzed in cultured human peripheral lymphocytes by use of cytogenetic parameters including chromosomal aberrations, sister chromatid exchange and mitotic index. Blood samples were obtained from two healthy Non-smoker volunteers (aged 25 to 26 year old). Human lymphocytes were treated with four different concentrations of Chlorothalonil (1, 5, 20, and 50 µg/mL). The results of this study showed that Chlorothalonil significantly increased the frequency of chromosomal aberrations and sister chromatid exchange compared to the negative control. Moreover, chlorothalonil significantly decreased the mitotic value at all concentrations. Current findings show that Chlorothalonil is clastogenic and induces in vitro DNA damage in human lymphocytes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) 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.)

Population declines were documented in multiple ruminant species in Montana and surrounding states starting in 1995. While weather, food sources, and predation certainly contributed, the declines were often attributed, at least partly, to unexplained factors. Use of teratogenic agrichemicals, notably neonicotinoid insecticides, fungicides, and glyphosate-based herbicides, massively increased regionally in 1994–96. The question explored in this review is whether this vastly increased use of these teratogenic pesticides might have contributed to observed population declines. We provide references and data documenting that specific developmental malformations on vertebrates can be associated with exposure to one or more of these agrichemicals. These pesticides are known to disrupt thyroid and other hormonal functions, mitochondrial functions, and biomineralization, all of which are particularly harmful to developing fetuses. Exposures can manifest as impaired embryonic development of craniofacial features, internal and reproductive organs, and musculoskeletal/integumental systems, often resulting in reproductive failure or weakened neonates. This paper reviews: a) studies of ruminant populations in the region, especially elk and white-tailed deer, prior to and after 1994; b) published and new data on underdeveloped facial bones in regional ruminants; c) published and new data on reproductive abnormalities in live and necropsied animals before and after 1994; and d) studies documenting the effects of exposures to three of the most applied teratogenic chemicals. While answers to the question posed above are complex and insufficient evidence is available for definitive answers, this review provides ideas for further consideration. [Display omitted] • Teratogenic agrichemical use (imidacloprid, chlorothalonil, and glyphosate-based herbicides) increased regionally in 1994–96. • Vitality of Cervus canadensis calves declined between 1990–92 and 1997–99 in central Wyoming. • Calf/cow ratios in Alces alces declined in central Wyoming beginning in the mid-1990s. • Reproductive abnormalities and underdeveloped facial bones were discovered in Odocoileus virginianus fawns in spring 1995. • Similar abnormalities and reduced vitality were found in Odocoileus virginianus experimentally exposed to imidacloprid. [ABSTRACT FROM AUTHOR]

Chlorothalonil (CTL), an organochloride fungicide applied for decades worldwide, has been found to be present in various matrixes and even accumulates in humans or other mammals through the food chain. Its high residue and diffusion in the environment have severely affected food security and public health. More and more research has considered CTL as a possible toxin to environmental non-target organisms, via influencing multiple systems such as metabolic, developmental, endocrine, genetic, and reproductive pathways. Aquatic organisms and amphibians are the most vulnerable species to CTL exposure, especially during the early period of development. Under experimental conditions, CTL can also have toxic effects on rodents and other non-target organisms. As for humans, CTL exposure is most often reported to be relevant to allergic reactions to the skin and eyes. We hope that this review will improve our understanding of the hazards and risks that CTL poses to non-target organisms and find a strategy for rational use. [Display omitted] • Chlorothalonil has high residues in the environment. • Chlorothalonil has multiple potential exposure routes to non-target animals and humans. • Chlorothalonil exposure has multiple toxic targets in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) 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.)

Numerous threats are putting pollinator health and essential ecosystem pollination services in jeopardy. Although individual threats are widely studied, their co-occurrence may exacerbate negative effects, as posited by the multiple stressor hypothesis. A prominent branch of this hypothesis concerns pesticide–pathogen co-exposure. A landscape analysis demonstrated a positive association between local chlorothalonil fungicide use and microsporidian pathogen (Nosema bombi) prevalence in declining bumblebee species (Bombus spp.), suggesting an interaction deserving further investigation. We tested the multiple stressor hypothesis with field-realistic chlorothalonil and N. bombi exposures in worker-produced B. impatiens microcolonies. Chlorothalonil was not avoided in preference assays, setting the stage for pesticide–pathogen co-exposure. However, contrary to the multiple stressor hypothesis, co-exposure did not affect survival. Bees showed surprising tolerance to Nosema infection, which was also unaffected by chlorothalonil exposure. However, previously fungicide-exposed infected bees carried more transmission-ready spores. Our use of a non-declining bumblebee and potential higher chlorothalonil exposures under some scenarios could mean stronger individual or interactive effects in certain field settings. Yet, our results alone suggest consequences of pesticide co-exposure for pathogen dynamics in host communities. This underlies the importance of considering both within- and between-host processes when addressing the multiple stressor hypothesis in relation to pathogens. [ABSTRACT FROM AUTHOR]

The adsorption, degradation and leaching characteristics of chlorothalonil in two representative soil were studied using simulated soil degradation and soil column leaching. The results showed that the adsorption of chlorothalonil in clay and sandy soil can be characterized by the Freundlich equation. The adsorption coefficient (K) was 6.7158 and 1.2568, respectively. Both soils were physical adsorption. The residual degradation kinetics of chlorothalonil in both soils met the first-order kinetics degradation equation. As the concentration of chlorothalonil increased, the higher the residual amount of chlorothalonil in the soil, the slower the degradation rate and the longer the half-life. In the soil column, chlorothalonil was not easy to move and migrate in the two soil columns. The highest residual residues were in the range of 0 to 10 cm (the topmost), and then a decrease in order. The correlation analysis showed that the adsorption and leaching of chlorothalonil in the two soils may be affected by a combination of factors such as soil organic matter content, clay content, cation exchange capacity, and soil pH value, it posed a great risk of groundwater contamination, so should be given serious attention. [ABSTRACT FROM AUTHOR]

Abstract The applicants Syngenta Crop Protection, UPL Europe Ltd. and Oxon Italia S.p.A. submitted requests to the competent national authority in the Netherlands to evaluate the confirmatory data for chlorothalonil that were identified in the framework of the MRL review under Article 12 of Regulation (EC) No 396/2005 as not available; in addition, Syngenta and UPL submitted requests for modifications of existing MRLs. Considering the recent decision on the non‐approval of chlorothalonil, the requests for amending existing MRLs to reflect intended EU uses for chlorothalonil and confirmatory data for EU uses became obsolete. EFSA focused therefore its assessment on the import tolerances and on general information on the analytical method required to enforce legal limits for chlorothalonil and its metabolite SDS‐3701 (R182281). Analytical methods for enforcement are available to control the residues of chlorothalonil and SDS‐3701 in plant matrices at the validated LOQ of 0.01 mg/kg; data on the extraction efficiency for high oil content matrices as requested in the MRL review were not provided. This data gap is relevant for the import tolerance for peanuts. The data submitted in support of import tolerances were found to be sufficient to derive MRL proposals for chlorothalonil and SDS‐3701 for bagged bananas, papayas and peanuts. Studies investigating the effect of high temperature processing on the magnitude of SDS‐3701 in processed products are not available. Based on exposure calculations for chlorothalonil, EFSA concluded that the long‐term intake of residues resulting from the use of chlorothalonil according to the reported agricultural practices is unlikely to present a risk to consumers. For papaya, an acute intake concern was noted for chlorothalonil, while for banana and peanuts, the expected short‐term intake of chlorothalonil residues was below the toxicological reference value. For the metabolite SDS‐3701, the toxicological profile is not fully elucidated, and therefore, toxicological reference values could not be derived. Hence, for this metabolite, the consumer risk assessment cannot be finalised.

Abstract Background Open tissue culture technique could be simplified by using different bacteriostatic agents. There is a great difference in the bacteriostatic effects of different antimicrobial agents on various explants. However, there is no report about the effective bacteriostatic agent for open tissue culture of Acacia auriculiformis. Results We carried out the bud induction trials under open conditions to screen out an effective antibacterial agent for open tissue culture of A. auriculiformis. The results showed that the suitable type and concentration of bacteriostatic agent was 0.2 g L−1 Chlorothalonil, and the suitable explant type was middle shoot section with leaves (the shoot section with third to fifth axillary bud). The treatment of 0.8 g L−1 Carbendazim for 3 min was the most suitable strategy for explants disinfection, and October was the best time for explants collection. The suitable bud induction medium was 1/8 MS + agar 7 g L−1 + Chlorothalonil 0.2 g L−1 + 6-BA 1.5 mg L−1, and the bud induction rate was 99.54%. Conclusions Our results revealed that Chlorothalonil is an effective bacteriostatic agent for bud induction of A. auriculiformis under open condition. These results would be very helpful for further establishment of open tissue culture technology for A. auriculiformis.

Asian soybean rust (Phakopsora pachyrhizi) is the main disease that affects soybean in Brazil. Fungicide applications are the main control method, but they can be influenced by the occurrence of rain. We aimed to study the control of Asian soybean rust in response to the occurrence of simulated rainfall at different times after fungicide application. The penetrant fungicides trifloxystrobin + prothioconazole (60 + 70 g a.i. ha-1) and azoxystrobin + benzovindiflupyr (60 + 30 g a.i. ha-1) and the nonpenetrant fungicides mancozeb (1,500 g a.i. ha-1), chlorothalonil (1,440 g a.i. ha-1), and copper oxychloride (672 g a.i. ha-1) were tested using two spray volumes: 70 and 150 L ha-1. Rain was simulated from 30 to 240 minutes after fungicide application. Soybean leaflets were collected and inoculated with a spore suspension of P. pachyrhizi (5.0 x 104 mL-1) and incubated in plastic boxes for 20 days. The trials were repeated twice. Nonpenetrant fungicides were more susceptible to rain washing, mainly when the 70 L ha-1 spray volume was used. For the penetrative fungicides, the best control percentages were obtained when the rainfall occurred between 120 and 180 minutes after application, while the protective fungicides had the best control percentages when the rainfall occurred approximately 240 minutes after application. The Asian rust control is affected by the characteristics of the fungicide applied, by the time interval between fungicide application and rain occurrence and by the spray volume. [ABSTRACT FROM AUTHOR]

The applicants Syngenta Crop Protection, UPL Europe Ltd. and Oxon Italia S.p.A. submitted requests to the competent national authority in the Netherlands to evaluate the confirmatory data for chlorothalonil that were identified in the framework of the MRL review under Article 12 of Regulation (EC) No 396/2005 as not available; in addition, Syngenta and UPL submitted requests for modifications of existing MRLs. Considering the recent decision on the non‐approval of chlorothalonil, the requests for amending existing MRLs to reflect intended EU uses for chlorothalonil and confirmatory data for EU uses became obsolete. EFSA focused therefore its assessment on the import tolerances and on general information on the analytical method required to enforce legal limits for chlorothalonil and its metabolite SDS‐3701 (R182281). Analytical methods for enforcement are available to control the residues of chlorothalonil and SDS‐3701 in plant matrices at the validated LOQ of 0.01 mg/kg; data on the extraction efficiency for high oil content matrices as requested in the MRL review were not provided. This data gap is relevant for the import tolerance for peanuts. The data submitted in support of import tolerances were found to be sufficient to derive MRL proposals for chlorothalonil and SDS‐3701 for bagged bananas, papayas and peanuts. Studies investigating the effect of high temperature processing on the magnitude of SDS‐3701 in processed products are not available. Based on exposure calculations for chlorothalonil, EFSA concluded that the long‐term intake of residues resulting from the use of chlorothalonil according to the reported agricultural practices is unlikely to present a risk to consumers. For papaya, an acute intake concern was noted for chlorothalonil, while for banana and peanuts, the expected short‐term intake of chlorothalonil residues was below the toxicological reference value. For the metabolite SDS‐3701, the toxicological profile is not fully elucidated, and therefore, toxicological reference values could not be derived. Hence, for this metabolite, the consumer risk assessment cannot be finalised. [ABSTRACT FROM AUTHOR]