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Grape white rot is a destructive fungal disease caused by the pathogenic fungus Coniella vitis. The sensitivity of C. vitis to fluazinam was tested to select an efficient fungicide to control this disease. Furthermore, the baseline sensitivity of C. vitis populations to fluazinam was established based on the EC50 of 62 C. vitis strains collected from different regions in which grapevines are grown in China. The C. vitis populations were extremely sensitive to fluazinam. The efficiency of fluazinam to grape white rot was determined with detached grapevine leaves. Fluazinam was highly effective in controlling this disease. Moreover, the risk of the C. vitis strains developing resistance to fluazinam was assessed with five mutant strains resistant to fluazinam obtained by a fungicide selection method in the laboratory. The fluazinam‐resistant mutant strains were deficient in their hyphal growth, stress and virulence compared with the parental strain. This led to the conclusion that the C. vitis populations are highly sensitive to fluazinam, and C. vitis is unlikely to develop resistance to fluazinam under natural conditions. Thus, fluazinam is a potential fungicide to efficiently control grape white rot. [ABSTRACT FROM AUTHOR]

【Objective】The study aimed to clarify the degradation behavior and residual risk of fluazinam on Pamax notoginseng,and to provide a theoretical busis for the sate use of fluazinam.【Method】In 2018, controlled field application of fluazinam on P. notoginsengwere carried out inexperimental sites in Zhanyi, Shilin, Mile and Qiubei of Yunnan province. To detect and quantify fluazinamin P. notoginseng, an ultra-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method was established.【Result】The recovery efficiency of fluazinam in P. notoginseng and soil ranged from 82% to 103% with relative standard deviations（RSDs） of 1%-13% and limits of quantification（LOQ） of 0.01-0.02 mg/kg. The results of dissipation dynamic experiments indicated that the half-lifeof fluazinam in P. notoginseng plants were 6.5-7.4 days, and the half-lifein soils were 20.0-30.1 days, but the degradation of fluazinam in rhizosphere soils and roots of P. notoginseng were not consistent with the first-order kinetic model. The ultimate residue experiments showed that 50% fluazinam suspension applied at doses of 250 g/hm²and 375 g/hm² for 3-4 times with an interval of 7 days, at 7, 14, and 21 days after the last application the residues of fluazinam were below 1 mg/kg and 2 mg/kg in rhizome and root hair, respectively. The results of the dietary intake risk assessment revealed that the national estimated daily intake（NEDI） of fluazinam was 0.45 mg, with a risk quotient（RQ） of 71.4%, will be a posean unacceptable risk to the health of the general population. 【Conclusion】Fluazinam is easy to be degraded in crops and environment. At present, the Maximum Residue Level（MRL values） of fluazinam isset at 1 and 2 mg/kg in rhizome and root hair of P. notoginseng in China, respectively. When using 50% fluazinam suspension to control P. notoginseng diseases, it is recommended to apply at the most effective dose of 250 g/hm² and up to 3 times, and the safe pre-harvest interval is 7 days. [ABSTRACT FROM AUTHOR]

Fluazinam (FZN) is a dinitroaniline fungicide. To evaluate the environmental risk of FZN in aquatic environments and ascertain the potential danger to typical aquatic organisms in China, the acute toxicity of FZN to representative aquatic organisms, including Brachydanio rerio, Chlorella vulgaris Beij., Daphnia magna Straus, and Xenopus laevis, was measured, and its bioaccumulation properties in Brachydanio rerio were further investigated. The results showed that the acute toxicity of FZN to Brachydanio rerio and Xenopus laevis is extremely high, and the bioaccumulation factor BCF8d of FZN in Brachydanio rerio ranges between 2287 and 3570, implying that it has high bioaccumulation properties. FZN poses a strong environmental risk for aquatic organisms and possesses great bioaccumulation properties, which may cause pollution to aquatic environments. [ABSTRACT FROM AUTHOR]

BACKGROUND Citrus is one of the most important fruit crops worldwide. Fluazinam is a fungicide that is used to control fungal diseases, and its dissipation and residue in citrus fruits should be studied. RESULTS: A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure combined with gas chromatography with an electron capture detector (GC‐ECD) has been developed. The fortified recoveries ranged from 82.1% to 105.9%, with relative standard deviations (RSDs) of less than 5.7%. Fluazinam dissipated relatively quickly following first‐order kinetics, with a half‐life of 8.5–9.5 days. The experiments on the terminal residue of fluazinam in citrus were conducted at six locations in China, and the risk quotient (RQ) method was applied to citrus fruits for dietary exposure risk assessment based on the terminal residue test. The RQs of fluazinam at three preharvest intervals (PHIs) (21, 28, and 35 days) were all less than 100%, which is an acceptable level for human consumption. The present study provides a reference for the establishment of maximum residue limit (MRL) for fluazinam in citrus. CONCLUSIONS: The dissipation and residues of fluazinam in citrus were monitored. The half‐life of less than 10 days showed that fluazinam could degrade relatively easily in citrus. The risk assessment also indicated the intake safety of fluazinam in citrus. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Grey mould, caused by the fungus Botrytis cinerea Pers ex Fr., is a very destructive and important disease worldwide. Fluazinam is a phenylpyridinamine fungicide with broad‐spectrum activities. The baseline sensitivity of B. cinerea to fluazinam is yet to be established in Henan Province, China. In this study, a total of 117 field isolates of B. cinerea were collected from 49 commercial greenhouses in different locations of Henan Province, in 2016, and the sensitivities of these isolates to fluazinam were determined based on mycelial growth. The effective concentration for 50% (EC50) values ranged from 0.0038 to 0.0441 μg/ml, and the mean EC50 value was 0.0201 ± 0.0081 μg/ml for mycelial growth. The frequency distribution range presented a unimodal curve. To define the cross‐resistance relationships, the linear correlation coefficients of the EC50 values between fluazinam and carbendazim, procymidone, pyrimethanil or boscalid were analysed. The results showed that no correlation was observed between fluazinam and the other tested fungicides. These results provide important information to growers for the prevention and control of grey mould. [ABSTRACT FROM AUTHOR]

Simple Summary: The citrus red mite, Panonychus citri, is an important pest that causes serious citrus production losses in China. The insecticide fluazinam has a good control effect on the pest mites; however, its mechanism of action on mites remains unclear. In this study, we analyzed the transcriptomic sequencing and differential expression genes in P. citri treated with fluazinam, and identified some of the genes potential involved in detoxification metabolism related with the fluazinam exposure. Evaluating the efficacy of fluazinam, and analyzing the transcriptome data of P. citri under fluazinam stress, potentially provide a new agent for prevention and control of P. citri, and also preliminary research results for exploring the mechanism of action of fluazinam on P. citri. Given the up-regulated expression levels of genes for Mn-superoxide dismutase and catalase, we speculate that they play an important role in fluazinam-stress action on P. citri. The use of a large number of chemical acaricides to control these pest mites has led to an increasing problem of pesticide resistance, which has always been the difficulty in integrated pest management (IPM). Fluazinam has a good control effect on Panonychus citri, the serious pest on citrus; however, we only know the mechanism of action of fluazinam as a fungicide and its mechanism of action on mites remains unclear. Through analysis using Illumina high-throughput transcriptomic sequencing and differential expression genes in P. citri treated with fluazinam, 59 cytochrome P450 genes, 23 glutathione s-transferase genes, five carboxylate esterase genes, 11 superoxide dismutase genes and 15 catalase genes were identified. The Gene Ontology enrichment and the enrichment of KEGG results showed that the treatment were enrichment for redox enzyme pathways. Evaluating the efficacy of fluazinam, and analyzing the transcriptome data of P. citri under fluazinam stress, potentially provide a new agent for prevention and control of P. citri, and also preliminary research results for exploring the mechanism of action of fluazinam on P. citri. Given the up-regulated expression levels of genes for Mn-superoxide dismutase and catalase, we speculate that they play an important role in fluazinam-stress action on P. citri. [ABSTRACT FROM AUTHOR]

Cucumber target spot, caused by Corynespora cassiicola , is a devastating fungal disease in greenhouses in China. Lack of resistant cultivars and unscientific use of fungicides aggravated the difficulty to manage this disease. In recent years, resistance of C. cassiicola to benzimidazoles, quinone outside inhibitors, and succinate dehydrogenase inhibitors has occurred in China. Here, we tested the fluazinam sensitivity distribution of 79 C. cassiicola isolates from different provinces in China based on mycelial growth inhibition. The EC 50 values of fluazinam ranged from 0.1002 to 0.3129 µg/ml with a mean of 0.2136 ± 0.0495 µg/ml, and the sensitivity frequency was normally distributed ( P = 0.2083, Shapiro-Wilk test). Meanwhile, the EC 50 values for spore germination inhibition ranged from 0.0992 to 0.2278 µg/ml with a mean of 0.1499 ± 0.0504 µg/ml. This indicated that fluazinam exhibited an excellent in vitro fungicidal activity on both mycelial growth and spore germination. In addition, fluazinam also exhibited a good in planta control efficacy on detached cucumber leaves in the protective and curative assays. Moreover, the biological and physiological characteristics of C. cassiicola as affected by fluazinam were determined. Fluazinam not only significantly inhibited respiration and adenosine triphosphate production but also caused the increase of cell membrane permeability and the dysfunctions of cellular homeostasis. Interestingly, we found that fluazinam especially damaged vacuole structures, causing the redistribution of vacuole substances. Taken together, our findings provide not only essential references for resistance management of C. cassiicola but also interesting insights for further revealing the action mode of fluazinam against plant pathogens.

Fluazinam and dimethomorph 35% suspension concentrate (SC) is a new combined fungicide formulation introduced in China to improve fungicidal efficacy and decrease the risk of resistance in potatoes. Fluazinam and dimethomorph dissipation and residues in potatoes, potato plants, and soil under field conditions were determined by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Fluazinam and dimethomorph 35% SC was applied at two doses to potatoes and soil in Ningxia Autonomous Region and Anhui Province, China. Fluazinam and dimethomorph dissipation fitted first-order kinetics, and the fluazinam half-lives in potato plants and soil were 3.3-5.4 and 9.4-9.5 days, respectively. The dimethomorph half-lives in potato plants and soil were 2.1-2.6 and 5.9-8.6 days, respectively. Fluazinam and dimethomorph 35% SC was sprayed onto potato plants three or four times at application rates of 420 and 630 g a.i. ha -1 with 7 days between applications. Potato and soil samples were collected at 3, 7, and 14 days after the last application. Potatoes and soil had fluazinam concentrations of < 0.01 and < 0.05-0.183 mg kg -1 , respectively, and dimethomorph concentrations of < 0.01 and 0.129-0.677 mg kg -1 , respectively. The final fluazinam and dimethomorph concentrations in potatoes were below the EU maximum residue limits (0.02 and 0.05 mg kg -1 , respectively) 3 days after application. Fluazinam and dimethomorph can therefore be applied to potatoes at the recommended doses.