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In order to clarify the bioactivity of fluazinam to Fusarium pseudograminearum, the mycelial growth of 86 strains of F. pseudograminearum isolated from various cities in Henan Province from April to May 2022 was determined. The sensitivity baseline was established, and the field control efficacy of fluazinam on Fusarium crown rot (FCR) was determined. The results showed that the minimum inhibitory concentration of fluazinam on mycelial growth was 20 µg/mL, the effective concentration (EC50) of fluazinam on the mycelial growth of 86 strains was 0.013-0.492 µg/mL, and the average EC50 value was 0.194 µg/mL. The sensitivity of 57 strains (66.3%) was approximately normal distribution, and the average EC50 value of (0.201±0.057) µg/mL was used as the sensitivity baseline of F. pseudograminearum to fluazinam. The sensitivity of strains in the same city was quite different, and the ratio of the maximum and minimum EC50 value was 2.8-36.7. The difference in Luohe was the largest, and the difference in Xuchang was the smallest. There was no significant difference in the sensitivity of strains to fluazinam in different cities. There was no significant correlation between the sensitivity of F. pseudogramine to fluazinam and the geographical origin of the strains in Henan Province. There was no significant correlation between the sensitivity to fluazinam and its sensitivity to carbendazim and tebuconazole. Seed soaking with 500 g/L fluazinam suspension concentrate (SC), the incidence of FCR in Yichuan County and Xin'an County decreased by 45.46% and 56.88%, respectively, at the double ridge stage, and the white spike rate decreased by 8.73% and 13.67%, respectively, at the milky stage. The control efficacy of seed soaking with 500 g/L fluazinam SC against FCR of wheat at the double ridge stage was better, reaching more than 51% in both places. This study laid a theoretical basis for the prevention and control of fluazinam in FCR. [ABSTRACT FROM AUTHOR]

This study designed and synthesized a new drug-loading nanomaterial, the three-armed starshaped polymer compound (TaSPC), and loaded the broad-spectrum fungicide fluazinam to prepare TaSPC/fluazinam nanocarrier particles. The principle and drug-loading performance of TaSPC loading fluazinam were investigated by molecular docking simulation and ultraviolet spectrophotometry. The appearance and particle size changes before and after loading fluazinam onto TaSPC were compared and analyzed by transmission electron microscopy and scanning electron microscopy. The physicochemical properties of TaSPC and TaSPC/fluazinam were characterized by Zeta potential analysis, contact angle measurement with strawberry leaves, and uptake test with Rhodamine 6G. The in vitro and in vivo inhibitory effects of TaSPC/fluazinam on four plant pathogenic fungi, the toxicity of TaSPC to human umbilical vein endothelial cells, and the toxicity of TaSPC and TaSPC/fluazinam to Apis mellifera ligustica Spin, were determined. The results indicated that TaSPC could spontaneously combine with fluazinam through hydrophobic interaction, with a pesticide loading rate (PLC) of 9%. The particle size of TaSPC/fluazinam was 17.86 nm, which was significantly reduced by 71.4% compared to the original fluazinam (62.46 nm). After loading with TaSPC, the contact angle of the TaSPC/fluazinam droplet on strawberry leaves decreased from 44.08° to 33.60°, a significant reduction of 23.78%. The inhibitory effect of TaSPC/fluazinam on plant pathogenic fungi was significantly enhanced compared to the original fluazinam. Among them, the inhibitory activity against Botrytis cinerea was the highest, with an inhibition rate of 75% at a dose of 0.2 mg/L, an increase of nearly 60% compared to the original fluazinam. Within a reasonable application range, TaSPC had low cytotoxicity, and both TaSPC and TaSPC/fluazinam had low toxicity to pollinating bees. The study demonstrated that TaSPC is a significant benchmark for the development of efficient and low-toxicity nanocarrier materials and the reduction of pesticide use. [ABSTRACT FROM AUTHOR]

Fluazinam a promising fungicide, is not yet registered in India. Consequently it is important to study the dissipation of its specific formulation in Indian soil and water. This study focuses on the degradation and residue dynamics of Fluazinam (40% SC) in different soil types (alluvial, lateritic, coastal saline and black) and water pH (4.0, 7.0, 9.2). Adsorption kinetic models suggested that the half-life period (days) varies among soils following the order lateritic (Jhargram), 54.07 > alluvial (Mohanpur), 45.10 > coastal saline (Canning), 28.33 > black (Pune) 26.18. These differences are attributed to soil pH and organic carbon (OC) content, where higher pH levels reduce pesticide adsorption, leading to quicker dissipation, while higher organic carbon content provides more binding sites, slowing down the process. The first order kinetics explained the dissipation better compared to second order model across all soil types. The study also found that the half-life of was lowest at pH 9.2, as compared to pH 7.0, and very high stability at pH 4.0. Additionally, the study introduces an interactive R-based tool for analysing dissipation kinetics and half-life of different pesticides offering a valuable resource for researchers and stakeholders. [ABSTRACT FROM AUTHOR]

BACKGROUND: The use of pesticides in greenhouse vegetable cultivation is necessary and significant. However, traditional pesticide application methods such as the use of backpack sprayers with water‐diluted pesticides have certain drawbacks, e.g., uneven distribution, high labor intensity, and safety risks. RESULTS: In this work, fluazinam ultra‐low‐volume liquids (Flu‐ULVs) were prepared using oily solvents as carriers. The effects of different oils on the physical properties of the preparations were investigated. The Flu‐ULV can be sprayed directly using a hand‐held ultra‐low‐volume (ULV) sprayer without dilution with water. Compared with commercial water‐based suspension concentrates of fluazinam, the Flu‐ULV samples showed better wetting of tomato leaves, better atomization, and more uniform droplet distribution. At a dosage of 300 mL/ha, the coverage rate of tomato leaves ranged from 32.47% to 79.3%, with a droplet deposition density of 556 to 2017 droplets/cm2. Application of Flu‐ULVs provided 70.86% control efficacy against gray mold in tomatoes, which was higher than those achieved with reference products. Dermal exposure to Flu‐ULVs was also evaluated in greenhouse experiments. The coverage rates for all parts of the operator's body ranged from 0.02% to 0.07%, with deposition volumes of 2.23 to 12.26 μg/cm2. CONCLUSION: Ground ULV spraying of fluazinam was proved to be an effective and safe management option for the control of tomato gray mold in greenhouses. This study laid a foundation for the use of ultra‐low volume spray to control vegetable diseases in greenhouse, especially those induced by high humidity environment. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Stingless bees (Hymenoptera: Meliponini) are pollinators of both cultivated and wild crop plants in the Neotropical region. However, they are susceptible to pesticide exposure during foraging activities. The fungicide fluazinam is commonly applied in bean and sunflower cultivation during the flowering period, posing a potential risk to the stingless bee Partamona helleri, which serves as a pollinator for these crops. In this study, we investigated the impact of acute oral exposure (24 h) fluazinam on the survival, morphology and cell death signaling pathways in the midgut, oxidative stress and behavior of P. helleri worker bees. Worker bees were exposed for 24 h to fluazinam (field concentrations 0.5, 1.5 and 2.5 mg a.i. mL−1), diluted in 50 % honey aqueous solution. After oral exposure, fluazinam did not harm the survival of worker bees. However, sublethal effects were revealed using the highest concentration of fluazinam (2.5 mg a.i. mL−1), particularly a reduction in food consumption, damage in the midgut epithelium, characterized by degeneration of the brush border, an increase in the number and size of cytoplasm vacuoles, condensation of nuclear chromatin, and an increase in the release of cell fragments into the gut lumen. Bees exposed to fluazinam exhibited an increase in cells undergoing autophagy and apoptosis, indicating cell death in the midgut epithelium. Furthermore, the fungicide induced oxidative stress as evidenced by an increase in total antioxidant and catalase enzyme activities, along with a decrease in glutathione S-transferase activity. And finally, fluazinam altered the walking behavior of bees, which could potentially impede their foraging activities. In conclusion, our findings indicate that fluazinam at field concentrations is not lethal for workers P. helleri. Nevertheless, it has side effects on midgut integrity, oxidative stress and worker bee behavior, pointing to potential risks for this pollinator.

Fluazinam a promising fungicide, is not yet registered in India. Consequently it is important to study the dissipation of its specific formulation in Indian soil and water. This study focuses on the degradation and residue dynamics of Fluazinam (40% SC) in different soil types (alluvial, lateritic, coastal saline and black) and water pH (4.0, 7.0, 9.2). Adsorption kinetic models suggested that the half-life period (days) varies among soils following the order lateritic (Jhargram), 54.07 > alluvial (Mohanpur), 45.10 > coastal saline (Canning), 28.33 > black (Pune) 26.18. These differences are attributed to soil pH and organic carbon (OC) content, where higher pH levels reduce pesticide adsorption, leading to quicker dissipation, while higher organic carbon content provides more binding sites, slowing down the process. The first order kinetics explained the dissipation better compared to second order model across all soil types. The study also found that the half-life of was lowest at pH 9.2, as compared to pH 7.0, and very high stability at pH 4.0. Additionally, the study introduces an interactive R-based tool for analysing dissipation kinetics and half-life of different pesticides offering a valuable resource for researchers and stakeholders.

Fusarium head blight (FHB), predominately caused by ascomycete Fusarium graminearum sensu stricto, is a devastating fungal disease of cereal crops worldwide. In this study, baseline sensitivity of F. graminearum s. str. to fluazinam was established using 100 isolates that were collected from Anhui and Jiangsu provinces of China in 2009 and 2018. The EC50 values of fluazinam on mycelial growth inhibition ranged from 0.0211 to 0.1097 μg/mL and the mean EC50 was 0.0601 ± 0.0191 μg/mL, which indicated that fluazinam had a strong inhibitory effect on mycelial growth of F. graminearum s. str. To acquire fluazinam‐resistant (FluR) mutants, one wild‐type strain (PH‐1, with assembled genome) and another four fluazinam‐sensitive (FluS) isolates randomly selected from the above‐mentioned population were domesticated with fluazinam or mutagenized by ultraviolet light in vitro. As a result, 45 FluR mutants were obtained with resistance frequencies of 0.68% (domestication) and 8 in 10−8 (mutagenesis), respectively. Of the 45 FluR mutants, 11 were selected to determine the biological fitness. Based on data of radial mycelial growth, asexual and sexual reproduction, response to environmental stresses, pathogenicity and deoxynivalenol production, all the tested mutants suffered from a fitness penalty. Additionally, slightly positive cross‐resistance was observed between the combination of fluazinam and tebuconazole, pyraclostrobin, or pydiflumetofen, but not phenamacril or carbendazim. Therefore, a low‐to‐moderate risk of development of F. graminearum s. str. resistant to fluazinam was suggested, indicating that fluazinam could be a good alternative fungicide against the FHB in the field. [ABSTRACT FROM AUTHOR]

Since the mid‐2010s, Phytophthora infestans clones that have been dominant in Western Europe from the beginning of the 21st century, for example, EU_13_A2, EU_6_A1 and EU_1_A1, are being replaced by several other emerging clones, including EU_37_A2. The objective of this study was to determine whether the main drivers for the success of EU_37_A2 in Western Europe are associated with decreased fungicide sensitivity, increased virulence and/or aggressiveness. Axenic P. infestans cultures were sampled in the 2016 and 2017 growing seasons from potato crops in France and the United Kingdom. Amongst these, four genotypes were identified: EU_37_A2, EU_13_A2, EU_1_A1 and EU_6_A1. Although a wide range of fluazinam sensitivity was found amongst individual isolates, clonal lines EU_13_A2 and EU_37_A2 showed decreased sensitivity to fluazinam. EU_37_A2 overcame the R5 differential cultivar more often than isolates of EU_1_A1 or EU_6_A1. However, this does not explain the competitive advantage of EU_37_A2 over the virulent EU_13_A2. The fittest genotype, as measured by aggressiveness under controlled conditions, was EU_6_A1, followed by EU_37_A2, EU_13_A2 and then EU_1_A1. EU_37_A2 isolates also showed a shorter latent period than either EU_6_A1 or EU_13_A2, which could favour its long‐term persistence. Overall, the data suggest that the emergence of EU_37_A2 in Western Europe was driven by its resistance to a then‐major fungicide and shorter generation time. This conclusion is further supported by the fact that EU_37_A2 emergence was slowed by the progressive reduction in the use of fluazinam as a single active ingredient in the years following its initial detection. [ABSTRACT FROM AUTHOR]

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]

The soilborne pathogen Spongospora subterranea f. sp., which is subterranean and responsible for powdery scab, poses a serious threat to potato production in China. Single applications of fluazinam, cyazofamid and bupirimate via furrow application or seed dressing during the sowing period and combined application with root irrigation during the tuber initiation stage were assessed for their ability to control powdery scab under field conditions. Three field trials revealed that fluazinam or cyazofamid furrow application at 1500 g a.i. ha−1 during the sowing period combined with root irrigation at 1500 g a.i. ha−1 during the tuber initiation stage significantly reduced the disease incidence and disease index of potato powdery scab, with good control efficacy (58.1–79.4% and 53.1–78.5%, respectively), and provided high potato yields (3.37–5.08 kg m−2 and 3.26–4.88 kg m−2, respectively) and gross revenue for growers. However, due to the low price of potato and high control cost, the two selected promising chemical treatments have few advantages in terms of economic benefits. Overall, considering their control efficacy and economic benefits, fluazinam or cyazofamid furrow application combined with root irrigation treatment could be recommended for integrated powdery scab management, especially for high-value seed potato production in China. • Fluazinam, cyazofamid and bupirimate were selected for controlling powdery scab. • Single application by furrow application or seed dressing during sowing period were assessed. • Combined application with root irrigation during tuber initiation stage were assessed. • Fluazinam or cyazofamid furrow application and root irrigation was recommended for controlling powdery scab. [ABSTRACT FROM AUTHOR]

Stingless bees (Hymenoptera: Meliponini) are pollinators of both cultivated and wild crop plants in the Neotropical region. However, they are susceptible to pesticide exposure during foraging activities. The fungicide fluazinam is commonly applied in bean and sunflower cultivation during the flowering period, posing a potential risk to the stingless bee Partamona helleri , which serves as a pollinator for these crops. In this study, we investigated the impact of acute oral exposure (24 h) fluazinam on the survival, morphology and cell death signaling pathways in the midgut, oxidative stress and behavior of P. helleri worker bees. Worker bees were exposed for 24 h to fluazinam (field concentrations 0.5, 1.5 and 2.5 mg a.i. mL−1), diluted in 50 % honey aqueous solution. After oral exposure, fluazinam did not harm the survival of worker bees. However, sublethal effects were revealed using the highest concentration of fluazinam (2.5 mg a.i. mL−1), particularly a reduction in food consumption, damage in the midgut epithelium, characterized by degeneration of the brush border, an increase in the number and size of cytoplasm vacuoles, condensation of nuclear chromatin, and an increase in the release of cell fragments into the gut lumen. Bees exposed to fluazinam exhibited an increase in cells undergoing autophagy and apoptosis, indicating cell death in the midgut epithelium. Furthermore, the fungicide induced oxidative stress as evidenced by an increase in total antioxidant and catalase enzyme activities, along with a decrease in glutathione S-transferase activity. And finally, fluazinam altered the walking behavior of bees, which could potentially impede their foraging activities. In conclusion, our findings indicate that fluazinam at field concentrations is not lethal for workers P. helleri. Nevertheless, it has side effects on midgut integrity, oxidative stress and worker bee behavior, pointing to potential risks for this pollinator. [Display omitted] • The concentration of fluazinam recommended by the manufacturer does not kill Partamona helleri after 24 hours of exposure. • Fluazinam reduces the food consumption of the stingless bee. • Ingestion of fluazinam causes histopathological changes in the stingless bee midgut. • Fluazinam induces oxidative stress and alters the behavior of Partamona helleri. • Fluazinam may affect crop pollination by stingless bees. [ABSTRACT FROM AUTHOR]

Fungicides are used to control pathogenic fungi of crop species, but they have also been shown to alter behavioral, life history and fitness related traits of nontarget insects. Here, we tested the fungicide effects on feeding behavior, survival and physiology of the nontarget pest insect, the Colorado potato beetle (CPB) (Leptinotarsa decemlineata). Feeding behavior was studied by a choice test of adult beetles, which were allowed to choose between a control and a fungicide (fluazinam) treated potato leaf. Larval survival was recorded after 24 and 72 h exposure to control and fungicide‐treated leaves with 2 different concentrations. The adults did not show fungicide avoidance behavior. Similarly, survival of the larvae was not affected by the exposure to fungicides. Finally, to understand the effects of fungicides at the physiological level (gene expression), we tested whether the larval exposure to fungicide alter the expression of 5 metabolic pathway and stress associated genes. Highest concentration and 72‐h exposure caused upregulation of 1 cytochrome P450 (CYP9Z14v2) and 1 insecticide resistance gene (Ldace1), whereas metabolic detoxification gene (Ugt1) was downregulated. At 24‐h exposure, highest concentration caused downregulation of another common detoxification gene (Gs), while both exposure times to lowest concentration caused upregulation of the Hsp70 stress tolerance gene. Despite these overall effects, there was a considerable amount of variation among different families in the gene expression levels. Even though the behavioral effects of the fungicide treatments were minor, the expression level differences of the studied genes indicate changes on the metabolic detoxifications and stress‐related pathways. [ABSTRACT FROM AUTHOR]

Wolrdwide, late blight disease initiated by Phytophthora infestans cause major yield loss in potatoes. Management depends mainly on the application of chemical fungicides that might cause environmental pollution. Therefore, current study aimed to investigate the fungicidal activity of biotic (BioArc) and abiotic (Fluazinam and Potasin F) compounds individually or sequentially against P. infestans in two field seasons. The results showed that disease severity was significantly decreased in all treated plants compared to control potatoes. In addition, all treatments caused increment of vegetative growth, tuber yield, and tuber contents of N, P, K, reducing, non-reducing, total sugar, protein, starch, total carbohydrate, TSS, and Vit C. In conclusion, combination of Fluazinam, BioArc, and Potasin F as tri-sequential treatment would be an appropriate alternative to chemical fungicides in the management of P. infestans on potato vegetative growth and improve yield production. [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]

Main conclusion: Botrytis cinerea and fungicides interacted and influenced selected biochemical compounds. DPPH and glutathione are the first line of defence against biotic/abiotic stress. Plant metabolites are correlated with fungicides level during dissipation. Botrytis cinerea is an etiological agent of gray mould in leafy vegetables and is combated by fungicides. Fluazinam and azoxystrobin are commonly used fungicides, which inhibit oxidative phosphorylation in fungi. In this study, lettuce was (i) inoculated with B. cinerea; (ii) sprayed with azoxystrobin or fluazinam; (iii) inoculated with B. cinerea and sprayed with fungicides. This investigation confirmed that B. cinerea and fungicides affected lettuce’s biochemistry and stress status. B. cinerea influenced the behaviour of fungicides reflected by shortened dissipation of azoxystrobin compared to non-inoculated plants, while prolonged degradation of fluazinam. Stress caused by B. cinerea combined with fungicides reduced level of chlorophylls (53.46%) and carotenoids (75.42%), whereas increased phenolic compounds (81%), ascorbate concentrations (32.4%), and catalase activity (116.1%). Abiotic stress caused by fungicides contributed most to the induction of carotenoids (107.68 µg g−1 on dissipation day 3−1). Diphenyl picrylhydrazyl (DPPH) radical scavenging activity and glutathione concentration peaked from the first hour of fungicides dissipation. For the first time correlation between the status of plant metabolites and fungicides during their dissipation was observed. These results indicate that non-enzymatic antioxidants could be the first-line compounds against stress factors, whereas ascorbate and antioxidant enzymes tend to mitigate stress only secondarily. The findings of this study help better understand plant biochemistry under biotic/abiotic stress conditions. [ABSTRACT FROM AUTHOR]

To screen the effective fungicides inhibiting tobacco bacterial wilt, streptomycin was used as the control agent, and the sensitivities of Ralstonia solanacearum to fungicides fluazinam, SYP-14288, benziothiazolinone and kasugamycin were determined by Bioscreen C growth curve tester. The synergistic interactions between fluazinam and nano sulfur, nano copper, nano silver at nine combination ratios were tested respectively by the Wadley method. The results showed that the average EC50 values of SYP-14288 and fluazinam against R. solanacearum were 0.037 8 and 0.305 0 μg/mL, the distribution ranges of EC50 were 0.018 7-0.053 4 μg/mL and 0.147 1-0.890 4 μg/mL respectively. The average EC50 values of streptomycin, benziothiazolinone and kasugamycin against R. solanacearum were 0.546 3, 2.429 9 and 9.927 3 μg/mL, indicating that fluazinam and SYP-14288 could effectively inhibit the growth of R. solanacearum, and their control effects were better than that of streptomycin. The sensitivity baselines of R. solanacearum to the five fungicides all obeyed normal distribution with continuous single peak curves, which could be used for monitoring the strains resistant to R. solanacearum in tobacco fields. The EC50 of the combined fluazinam and nano fungicides at different ratios were all lower than that of single nano fungicide. The combination of fluazinam and nano sulfur at a volume ratio of 1:40 had a synergistic coefficient of 1.60. The additive effect was the most obvious when fluazinam and nano copper were mixed at the ratio of 80:1(EC50=0.142 2 μ g/mL). There was an additive effect by mixing fluazinam and nano silver at 1:20, and the synergistic coefficient was 1.41. [ABSTRACT FROM AUTHOR]

Among 6 fungicides, fluazinam, which had an excellent inhibitory effect on mycelial growth and spore germination, was also effective in controlling jujube anthracnose in the field. While EC50 values of metconazole and tebuconazole ranged from 0.2 to 0.9 μg/ml and from 0.4 to 1.1 μg/ml against the mycelial growth, respectively, each inhibitory effect on spore germination was low by 7.4% and 11.1% at 50.0 μg/ml. In the field test, they showed the control value of 80.5% and 77.0%, respectively. The protective fungicides, as mancozeb and folpet, which had a low inhibitory effect on the mycelial growth, but had a high inhibitory effect of spore germination, showed excellent disease control activities by 87.6% and 92.0% in the field. Showing a result of resistance monitoring conducted with the isolates of Colletotricum gloeosporioides, the resistance against carbendazim was already generated in the field, but it was thought that there was no resistance to pyraclostrobin, fluazinam and tebuconazole. However, if the resistance factor value of the population of C. gloeosporioides isolates to pyraclostrobin was high by 160.4, the diversity of the response to the fungicide in the population was high, so it should be taken more attention to the resistance management.

In Brazil, Sclerotinia stem rot (SSR) control in soybean depends primarily on application of the fungicides carbendazim, fluazinam, and procymidone. While these fungicides can provide effective control of the disease, their protection period, which is crucial for timing their optimal application, is poorly understood. In the present study, the protection period of carbendazim, fluazinam and procymidone was determined using a detached leaf bioassay (DLB) and chromatography. For the DLB, soybean plants were treated twice with each fungicide with or without mineral oil as adjuvant; leaves were collected at two or three-day intervals from 11 to 23 days, inoculated with Sclerotinia sclerotiorum mycelium, and the necrotic area was assessed 48 h after inoculation. For the chromatography test, each fungicide was applied and the leaves were collected every two days after treatment for 14 days. Fungicide residue concentration in tissue was determined according to a modified version of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method. At 5, 7, and 9 days after the first application, fluazinam, carbendazim and procymidone, respectively, had no protective effect even when applied with mineral oil. Greater control efficacy was achieved after a second application. Fluazinam showed protective activity up to 4 days while carbendazim and procymidone showed about 10 days. The mineral oil only enhanced protection activity of procymidone in the second application. The analytical chemical separation indicated that the relative concentration of fluazinam decreased at a faster rate than that of carbendazim and procymidone. At day 14, the concentration of carbendazim and procymidone decreased from 34.97 to 9.39 mg kg−1, and 58.98 to 11.22 mg kg−1, respectively, suggesting that 10–14 days represent the approximate timing in spacing two consecutive applications. The knowledge of the protection period of these fungicides sets the basis to improving their timing of applications. [ABSTRACT FROM AUTHOR]

To study the dissipation rate and the final residue level of fluazinam in wax gourd, the dissipation dynamics and final residue trials of 500 g/L SC were carried out in Beijing, Shandong, Anhui, Hunan, Yunnan and Guangdong Provinces. Among them, dissipation dynamic trials were set up in Beijing and Anhui. Samples were extracted with acetonitrile, cleaned up by primary secondary amine (PSA), detected by ultra performance liquid chromatography-tandem mass spectrometry(UPLCMS/MS), and quantified by external standard method. The results showed that, among the spiked levels of 0.01-1 mg/kg, the recoveries ranged from 89% to 109%, the relative standard deviations (RSDs) ranged from 2.8% to 12%, and the limit of quantification (LOQ) was 0.01 mg/kg. The half-lives of fluazinam on wax gourd were between 2.04 to 2.17 days in Beijing and Anhui, respectively. The final residue trials in six provinces showed that the residue level of fluazinam on wax gourd was between

A total of 40 Colletotrichum strains causing anthracnose on Polygonatum kingianum were isolated and identified by morphology and ITS sequence in 2019. They were collected from three producing regions in Yunnan Province. Their sensitivities to fluazinam, prochloraz and difenoconazole were tested using the mycelium growth rate method. The results showed that all the 40 strains isolated from P. kingianum diseased leaves might belong to genus of Colletotrichum, i.c. C. gloeosporioides, C. fructicola, C. boninense and C. acutatum. Among them, 29 strains belong to C. fructicola, accounting for 72.5% of the total isolated strains. Fungicide sensitivity tests indicated that fluazinam, prochloraz and difenoconazole showed strong antifungal activities against the growth of all the tested strains. The EC50 values of fluazinam, prochloraz and difenoconazole to all tested strains were in the range of 0.028-0.53 mg/L, 0.018-2.69 mg/L and 0.158-2.57 mg/L, respectively. The sensitivities of all strains to fluazinam were higher than those to prochloraz and difenoconazole. No resistant strains to fluazinam, prochloraz and difenoconazole were found in those three producing regions of Yunnan Province. [ABSTRACT FROM AUTHOR]

A new nano host-fungicide, namely zinc hydroxide nitrate–sodium dodecyl sulphate–fluazinam (ZHN–SDS–FZ) was successfully synthesised using an ion exchange method. The intercalation of fluazinam (FZ) in the interlayer gallery of ZHN–SDS was confirmed by PXRD pattern with the basal spacing of 32.7 Å. The FTIR confirmed that FZ exist in the interlayer gallery. The elemental analysis also supported the presence of FZ in the interlayer ZHN–SDS where the percentages of nitrogen, which contributed by FZ was 65.6%. Meanwhile, the percentages of Zn in the nano host-fungicides was estimated to be 11.5%. Furthermore, TGA/DTG pattern showed that the nano host-fungicide ZHN–SDS–FZ has better thermal stability compared to pure FZ. The intercalation of FZ leads to the change of morphology, surface area and also the porosity. The classification of porosity of ZHN–SDS is mesoporous, meanwhile ZHN–SDS–FZ is non-porous. The BET-BJH surface area shows that ZHN–SDS and ZHN–SDS–FZ is of Type IV and Type III respectively. The controlled release of FZ from the ZHN–SDS–FZ nano host showed that phosphate and carbonate solutions yield the higher percentages of release compared to chloride solutions. The controlled release of FZ was found to be governed by a pseudo-second order mechanism for all medium. In this research, FZ can act as a good guest anion to be intercalated in the interlayer ZHN–SDS to be further used in agricultural sector due to the slowest release of FZ in the phosphate, carbonate and chloride solutions as a release medium. [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]

In this contribution, polyvinyl pyrrolidone capped copper nanoclusters (PVP‐Cu NCs) were synthesised through a one‐pot route possessing the advantages of rapidness and environmental friendliness. Also, the optical characteristics of the as‐prepared Cu NCs were characterised using fluorescence spectroscopy, UV–vis absorption spectroscopy. The structure and composition were studied through Fourier transform infrared, transmission electron microscopy, X‐ray photoelectron spectroscopy. It exhibited good water solubility, excellent photo stability, and resistance to sodium chloride. The Cu NCs revealed blue fluorescence and displayed excitation‐dependent fluorescence characteristics. More importantly, the fluorescence intensity of PVP‐Cu NCs was linearly quenched in the range of 5–80 μM (concentrations of fluazinam) and the detection limit was 0.98 μM. Finally, the fluorescence sensor was successfully employed to detect fluazinam in natural water samples. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science 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.)

In this contribution, a one-pot synthesis method possessing the advantages of simple, green and low-cost had been researched for the preparation of L-histidine-stabilized Cu nanoclusters (Cu NCs). Subsequently, the structure and optical properties of as-prepared Cu NCs were studied by using Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy and UV-Vis absorption spectroscopy. TEM image of the Cu NCs showed high dispersion with an average diameter of 2.0 nm. Fluorescence spectrum displayed that the Cu NCs emitted green fluorescence (emission wavelength of 492 nm) under excitation wavelength of 393 nm. Moreover, the as-synthesized Cu NCs illustrated excellent performances, such as good water solubility, UV stability and high-salt resistance. Interestingly, the fluorescence intensity of as-prepared Cu NCs was obviously quenched in the presence of fluazinam. Under optimal conditions, the relative fluorescence intensity was linear with the fluazinam concentrations from 1 to 40 μ M, with a detection limit of 0.25 μ M. Eventually, the fluorescence sensor was successfully used to determine fluazinam in real water samples. A simple, sensitive, and selective method based on the fluorescence quenching of L-histidine stabilized copper nanoclusters for rapid determination of fluazinam was developed. [ABSTRACT FROM AUTHOR]

In this study, direct detection of fluazinam was realized using a fluorescent sensor using disulfide quantum dots (MoS 2 QDs) via inner filter effect (IFE). The maximum excitation of as-prepared MoS 2 QDs presented a complementary spectral-overlap with the maximum absorption of fluazinam. Thus the occurrence of inner filter effect led to the significant fluorescence quenching of MoS 2 QDs. Additionally, fluorescent quenching efficiency of MoS 2 QDs could be enhanced by the effects of π-π stacking, hydrogen bond and electrostatic interaction between fluazinam and MoS 2 QDs, and these non-chemical bond responses also promoted the selectivity for fluazinam detection. Under the optimum conditions, the IFE-based fluorescent sensor exhibited a relative wide linear range from 50 nM to 25 μM with the LOD of 2.53 nM (S/N = 3). In addition, a paper-based sensor was established by cross-linking the MoS 2 QDs into cellulose membrane for naked-eyed detection and digital analysis of fluazinam. The paper-based sensor presented a liner range from 10 μM to 800 μM for fluazinam detection with the LOD of 2.26 μM. Additionally, the acceptable recoveries were obtained for fluazinam detection in the spiked samples of tomato, potato and cucumber, indicating that the proposed method provided an effective sensing platform for real applications of fluazinam detection in food safety. Image 1 • MoS 2 QDs were introduced as fluorescent readout for measurement of fluazinam. • A paper-based sensor was developed using MoS 2 QDs for fluazinam detection. • Nake-eyed and digital readout were realized by an IISV system. • This strategy presented a model to develop fluorescence sensors based on IFE. [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]

• Two new zn (II) coordination polymers were synthesized and characterized. • Complex 1 and complex 2 can detect 2,4,6-Trinitrophenol (TNP), tetracycline (TET) and fluazinam (FLU) with a high sensitivity and selectivity. • Coordination polymers have shown great potential in clinical diagnosis and treatment. Two new Zn(II) coordination polymers, namely, {[Zn 2 (L)(4,4′-bip) 2 ] ·4H 2 O} n (1) {[Zn (H 2 L) (1,2-die)] · H 2 O} n (2) [H 4 L = 5, 5′-(ethane-1, 2-diyl) diisophthalic acid, 4, 4′-bip = 4, 4′ - bis (1-imidazolyl) biphenyl , 1, 2-die = 1,2-di(pyridin-4-yl)ethene] have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, IR spectra and fluorescent analysis. Coordination polymers 1 and 2 are 2D network structures. They both have 3D supramolecular structures based on the interspersion of 2D networks. They can detect 2, 4, 6-trinitrophenol (TNP), tetracycline (TET) and fluazinam (FLU) by fluorescence quenching. And the possible reasons for the quenching of TNP, TET, and FLU were discussed in detail, which may be energy resonance transfer. These new zinc coordination polymers could be used multifunctional sensors on NACs, antibiotics and pesticides in the future. In addition, the results of fluorescence sensing experiments show that Zn(II) coordination polymers composed of different auxiliary N donors have significant influence on the detection limits. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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.)

Pesticides are biological or chemical substances used to manage pests and diseases. Encapsulation of pesticides in biodegradable carriers creates a slow-release system that can improve water dispersibility and prolong residual activity. We prepared two kinds of poly (lactic-co-glycolic acid)(PLGA) nanoparticles (NPs) with polyvinyl alcohol (PVA) and sodium dodecyl sulfate (SDS) surfactants. These were used to encapsulate the fungicide fluazinam (Flu) against Rhizoctonia solani using the Shirasu Porous Glass (SPG) membrane emulsification method. Both nanoparticles had uniform spherical shapes with average diameters of 314.13 nm (SDS) and 612.80 nm (PVA). The slow-release microspheres had excellent sustained-release properties, resistance to UV degradation, storage stability, leaf surface coverage and antifungal efficacy compared to the commercial formulation. [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]

One of the economically important diseases of lettuce is lettuce big‐vein disease (LBVD), which leads to severe yield losses. LBVD is associated with a complex of two viruses, Lettuce big‐vein associated virus (LBVaV) and Mirafiori lettuce big‐vein virus (MLBVV). These viruses are transmitted by motile zoospores of Olpidium spp. fungi, which persist in the soil for decades through resting spores. In greenhouse and field experiments, this study tested whether changing plant and soil temperatures together with fungicide application would have a significant effect on controlling LBVD in lettuce. Soil fumigation with metam sodium was not effective at controlling the disease, as opposed to treatment with chloropicrin and methyl bromide. Moreover, the fungicides carbendazim and fluazinam were effective in reducing the incidence of Olpidium virulentus. Nevertheless, control of the fungal vector did not seem to be sufficient to control the disease due to the transition ability of the virus under low vector abundance. Crop covers, which affect the favourable environmental conditions for the viruses by lowering soil temperature and raising air temperature, reduced the disease symptoms. Combining fungicides with crop cover had a synergistic effect on reducing disease symptoms, thus providing a sustainable solution for LBVD. [ABSTRACT FROM AUTHOR]

Abstract Sclerotinia sclerotiorum is a necrotrophic and filamentous fungus with a broad host range. Fluazinam is a pyridinamine fungicide with a broad spectrum of antifungal activity and had a strong inhibition effect on mycelial growth of S. sclerotiorum populations. But the impact of fluazinam on morphological and physiological characteristics of S. sclerotiorum is little known. In this study, the EC 50 values of fluazinam to three strains of S. sclerotiorum (CZ17S, YZ55S and SA42S) were 0.0084, 0.007, 0.0065 μg/ml respectively. After fluazinam treatment, hyphae of S. sclerotiorum became thinner, hyphal offshoot of top increased, the distance between one septum and another became shorter, cell membrane permeability increased markedly, exopolysaccharide (EPS) content and oxalic acid content decreased significantly, peroxidase (POD) activity increased significantly and mycelial respiration was inhibited. While the number and dry weight of sclerotia, glycerol content in the mycelia did not significantly change. In protective activity assay on detached rapeseed leaves, application of fluazinam at 40 μg/ml and 80 μg/ml, the control efficacy reached to 41.4% and 100%, respectively. In curative activity assay, application of fluazinam at 100 μg/ml, the control efficacy reached to 61.09%. In the same concentration, protective activity of fluazinam against S. sclerotiorum was higher than curative activity. These results will contribute to us on evaluating the potential of the fungicide fluazinam for management of Sclerotinia stem rot and understanding the mode of action of fluazinam against S. sclerotiorum. Graphical abstract Unlabelled Image Highlights • Determined the effect of fluazinam on morphology of S. sclerotiorum • Investigated the impact of fluazinam on physiology of S. sclerotiorum • Analyzed the protective and curative activity of fluazinam against S. sclerotiorum [ABSTRACT FROM AUTHOR]

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a devastating disease in Henan Province, of the main rapeseed production areas in China. Fluazinam belongs to the broad‐spectrum phenylpyridinamine fungicides, which have high activity in inhibiting the mycelial growth of S. sclerotiorum. In this study, 191 field isolates were obtained from different oilseed rape fields in Henan Province, before being exposed to fluazinam in 2015. The baseline sensitivity of S. sclerotiorum to fluazinam was established. The effective concentration for 50% inhibition of mycelial growth (EC50) ranged from 0.0019 to 0.0337 μg/ml, and the mean EC50 value was 0.0084 ± 0.0055 μg/ml. The range of the frequency distribution was narrow. The results of a cross‐resistance assay revealed no cross‐resistance between fluazinam and carbendazim, dimethachlone, boscalid or fludioxonil. Field efficacy tests showed that the control efficacies of fluazinam (50% WG) applied at 150, 225 and 300 g ai ha−1 were 67%, 73% and 88%, respectively. In contrast, the control efficacies of boscalid (50% WG) and carbendazim (50% WP) applied at 225 and 1,500 g ai ha−1 were 71% and 52%, respectively. [ABSTRACT FROM AUTHOR]

The popular fungicide fluazinam is known to exhibit an unusual cyclic pattern of the protonophoric uncoupling activity in isolated rat liver mitochondria (RLM), with membrane deenergization followed by spontaneous recoupling in the minute scale, which is associated with glutathione conjugation of fluazinam catalyzed by glutathione-S-transferase (GST). Here, we compare the fluazinam effect on RLM with that on rat kidney (RKM) and heart (RHM) mitochondria by monitoring three bioenergetic parameters: oxygen consumption rate, mitochondrial membrane potential and reduction of nucleotides. Only in RLM, the uncoupling activity of fluazinam was transient, i.e. disappeared in a few minutes, whereas in RKM and RHM it was stable in this time scale. We attribute this difference to the increased activity of mitochondrial GST in liver. We report data on the detection of glutathione-fluazinam conjugates by mass-spectrometry, thin layer chromatography and capillary electrophoresis after incubation of fluazinam with RLM but not with RKM, which supports the assumption of the tissue specificity of the conjugation. [Display omitted] • Fluazinam exerts spontaneously reversible uncoupling of rat liver mitochondria (RLM). • By contrast, the uncoupling is not transient in rat kidney and rat heart mitochondria. • Glutathionylation of fluazinam is assumed to abrogate its uncoupling activity in RLM. • Glutathione-fluazinam conjugates are found by LC-MS and TLC after incubation with RLM. • Fluazinam appears to be a tissue-specific uncoupler in mammalian mitochondria. [ABSTRACT FROM AUTHOR]

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.

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. [ABSTRACT FROM AUTHOR]

Abstract Fusarium fujikuroi is the primary causal agent of rice bakanae disease. Fluazinam is a protective dinitroaniline fungicide which could interrupt the fungal cell's energy production. Little is known about the effects of fluazinam on F. fujikuroi. In this study, baseline sensitivity of F. fujikuroi to fluazinam was determined using 103 isolates collected from diseased young rice of different fields in Shaoxing of Zhejiang Province and Huaian of Jiangsu Province of China in 2016. The EC 50 values of fluazinam on inhibiting mycelial growth against 103 isolates of F. fujikuroi ranged from 0.0621 to 0.5446 μg/mL with the average value of 0.2038 ± 0.0099 μg/mL (mean ± standard error). The EC 50 values of fluazinam on suppressing conidium germination against 103 isolates of F. fujikuroi ranged from 0.1006 to 0.9763 μg/mL with the mean value of 0.3552 ± 0.0181 μg/mL. Treated with fluazinam, hyphae of F. fujikuroi were contorted, offshoot of top mycelia increased, conidial production descreased significantly and exopolysaccharide (EPS) content did not change significantly while peroxidase (POD) activity significantly decreased. Meanwhile, cell membrane permeability increased after treated with fluazinam. The analysis of cell ultrastructure indicated that fluazinam could damage the membrane structure of F. fujikuroi and cause a large number of vacuoles formed. In addition, fluazinam did not affect germination rate, plant height and fresh weight of rice, which indicated that fluazinam was safe to rice. All the results indicated that fluazinam had strong antifungal activity against F. fujikuroi and a potential application in controlling rice bakanae disease. These results will provide useful information for management of rice bakanae disease caused by F. fujikuroi and further increase our understanding about the mode of action of fluazinam against F. fujikuroi and other phytopathogens. Graphical abstract Unlabelled Image Highlights • Determined baseline sensitivity of Fusarium fujikuroi to fluazinam • Analyzed the effects of fluazinam on physiology of Fusarium fujikuroi • Tested the security of fluazinam to rice [ABSTRACT FROM AUTHOR]

Fluazinam is a dinitroaniline fungicide with broad-spectrum activities. However, the activity of fluazinam against Bipolaris maydis which is the causal agent of southern corn leaf blight is unknown yet. In this study, baseline sensitivity of B. maydis to fluazinam was determined using 92 isolates collected during 2015 and 2016 from different geographical regions in Jiangsu Province of China, and the EC 50 values ranged from 0.0396 to 0.9808 μg/ml with average value of 0.3853 ± 0.2297 μg/ml, and 0.079 to 0.7832 μg/ml with average value of 0.3065 ± 0.1384 μg/ml for mycelial growth and conidium germination respectively. Fluazinam did not affect the distribution of cell nucleus and the formation of septum of B. maydis . However, fluazinam could make mycelium of B. maydis contorted and the mycelial branches increased and inhibit the development of conidia. The result of transmission electron microscope showed that fluazinam damaged cell wall and cell membrane of mycelium, and make organelles in mycelial cell dissolved and vacuolated, and the cell almost broke up, which caused the intracellular plasma leakage increase. The protective activity test of fluazinam suggested that fluazinam had great control efficiency against B. maydis on detached corn leaves. Application of fluazinam at 10 μg/ml and 20 μg/ml, the control efficacy reached to 87.70% and 98.25% respectively. However, fluazinam had no curative activity against B. maydis on detached corn leaves. These results will contribute to us on evaluating the potential of the dinitroaniline fungicide fluazinam for management of diseases caused by B. maydis and understanding the mode of action of fluazinam against B. maydis . [ABSTRACT FROM AUTHOR]

SYP-14288 is a novel fungicide developed by the Shenyang Research Institute of Chemical Industry in China. Although preliminary studies indicate that SYP-14288 is highly effective against 32 important plant pathogens belonging to a range of taxonomic groups, its mode of action remains unknown. In this study, we documented that SYP-14288 has excellent activity against all of the asexual life stages of the plant-pathogenic oomycete Phytophthora capsici , and is especially effective in blocking cyst germination and other life stages that require high energy consumption. In assays designed to determine the fungicide's mode of action, addition of ATP reduced SYP-14288 inhibition of P. capsici , which suggested that SYP-14288 inhibits ATP synthesis of the pathogen. This inference was confirmed in that treatment with SYP-14288 sharply reduced the ATP content in P. capsici . The respiration rate of P. capsici was positively correlated with the concentration of SYP-14288 or of the fungicide fluazinam (an uncoupler of oxidative phosphorylation), but increases in respiration were greater with SYP-14288 than with fluazinam. These results indicate that SYP-14288 is a promising fungicide that functions as an uncoupler of oxidative phosphorylation. [ABSTRACT FROM AUTHOR]

Microalgae hold remarkable promise to produce food, fuel, and nutraceuticals. To satisfy industrial economics, microalgae are commonly cultivated outdoors in open ponds that are subject to invasions by a suite of pests including predators, competitors, and parasites. Although pests can be mitigated and/or controlled by biocides or pesticides, therapeutic doses of these chemicals often adversely affect the productivity and yield of the target crop. To combat this tradeoff imposed by pesticide treatment, if pesticides are to be used, robust strains with increased pesticide tolerance must be developed and validated for growth at commercial scales. In this study, we evolutionarily engineered strains of the green algae Desmodesmus armatus to tolerate treatment with Omega 500F®, a broad-spectrum agricultural fungicide that is used to treat pest invasions in open, outdoor microalgal ponds. An algal clone library generated through UV mutagenesis was screened for strains that exhibited the greatest growth rates under batch and semi-continuous culture in the lab with and without exposure to Omega. We then screened strains at increasing spatial (i.e., from 96-well plates to 33,000 L raceways) and temporal (i.e., from 5 days to months) scales to select for those strains that were most robust. Our process resulted in the cultivation of two robust field strains that demonstrated tolerance to repetitive dosing with Omega without apparent trade-offs in productivity. This work highlights the utility of non-GM methods, specifically UV mutagenesis, to improve cultivation strains for the production of biomass and bioproducts from microalgae. Moreover, it demonstrates the importance of iterative validation steps in facilitating a successful lab to field transition of engineered strains. [ABSTRACT FROM AUTHOR]

In order to discover highly effective fungicides against Corynespora cassiicola on cucumber, the inhibitory activities of 19 fungicides against mycelial growth, spore germination and germ tube elongation of C. cassiicola were measured. The effects of the 4 selected effective fungicides on mycelial and conidial morphology were also evaluated. The results showed that fluazinam, isopyrazam, fludioxonil and tetramycin exhibited strong inhibitory activities against mycelial growth, spore germination and germ tube elongation at each growth stage of C. cassiicola. The average EC50 value of the four fungicides for inhibiting mycelial growth were 0.516 3, 1.538, 1.605 and 0.648 2 mg/L, respectively. The average EC50 value of inhibiting the spore germination were 0.164 4, 1.359, 1.127 and 0.002 5 mg/L, respectively. The average EC50 value of inhibiting germ tube elongation were 0.189 6, 0.144 7, 0.060 4 and 0.001 5 mg/L, respectively. Fungicides with different modes of action, such as boscalid, chlorothalonil and trifloxystrobin, showed high efficacy against spore germination and tube elongation of C. cassiicola. The average EC50 value of three fungicides to inhibit the spore germination were 1.564, 0.373 0 and 0.021 3 mg/L, respectively. The average EC50 value of inhibiting the germ tube elongation were 0.629 5, 0.233 4 and 0.405 0 mg/L, respectively. But the inhibitory activities against mycelial growth were poor, the average EC50 value were greater than 16 mg/L. After the treatment of fluazinam, isopyrazam, fludioxonil or tetramycin, the morphology of mycelial and conidia was studied. The microscopical observation showed that the mycelial septa spacing decreased, the edge of diaphragm appeared as intumescent and two branches of the main mycelia frequently occurred. In addition, mycelia became distorted and adhesive, the new branches of mycelium were inhibited or conidial growth was metamorphotic. Given that fluazinam, isopyrazam, fludioxonil and tetramycin showed excellent inhibitory virulence against C. cassiicola, these fungicides are potential candidates for the control of C. cassiicola in the field. [ABSTRACT FROM AUTHOR]

In the current study, sensitivity distribution of Sclerotinia sclerotiorum populations to fluazinam was determined using 103 strains collected from the fields of Jiangsu Province of China in 2016–2017 and the resistance risk of fluazinam was assessed. The average EC 50 (50% effective concentration) values and MIC (minimum inhibitory concentration) values of 103 S. sclerotiorum strains against fluazinam were 0.0073 ± 0.0045 μg/ml and < 0.3 μg/ml for mycelial growth, respectively. Nine mutants with low resistance level were obtained from wild type sensitive strains exposed on PDA medium amended with fluazinam and the resistance was stable after their ten transfers on PDA without the fungicide. Compared with the parental strains, the nine fluazinam-resistant mutants decreased in mycelial growth, sclerotial production, pathogenicity and were more sensitive to 0.7 M NaCl. In addition, cell membrane permeability of resistant mutants was higher than that of their parental strains. Cross resistance assay showed that there was no cross-resistance between fluazinam and fludioxonil, dimetachlone, prochloraz, tebuconazole, azoxystrobin, or procymidone in S. sclerotiorum . The above results indicated that there was a low resistance risk for fluazinam in S. sclerotiorum . However, the sensitivity of all fluazinam-resistant mutants to fludioxonil decreased. Sequencing alignment results showed that there were no mutations in the two-component histidine kinase gene ( Shk1 ) of the resistant mutants and the expression levels of Shk1 of three resistant mutants were significantly up-regulated while others were almost the same as their parental strains. These results will contribute to evaluating the resistance risk of fluazinam for management of diseases caused by S. sclerotiorum and further increase our understanding about the mode of action of fluazinam. [ABSTRACT FROM AUTHOR]