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This study aimed to compare the effectiveness of adsorption and photocatalysis techniques at removing the herbicide clomazone (CLO) and the antidepressant known as amitriptyline (AMI) from water. This study employed kinetic models to analyze the removal processes and assess the potential toxicity of the treated water. The structure and morphology of the prepared multi-walled carbon nanotubes were characterized as adsorbents by transmission electron microscopy, X-ray diffraction, Fourier transform infrared techniques, and Raman spectroscopy. The adsorption kinetics of CLO and AMI were studied on the pristine and functionalized multi-walled carbon nanotubes. Kinetic studies were performed by modeling the obtained experimental data using three kinetic models: pseudo-first-order, pseudo-second-order, and Elovich kinetic models. On the other hand, the efficiency of CLO and AMI photodegradation was examined as a function of the type of irradiation (UV and simulated solar irradiation) and type of TiO2 photocatalyst (Aeroxide and Kronos). Under the experimental conditions employed, the reaction followed pseudo-first-order kinetics. Additionally, in order to assess the toxicity of water containing CLO, AMI, and their intermediates, toxicity assessments were conducted using human fetal lung fibroblast cells. The results obtained indicate the effectiveness of both methods and provide valuable insights into their removal mechanisms, contributing to the advancement of sustainable water treatment strategies. [ABSTRACT FROM AUTHOR]

This study portrays the dissipation behaviour of the herbicide mixture of clomazone and 2,4-D (clomazone 20% + 2,4-D ethyl ester 30% EC) in a rice field system. The combined formulation is widely used in India as it controls a broad spectrum of weeds, but its fate in tropical environment and the risks involved to the consumer as well as to the environment are still unexplored. Therefore, a supervised field trial was conducted following the post-emergence application of clomazone 20% + 2,4-D ethyl ester 30% EC at recommended (625 g a.i./ha) and double the recommended dose (1250 g a.i./ha) in rice in two consecutive seasons (Kharif and Rabi). The analytical methods for both clomazone and 2,4-D validated as per the SANTE guideline. The residues of clomazone were extracted by the modified QuEChERS method and analysed by GC-MS/MS, whereas the residues 2,4-D were extracted by classical partitioning method and analysed by LC-MS/MS. The recovery percentage of both the compounds ranged between 86–95% with LOQ 0.01 mg/kg for all matrices (rice grain, straw, husk, and field soil). The dissipation of both the compounds followed first-order kinetics. The half-life of clomazone and 2,4-D in soil ranged between 1.06–1.27 days and 4.74–6.24 days, respectively. The residues of clomazone and 2,4-D were below quantification level (BLOQ) in the harvested rice co-products (rice grain, husk and straw) and soil samples. Therefore, it can be summarised that the application of this herbicide mixture in rice cultivation will not pose any residual toxicity and the rice grains are safe for human consumption. Besides, the soil ecological risk assessment indicated that both the compounds possess low risk towards earthworm and soil arthropods. However, there was a concern about soil algal toxicity, which needs to be reconfirmed by further studies to establish a conclusive inference. [ABSTRACT FROM AUTHOR]

A simple and quick run-time reverse-phase HPLC method for the simultaneous analysis of sulfentrazone and clomazone has been developed and validated in the pesticide formulation of wettable powder. The method was executed using the Agilent Eclipse XDB C-18 column (150 x 4.6 mm; 3.5 µm), alongside the mobile phase comprising 0.1 % (orthophosphoric acid) with Water: Acetonitrile (50:50) at a column rate of flow 1.5 mL per minute, and determination has been carried out in 210 nanometers. The retention time for sulfentrazone as well as Clomazone has been determined at 1.9 as well as 3.0 minutes, correspondingly with a runtime of 5 min. The method's effectiveness has been validated using SANCO recommendations for LOD, LOQ, robustness, accuracy, precision, linearity, selectivity, and specificity. The developed method has been utilized to estimate Sulfentrazone and Clomazone in wettable powder. [ABSTRACT FROM AUTHOR]

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This study aimed to compare the effectiveness of adsorption and photocatalysis techniques at removing the herbicide clomazone (CLO) and the antidepressant known as amitriptyline (AMI) from water. This study employed kinetic models to analyze the removal processes and assess the potential toxicity of the treated water. The structure and morphology of the prepared multi-walled carbon nanotubes were characterized as adsorbents by transmission electron microscopy, X-ray diffraction, Fourier transform infrared techniques, and Raman spectroscopy. The adsorption kinetics of CLO and AMI were studied on the pristine and functionalized multi-walled carbon nanotubes. Kinetic studies were performed by modeling the obtained experimental data using three kinetic models: pseudo-first-order, pseudo-second-order, and Elovich kinetic models. On the other hand, the efficiency of CLO and AMI photodegradation was examined as a function of the type of irradiation (UV and simulated solar irradiation) and type of TiO2 photocatalyst (Aeroxide and Kronos). Under the experimental conditions employed, the reaction followed pseudo-first-order kinetics. Additionally, in order to assess the toxicity of water containing CLO, AMI, and their intermediates, toxicity assessments were conducted using human fetal lung fibroblast cells. The results obtained indicate the effectiveness of both methods and provide valuable insights into their removal mechanisms, contributing to the advancement of sustainable water treatment strategies.

Introduction: Bacterial communities are important for soil functions, but the effect of clomazone on network complexity, composition, and stability is not well studied. Method: In this study, two agricultural soils were used to test the impact of clomazone on bacterial communities, and the two soils were treated with three concentrations of clomazone (0, 0.8, 8, and 80 mg kg1) in an incubator. Results and discussion: Bacterial network nodes, links, and average degrees were all decreased by 9-384, 648-829, and 0.703-2.429, respectively. Based on keystone nodes, the topological roles of the nodes were also influenced by clomazone. Bacterial network composition was also impacted based on the analysis of similarity (ANOSIM) and network dissimilarity. Compared with control and clomazone treatments in both soils, the ANOSIM between control and all clomazone treatments was higher than 0.6, network dissimilarities were 0.97-0.98, shared nodes were 131-260, and shared links were 12-100. The bacterial network stability was decreased by clomazone, with decreased robustness by 0.01-0.016 and increased vulnerability by 0.00023-0.00147 in both soils. There were fewer bacterial network modules preserved after clomazone treatment, and the bacterial network community functions were also impacted in both soils. Based on these results, soil bacterial species connections, modularization, and network stability were significantly impacted by clomazone. [ABSTRACT FROM AUTHOR]

Pre-emergence herbicides can be effective in controlling Sumatran fleabane (Conyza sumatrensis [Retz.] E. Walker) at soybean and other crops. The goal was to evaluate the effectiveness of sulfentrazone/diuron, imazethapyr/flumioxazin, flumioxazin, diclosulam, s-metolachlor, imazethapyr, clomazone and imazapic/imazapyr in controlling Sumatran fleabane for application in the off-season before soybean planting. Three experiments were conducted in the off season, with 9 treatments. The control of Sumatran fleabane was evaluated at 28, 42 and 49 days after application (DAA), at 49 DAA was performed counting of plants per m2. In experiment 1, the worst performance was found for s-metolachlor (58.3% final control), in a situation of lower emergence flow of Sumatran fleabane, with equivalence for the other herbicides. In experiments 2 and 3, with greater emergence flow of Sumatran fleabane, clomazone efficacy stood out (= 86.3% final control). A micro-encapsulated formulation of clomazone was used, which causes greater intoxication to this weed due to its slow release into the soil, and presents less loss to the environment. In conditions of lower emergence of Sumatran fleabane, sulfentrazone/diuron, imazethapyr/flumioxazin, flumioxazin, diclosulam, imazethapyr, clomazone and imazapic/imazapyr were effective in controlling it. Even in this condition, s-metolachlor was not effective in controlling Sumatran fleabane. The application of clomazone was effective in controlling Sumatran fleabane in the three experiments. Clomazone is characterized as an important herbicide for use in the off season in the management of this weed before soybean sowing. [ABSTRACT FROM AUTHOR]

A two-factor field experiment was carried out in 2018-2020 at the Zawady Agricultural Experimental Station (52 ° 03'N and 22 ° 33'E) belonging to the University of Natural Sciences and Humanities in Siedlce in Poland. Tubers of two edible potato cultivars were investigated, i.e. Oberon and Malaga – factor one; in turn, factor two included variants of herbicide application with biostimulators: 1. control object – without preparations, 2. herbicide clomazone + metribuzin (Avatar 293 ZC), 3. herbicide clomazone + metribuzin and biostimulant PlonoStart, 4. herbicide clomazone + metribuzin and biostimulant Aminoplant, 5. herbicide clomazone + metribuzin and biostimulant Agro-Sorb® Folium. The biostimulators used in the research significantly increased the content of total nitrogen and protein nitrogen in tubers, as well as the share of protein nitrogen in total nitrogen in relation to the tubers collected from the control object. The genetic features of the cultivars also determined the concentration of total nitrogen and protein nitrogen in potato tubers.

A two-factor field experiment was carried out in 2018-2020 at the Zawady Agricultural Experimental Station (52°03' N and 22°33' E) belonging to the University of Natural Sciences and Humanities in Siedlce in Poland. Tubers of two edible potato cultivars were investigated, i.e. Oberon and Malaga - factor one; in turn, factor two included variants of herbicide application with biostimulators: 1. control object - without preparations, 2. herbicide clomazone + metribuzin (Avatar 293 ZC), 3. herbicide clomazone + metribuzin and biostimulant PlonoStart, 4. herbicide clomazone + metribuzin and biostimulant Aminoplant, 5. herbicide clomazone + metribuzin and biostimulant Agro-Sorb® Folium. The biostimulators used in the research significantly increased the content of total nitrogen and protein nitrogen in tubers, as well as the share of protein nitrogen in total nitrogen in relation to the tubers collected from the control object. The genetic features of the cultivars also determined the concentration of total nitrogen and protein nitrogen in potato tubers. [ABSTRACT FROM AUTHOR]

Introduction: Soil fungal network composition and stability are important for soil functions, but there is less understanding of the impact of clomazone on network complexity and stability. Methods: In this work, two agricultural soils were used to investigate the impact of clomazone on fungal network complexity, composition, and stability. The two soils were treated with clomazone solution (0, 0.8, 8, and 80 mgkg-1) and kept in an incubator. Results and Discussion: Under the influence of clomazone, the fungal network nodes were decreased by 12-42; however, the average degree was increased by 0.169-1.468 and fungal network density was increased by 0.003-0.054. The keystone nodes were significantly changed after clomazone treatment. Network composition was also impacted. Specifically, compared with control and clomazone treatments in both soils, the shared edges were fewer than 54 in all comparisons, and network dissimilarity was 0.97-0.98. These results suggested that fungal network composition was significantly impacted. The network robustness was increased by 0.0018-0.0209, and vulnerability was decreased by 0.00018-0.00059 in both soils, which indicated that fungal network stability was increased by clomazone. In addition, the functions of network communities were also changed in both soils. These results indicated that clomazone could significantly impact soil fungal networks. [ABSTRACT FROM AUTHOR]

Background: Sugarcane (Saccharum sp.) growers in Louisiana report that the widely used soil residual herbicide, pendimethalin, is less effective at controlling itchgrass (Rottboellia chochinchinensis), possibly through accelerated dissipation from repeated applications. Some growers have started to use another herbicide, clomazone, in place of pendimethalin for itchgrass control when pendimethalin does not provide the necessary control. Little is known about the dissipation of these two herbicides, especially when applied together, in diverse sugarcane soils in Louisiana. Thus, the objective of the research was to measure the dissipation of pendimethalin and clomazone in soils having high itchgrass pressure. Soil samples from five fields were fortified (4 μg g -1 ) with clomazone and pendimethalin and monitored over the course of 163 days under laboratory conditions. Herbicide levels were determined by extracting the herbicides from soil with acetonitrile and analyzing the extracts with high performance liquid chromatography (HPLC)., Results: The results indicate that clomazone is persistent in the soils studied, with a degradation half-life (DT 50 ) of ≥79 days. Pendimethalin dissipates more rapidly in soil with a DT 50 ranging from 7 to 59 days. All itchgrass plants showed injury to herbicide but many grew out of symptoms, and responses were not consistent between soil types., Conclusion: Pendimethalin dissipation varied greatly between soil types, yet clomazone was generally persistent in each soil tested. However, when these soils were seeded with itchgrass, pendimethalin was more effective at controlling itchgrass than clomazone. Although persistent in the soils tested, the leaching potential of clomazone may limit its long-term effectiveness. Published 2024. This article is a U.S. Government work and is in the public domain in the USA., (Published 2024. This article is a U.S. Government work and is in the public domain in the USA.)

Agriculture's global challenge to feed an estimated 7.7 billion people is further exacerbated by less available cropland for production and rapidly changing climate patterns. Pesticides are often utilized to minimize crop losses due to pest infestations; however, problems arise when these chemicals are transported off production acreage, either by storm or irrigation events, and into nearby water bodies. Innovative management practices are needed to not only reduce the volume of runoff, but also to mitigate various pollutants, such as pesticides, within the runoff. One such practice being evaluated involves using rice (Oryza sativa) as a pesticide mitigation tool. While rice plants may serve as a mechanism for phytoremediation, whether the seeds harvested from exposed plants could then be utilized as a human food source is an unanswered question. Thirty round mesocosms (55 L volume; 56 cm diameter; six replicates per treatment) were established with rice and exposed to aqueous concentrations of the pesticides clomazone, propanil, or cyfluthrin, as well as a mixture of the three pesticides. Six replicates with rice and no pesticide exposure served as controls. Initial pesticide exposure took place 8 weeks post-planting and continued once a week for 5 weeks. Rice plants, unmilled seeds, and mesocosm sediment were collected from each mesocosm 2 weeks after seed formation began and analyzed for pesticide concentrations using gas chromatography. Concentrations of pesticides in unmilled seed were below detection for individual exposures of clomazone, propanil, and cyfluthrin. When rice was exposed to the pesticide mixture, the mean ± SE unmilled seed cyfluthrin concentration was 14.8 ± 1.25 µg kg−1. These small-scale, preliminary studies offer insight into the possibility of using immature rice plants as a phytoremediation tool, while harvesting its grain after plant maturation for human consumption. Further research is needed to address this question on a larger scale and with multiple pesticide mixtures. [ABSTRACT FROM AUTHOR]

Abstract Background We report a method to estimate carbon assimilation based on isotope ratio-mass spectrometry (IRMS) of 13CO2 labeled plant tissue. Photosynthetic carbon assimilation is the principal experimental observable which integrates important aspects of primary plant metabolism. It is traditionally measured through gas exchange. Despite its centrality in plant research, gas exchange performs poorly with rosette growth habits typical of Arabidopsis thaliana, mutant lines with limited biomass, and accounts poorly for leaf shading. Results IRMS-based carbon assimilation values from plants labeled at different light intensities were compared to those obtained by gas exchange, and the two methods yielded similar values. Using this method, we observed a strong correlation between 13C content and labeling time (R2 = 0.999) for 158 wild-type plants labeled for 6 to 42 min. Plants cultivated under different light regimes showed a linear response with respect to carbon assimilation, varying from 7.38 nmol 13C mg−1 leaf tissue min−1 at 80 PAR to 19.27 nmol 13C mg−1 leaf tissue min−1 at 500 PAR. We applied this method to examine the link between inhibition of the 2C-methyl-d-erythritol-4-phosphate (MEP) pathway and suppression of photosynthesis. A significant decrease in carbon assimilation was observed when metabolic activity in the MEP pathway was compromised by mutation or herbicides targeting the MEP pathway. Mutants affected in MEP pathway genes 1-DEOXY-d-XYLULOSE 5-PHOSPHATE SYNTHASE (DXS) or 1-HYDROXY-2-METHYL-2-(E)-BUTENYL 4-DIPHOSPHATE SYNTHASE (HDS) showed assimilation rates 36% and 61% lower than wild type. Similarly, wild type plants treated with the MEP pathway inhibitors clomazone or fosmidomycin showed reductions of 52% and 43%, respectively, while inhibition of the analogous mevalonic acid pathway, which supplies the same isoprenoid intermediates in the cytosol, did not, suggesting inhibition of photosynthesis was specific to disruption of the MEP pathway. Conclusions This method provides an alternative to gas exchange that offers several advantages: resilience to differences in leaf overlap, measurements based on tissue mass rather than leaf surface area, and compatibility with mutant Arabidopsis lines which are not amenable to gas exchange measurements due to low biomass and limited leaf surface area. It is suitable for screening large numbers of replicates simultaneously as well as post-hoc analysis of previously labeled plant tissue and is complementary to downstream detection of isotopic label in targeted metabolite pools.

It is believed that indaziflam gives a longer period of weed control compared to clomazone, irrespective of the type or texture of the soil. Thus, the aim of this study was to evaluate pre-emergent control in five problematic weed species of family Poaceae to sugarcane, using the herbicides indaziflam and clomazone in two soils of different textures. Two experiments were carried out, one in a soil of a sandy-loam texture and the other in a clayey soil. For both experiments, a randomised block design of split plots was chosen, with four replications. The treatments consisted of the herbicides indaziflam (75 and 100 g ai ha-1), clomazone (1080 g ai ha-1) and a control with no herbicide. In the subplots, the treatments were Digitaria horizontalis, Panicum maximum, Rottboellia cochinchinensis, Urochloa decumbens and Urochloa plantaginea. Both herbicides were more effective in the clayey soil, but with indaziflam (100 g ai ha-1), more than 90% control of the weeds remained after 240 days after application (DAA), whereas for clomazone, control remained only up to 90 DAA. The herbicide clomazone did not satisfactorily control the weeds in the sandy-loam soil. The herbicide indaziflam did not control U. decumbens in the sandy-loam soil. D. horizontalis and R. cochinchinensis were the most sensitive species to the herbicide indaziflam, irrespective of soil texture. [ABSTRACT FROM AUTHOR]

The Soybean (Glycine max (L.) Merr.) is a kind of oilseed crop and also a good source of nutrition for human beings, poultry and other animals. Clomazone and acetochlor are two kinds of pesticides of great concern that are widely used to protect soybean from weeds. The purpose of this study was to evaluate the food safety of soybean after applying clomazone and acetochlor. For this purpose, the contents of clomazone and acetochlor in green soybean, green straw, mature soybean, and mature straw collected from six locations in different provinces of China were determined by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The recoveries of the compounds at different concentration levels were 86%-110% while the relative standard deviations (RSDs) ranged from 2% to 31 11%. The limits of quantification (LOQs) for each matrix of the two herbicides were 0.01 mg/kg. Residues of clomazone and acetochlor in soybean at harvest time were all below 0.01 mg/kg at the recommended dosage. [ABSTRACT FROM AUTHOR]

Abstract Worldwide, conventional agriculture makes extensive use of pesticides. Although the effects of herbicides are relatively well known in terms of environmental impacts on non-target organisms, there is very little scientific evidence regarding the impacts of herbicide residues on aquatic arthropods from tropical conservation areas. This study evaluates for the first time the toxicity of the herbicides ametryn, atrazine, and clomazone on the aquatic insect Limnocoris submontandoni (Hemiptera: Naucoridae). The lethal concentration (LC50) of herbicides was evaluated for these insects, as well as the effect of the herbicides on the insects’ tissues and testicles. The estimated LC50 was 1012.41, 192.42, and 46.09 mg/L for clomazone, atrazine, and ametryn, respectively. Spermatocyte and spermatid changes were observed under the effect of atrazine, and effects on spermatogenesis were observed for some concentrations of clomazone, with apparent recovery after a short time. Our results provide useful information on the effects of herbicide residues in aquatic systems. This information can help minimize the risk of long-term reproductive effects in non-target species that have been previously overlooked in ecotoxicology studies.

This research aimed to investigate the removal efficiency of the pesticide clomazone, as well as two pharmaceutically active compounds, ciprofloxacin and 17α-ethynilestradiol, using sustainable heterogeneous photocatalysis with newly synthesized binary coupled ZnO/MeO x nanopowders (ZnO/MgO, ZnO/CeO 2 , and ZnO/ZrO 2) as photocatalysts, under various experimental conditions (catalyst loading and initial pH). The newly synthesized nanomaterials were characterized using XRD, SEM-EDS, TEM, DLS, Raman and UV/Vis spectroscopy, and zeta potential. The XRD proved the nanocrystalline size of the synthesized photocatalysts in the range 40−17 nm. The difference in morphology (shape and size) was determined and all elements were quantified using SEM-EDS. TEM images confirmed the successful formation of ZnO/MeO x heterojunctions. DLS measurements showed distributions with mean hydrodynamic particle diameters of 1226, 1042, and 944 nm for ZnO/MgO, ZnO/CeO 2 , and ZnO/ZrO 2 powders, respectively. Raman also proved the successful preparation of binary nanomaterials. Considering the UV/Vis spectroscopy results, bandgap energy was found to be in the range 3.241–3.249 eV. BET analysis was used to determine specific surface area, 13.6852, 11.0554, and 8.5519 m2/g for ZnO/MgO, ZnO/CeO 2 , and ZnO/ZrO 2. Optimal photocatalytic experimental conditions were defined using chemometrics. Chemical oxygen demand and ion chromatography analyses additionally confirmed the successful pollutant removal. The mechanism of CIP photocatalytic degradation and photocatalyst reutilization study were conducted under optimal conditions. After two consecutive runs, the reutilization study revealed that there was no loss of photocatalytic efficiency, while the contribution of various reactive species was: h + ˃ • OH ads > • OH free. And finally, the toxicity of mixtures was observed on wheat samples. [Display omitted] • Newly synthesized binary coupled ZnO based (ZnO/MgO, ZnO/CeO2 and ZnO/ZrO2) nanopowders. • Optimal experimental conditions were determined using chemometrics. • ZnO/ZrO2 had the highest performance where 77% of CLO, 86% of CIP, and 71% of EE2 was removed. • The toxicity of selected pollutants and their photodegradation intermediates was observed. [ABSTRACT FROM AUTHOR]

Background: We report a method to estimate carbon assimilation based on isotope ratio-mass spectrometry (IRMS) of 13CO2 labeled plant tissue. Photosynthetic carbon assimilation is the principal experimental observable which integrates important aspects of primary plant metabolism. It is traditionally measured through gas exchange. Despite its centrality in plant research, gas exchange performs poorly with rosette growth habits typical of Arabidopsis thaliana, mutant lines with limited biomass, and accounts poorly for leaf shading. Results: IRMS-based carbon assimilation values from plants labeled at different light intensities were compared to those obtained by gas exchange, and the two methods yielded similar values. Using this method, we observed a strong correlation between 13C content and labeling time (R2 = 0.999) for 158 wild-type plants labeled for 6 to 42 min. Plants cultivated under different light regimes showed a linear response with respect to carbon assimilation, varying from 7.38 nmol 13C mg−1 leaf tissue min−1 at 80 PAR to 19.27 nmol 13C mg−1 leaf tissue min−1 at 500 PAR. We applied this method to examine the link between inhibition of the 2C-methyl-d-erythritol-4-phosphate (MEP) pathway and suppression of photosynthesis. A significant decrease in carbon assimilation was observed when metabolic activity in the MEP pathway was compromised by mutation or herbicides targeting the MEP pathway. Mutants affected in MEP pathway genes 1-DEOXY-d-XYLULOSE 5-PHOSPHATE SYNTHASE (DXS) or 1-HYDROXY-2-METHYL-2-(E)-BUTENYL 4-DIPHOSPHATE SYNTHASE (HDS) showed assimilation rates 36% and 61% lower than wild type. Similarly, wild type plants treated with the MEP pathway inhibitors clomazone or fosmidomycin showed reductions of 52% and 43%, respectively, while inhibition of the analogous mevalonic acid pathway, which supplies the same isoprenoid intermediates in the cytosol, did not, suggesting inhibition of photosynthesis was specific to disruption of the MEP pathway. Conclusions: This method provides an alternative to gas exchange that offers several advantages: resilience to differences in leaf overlap, measurements based on tissue mass rather than leaf surface area, and compatibility with mutant Arabidopsis lines which are not amenable to gas exchange measurements due to low biomass and limited leaf surface area. It is suitable for screening large numbers of replicates simultaneously as well as post-hoc analysis of previously labeled plant tissue and is complementary to downstream detection of isotopic label in targeted metabolite pools. [ABSTRACT FROM AUTHOR]

The adsorption behaviour of the herbicide clomazone on inorganic and organically modified montmorillonite from the Bogovina deposit in Serbia was investigated. Montmorillonite was modified first with NaCl and then with organic complexes such as hexadecyltrimethylammonium bromide (HDTMA) and phenyltrimethylammonium chloride (PTMA). Changes in the surface properties and morphology of the montmorillonite before and after the modification with various concentrations of organic complexes were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Adsorption of clomazone on all examined samples was investigated using the batch adsorption method. Montmorillonite modified with HDTMA-bromide displayed greater uptake of the clomazone compared to the PTMA-montmorillonite, and both organically modified montmorillonites displayed greater uptake of the herbicide compared to the inorganic montmorillonite. Comparing the Freundlich coefficient and maximum adsorbed clomazone quantity values obtained by Langmuir model, the levels of adsorption of clomazone decreased in the following order: HDTMA-montmorillonite with 1.00 cation-exchange capacity (CEC) saturation > HDTMA-montmorillonite with 0.75 CEC saturation > PTMA-montmorillonite with 1.00 CEC saturation > PTMA-montmorillonite with 0.75 CEC saturation > HDTMA-montmorillonite with 0.50 CEC saturation > HDTMA-montmorillonite with 0.25 CEC saturation > PTMA-montmorillonite with 0.50 CEC saturation > PTMA-montmorillonite with 0.25 CEC saturation > Na-montmorillonite > raw sample. The type and content of an organic cation plays an important role in the behaviour of clomazone in a solid/liquid system. It is concluded that organically modified montmorillonite from Bogovina might be used as an effective adsorbent for clomazone. [ABSTRACT FROM AUTHOR]

Abstract Contamination of water sources due to herbicide is of great concern. Clomazone is a pesticide with a high contamination potential which could possibility lixiviate to water streams. Changes caused by residual herbicide include flora modifications which are generally detrimental for some species. The lack of morphological studies performed in aquatic plants exposed to herbicide-contaminated environments has encouraged the development of our research. For the first time, we present a study that aimed to evaluate leaf injuries visible to the naked eye as well as microscopical effects which may be caused by clomazone on Pistia stratiotes. Pistia stratiotes was subjected to five concentrations of clomazone. Our analysis showed leaf injuries, especially after 15 days of clomazone application. Hormesis was observed when the water lettuce was subjected to the lower concentrations. Total leaf area showed increase following by reduction while injured until reaching the highest concentration. Although the concentrations of clomazone tested in our study are not lethal to water lettuce, such herbicide have still caused morphoanatomical damages on leaves which advocates for the use of P. stratiotes as a bioindicator of the presence of herbicides such as clomazone in water.

The use of herbicides, in particular clomazone and glyphosate, applied in isolation or in a tank mix, is very common in rice, soybeans, corn and sugarcane fields and the drift of these herbicides can cause damage in sensitive species grown nearby. The purpose of this work was to evaluate the effects of the simulated drift of clomazone and glyphosate applied in an isolated way or mixed in a spray on lemon tree plants. The experiment was installed in a greenhouse in pots with a capacity of 15 L containing sieved soil and an experimental design of randomized blocks was adopted, arranged in a 3 x 5 factorial scheme, with four replications. Plants with two years of development were used. The treatments tested were, clomazone, glyphosate and both mixed, and the decreasing doses of the recommended commercial product: 100, 75, 50, 25 and 0% to simulate herbicide drift. Was evaluated variables, phytotoxicity at 14, 28, 46 and 100 days after application of treatments; plant height, crown volume, the trunk diameter of the rootstock, trunk diameter of the graft and trunk diameter at the grafting point at 0 and 100 days after application of treatments; and liquid assimilation of CO2 at 10 and 60 days after application of treatments. Among the tested herbicides, the one that presented the highest phytotoxicity and the lowest liquid assimilation of CO2 in lemon tree plants was the glyphosate + clomazone mixture. Increases in trunk diameter of the rootstock, grafting point, graft and crown volume did not show significant effects with simulated drift. The plant height presented a greater reduction with the increase of the herbicide doses, mainly glyphosate. That there are considerable losses in lemon tree plants when herbicide drift occurs, mainly by glyphosate and its mixture with clomazone. [ABSTRACT FROM AUTHOR]

The study concerned dissipation of metazachlor and clomazone, herbicides widely used in rapeseed (Brassica napus L. subsp. napus) protection, applied to the clay soil under field and laboratory conditions. Furthermore, the uptake of these pesticide from soil by rapeseed plants was investigated under field conditions. An additional aim of this work was to modify the QuEChERS method for the determination of metazachlor and clomazone in the plant material. Analytical procedures for metazachlor and clomazone qualification and quantification in rapeseed plants and soil were developed, using gas chromatography with an micro electron capture detector (GC-μECD) and a mass detector (GC-MS/MS QqQ) as confirmation. Dissipation kinetics of herbicide residues in soil were described as first-order equations. The analytical performance was very satisfactory and confirmed that the methods meet the requirements of the European Commission. In the conducted field experiments it was found that dissipation of clomazone and metazachlor in clay soil follows first-order kinetics (R2 between 0.964 and 0.978), and half-lives were 9.5 days and 10.2 days for clomazone and metazachlor, respectively. Under laboratory conditions, dissipation of clomazone and metazachlor in soil also follows first-order kinetics (R2 between 0.937 and 0.938), and half-lives were 8.8 days and 5.7 days for clomazone and metazachlor, respectively. Residues of both herbicides in rape plants 22 days after application of herbicides were below the maximum residue levels for Brassica plants. Metazachlor and clomazone dissipate very fast in clay soil and their uptake by rape plants is very low. [ABSTRACT FROM AUTHOR]

Bearded sprangletop (Leptochloa fusca spp. fasicularis) is a problematic weed in California rice (Oryza sativa) production. Historically, bearded sprangletop is controlled with clomazone in California rice fields. The continuous use of clomazone and lack of crop rotation in rice fields resulted in resistance to clomazone in several bearded sprangletop. The objective of this research was to determine the clomazone mechanism of resistance of two bearded sprangletop populations in California rice by investigating clomazone absorption, translocation, and metabolism under controlled environmental conditions in two resistant (CRBS1 and CRBS2) and one susceptible (S) populations. Absorption and translocation of 14C-clomazone were similar in R and S. Clomazone metabolism, as determined by inhibition of cytochrome P450 enzymes with malathion and determining clomazone metabolites profile, was different between S and R 3 days after treatment. Bearded sprangletop pretreated with malathion was 2-fold more sensitive to clomazone than when treated with clomazone alone, suggesting that cytochrome P450-mediated clomazone metabolism might be involved in the mechanism of resistance. An HPLC-MS/MS analysis revealed differences in clomazone metabolism between R and S biotypes. Hydroxymethylclomazone was the most abundant metabolite found in R plants with three and five-fold more abundant in CRBS1 and CRBS2, respectively, when compared to S plants. 5-ketoclomazone, the known toxic metabolite of clomazone, accumulated 2-fold more in S plants than in R plants at 72 h after treatment. This research shows that clomazone is metabolized differently between R and S populations of bearded sprangletop and that P450 monooxidation is likely involved in the mechanism of resistance. Unlabelled Image • Increased metabolism of clomazone is the mechanism of resistance in bearded sprangletop. • Hydroxymethylclomazone accumulated more in clomazone resistant plants than susceptible. • 5-ketoclomazone accumulated more in susceptible than in clomazone resistant bearded sprangletop plants. [ABSTRACT FROM AUTHOR]

• Pt modified MWCNT were used as a sensor for succesfull determination of pesticide clomazone. • Proper characterization of the modified material revealed that uniform disperison of Pt is on the nano level. • Clomazone can be determined by DPSV with good reproducibility in the concentration range from 0.61 to 20.56 ng cm−3, with the limit of detection of 0.38 ng cm−3. Novel electrochemical sensor based on Pt supported multiwalled carbon nanotubes is used for determination of pesticide clomazone in aqueous media via differential pulse stripping voltammetry (DPSV). Since clomazone is stable and readily soluble in water, it is often found in water sources. Hence, its determination in the environment is of utmost importance. Herein, clomazone is determined in 0.1 M phosphate buffer solution at pH 7.0 in the concentration range of 0.61–20.56 ng cm−3, with LOQ = 0.61 and LOD = 0.38. These results are in the same range with HPLC/DAD, which is used as comparative method. It is shown that DPSV is a facile and efficient way for determination of clomazone in contrast to precise but field-impractical HPLC. Mechanistic approach in explaining electrode processes is correlated to structural aspects of the synthesized sensor. HRTEM data reveals a uniform distribution of Pt nanoparticles on the MWCNT support as a source of crucial, structural and electronic changes. Furthermore, characterisation of Raman results indicates the existence of structural defects, which is believed to be the leading reason for improvement in sensing response. [ABSTRACT FROM AUTHOR]

The use of long-residual herbicides can have adverse effects on terrestrial ecosystems. This study assessed the acute and chronic toxicity and avoidance behavior of Eisenia andrei earthworms exposed to nominal concentrations of clomazone, indaziflam, and sulfentrazone, using recommended commercial formulations for sugarcane cultivation. The formulations included Gamit® 360 CS (360 g L−1 of the active ingredient - a.i. - clomazone), Boral® 500 SC (500 g L−1 of a.i. sulfentrazone), and Alion® (500 g L−1 of a.i. indaziflam). Boral® 500 SC induced avoidance at concentrations as low as 1 mg kg−1, while Gamit® 360 CS and Alion® exhibited higher avoidance at 50–75 mg kg−1 and 75–100 mg a.i. kg−1, respectively. Reproduction tests showed significant impacts from Gamit® 360 CS (EC 50 : 0.572 mg kg−1, EC 10 : 0.2144 mg kg−1) and Boral® 500 SC (EC 50 : 0.3941 mg kg−1, EC 10 : 0.134 mg kg−1). Acute toxicity tests indicated moderate toxicity for Gamit® 360 CS (LC 50 : 184.12 mg kg−1) and Boral® 500 SC (LC 50 : 1000 mg kg−1). Gamit® 360 CS reduced biomass at all concentrations, while Boral® 500 SC influenced only at higher levels (500 and 1000 mg kg−1). Results suggest significant acute risks with Gamit® 360 CS, while chronic exposure raises concerns for both Gamit® 360 CS and Boral® 500 SC, indicating potential long-term risks. Alion®'s acute effects were inconclusive, but chronic exposure hints at a possible risk. These findings provide crucial insights for environmental agencies establishing protective limits against herbicide exposure to non-target soil invertebrates. [Display omitted] • Herbicide toxicity was tested on earthworms with Oxisols. • Only the herbicide Gamit® 360 CS (a.i. clomazone) caused mortality in Eisenia andrei at doses up to 200 mg kg−1. • All herbicides tested showed negative effects on earthworm reproduction. • The avoidance tests were the most sensitive for the substances investigated in the study. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa), early watergrass (Echinochloa oryzoides); EWG; biotypes resistant (R) and susceptible (S) to thiocarbamates and aryloxyphenoxy propionate herbicides), and late watergrass (Echinochloa phyllopogon; LWG; R and S biotypes) were exposed to clomazone for 7 d. Whole-plant change in fresh weight and B-carotene concentrations were measured. For growth, the No Observed Effect Concentrations (NOECs) were 7.9, 0.21, 0.21, 0.46, and 0.46 µM clomazone for rice, EWG (R), EWG (S), LWG (R), and LWG (S), respectively, while the concentrations causing 25% inhibition in response (IC25s) were 5.6, 0.46, 0.42, 0.92 and 0.79 µM clomazone, respectively. For rice, EWG (R), EWG (S), LWG (R), and LWG (S), the B-carotene NOECs were 0.21, < 0.08, < 0.08, 0.08 and 0.46 µM clomazone, respectively and IC25s were 0.42, 0.08, 0.08, 0.33 and 0.54 µM, respectively. At a field-relevant clomazone application rate resistance to clomazone was observed in EWG (R) and LWG (R) as measured by growth and B-carotene, respectively. Due to similar sensitivity between rice and late watergrass, use of clomazone in rice culture may require the use of a safening technique.Rice and EWG (S) were exposed to 14C-labeled clomazone to determine accumulation, biotransformation and mass balance. In terms of extractable 14C, rice contained more total residues than EWG (p < 0.05), but the concentration in EWG was significantly higher (p < 0.01). More metabolized residue was measured in EWG compared to rice (p < 0.01). Both species produced hydroxylated forms of clomazone, B-D-glucoside conjugates, and unidentified polar metabolites. The suspected active metabolite, 5-ketoclomazone, was found at a significantly higher concentration in EWG vs. rice (21 ± 2 vs. 5.7 ± 0.5 pmol g-1, respectively; p < 0.01). Qualitatively and quantitatively, more clomazone metabolism was observed in the relatively sensitive EWG compared to rice.R and S biotypes of EWG and LWG were exposed to clomazone alone and in combination with P450 inhibitors. Growth reduction (GR25, GR50, and GR75) values were lower for S biotypes than for R biotypes (p < 0.05) with exposure to clomazone alone indicating resistance to clomazone in the R biotypes. In combination with clomazone disulfoton increased 20-d growth in LWG (R) by as much as 5-fold, compared to application of clomazone alone. Oxydemeton methyl increased 20-d growth by as much as 6-fold. Disulfoton and oxydemeton methyl reduced !)-carotene levels compared to treatment with clomazone alone. For EWG (S), disulfoton increased 4-d growth by 46% and increased B-carotene levels by 52%. Demeton-S increased B-carotene levels by 48%. At 6800 g ai ha-1 PBO increased growth and B-carotene levels by 28 and 48%, respectively. These results indicate that P450 enzymes serve both to activate and detoxify clomazone.

Abstract Background Recently, we reported immunological and hematological perturbations in Swiss albino mice exposed to clomazone (CMZ) (Nassef, The Egyptian Journal of Experimental Biology (Zoology) 13(1):91–101, 2017). Aim To continue searching immunological perturbations of CMZ, the main goal of the current study was to investigate the probable immunobiochemical perturbations caused by CMZ and to evaluate the alleviating role of vitamin C. Methods To asses this goal, mice were intraperitoneally (i.p.) injected with vitamin C (1136 μM/kg), CMZ (46 μM/kg), or CMZ plus vitamin C with the same dose of each, daily for 4 weeks. Changes in relative weights of immune-related organs (spleen and thymus), renal functions (urea and creatinine), liver functions [alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and total protein], and immunoglobulin (Ig) isotype (IgA, IgG, and IgM) concentrations in addition to the proliferative capacity of CMZ-exposed murine lymphocytes were investigated. Results Results showed that CMZ injection caused a significant decrease in body weight gain along with significant decrease in the relative weights of the spleen and thymus. Values of ALT, AST, and ALP were significantly elevated, while total protein and LDH were significantly decreased in CMZ-exposed mice. CMZ injection led to significant increases in the levels of serum urea and creatinine. Moreover, the levels of serum IgA, IgG, and IgM in CMZ-treated mice were significantly lower than those in PBS-treated mice. Reduced lymphocyte proliferation capacity was observed in CMZ-treated mice. Interestingly, pre-treatment of vitamin C to CMZ-exposed mice mildly alleviated CMZ-induced immunobiochemical perturbations. Therefore, vitamin C mildly alleviated CMZ-induced immunobiochemical impacts, but it was not completely protective. Conclusion Further studies are needed to assess the relationships between antioxidants and CMZ-induced immunobiochemical perturbations.

TiO2 nanopowders were produced by sol-gel technique using TiCl4 as a starting material. For the preparation of crystalline anatase with developed surface area, this aqueous solution has been mixed with 0.05 M or 0.07 M (NH4)2SO4 solution in a temperature-controlled bath. The pH values of the suspension were 7, 8 or 9. According to the x-ray diffraction (XRD) analysis the anatase crystallite sizes were about 12 nm, which coincided with the average particle size revealed by scanning electron microscopy (SEM). The Raman scattering measurements have shown the presence of a small amount of highly disordered brookite phase in addition to dominant anatase phase with similar nanostructure in all synthesized powders. BET measurements revealed that all synthesized catalysts were fully mesoporous, except the sample synthesized with 0.07 M (NH4)2SO4 at pH=9, which had small amount of micropores. The photocatalytic degradation of herbicide Clomazone was carried out for both the pure active substance and as the commercial product (GAMIT 4-EC) under UV irradiation. The best photocatalytic efficiency was obtained for the catalyst with the largest specific surface area, confirming this parameter as crucial for enhanced photocatalytic degradation of the pure active substance and commercial product of herbicide Clomazone. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45018]

ABSTRACT The nitric oxide acts on the antioxidant system of plants and can discontinue the damage of herbicides elicitors of oxidative stress that cause the disruption of membranes and leakage of cellular contents. In order to evaluate the protective effect of nitric oxide in electrolytes leakage, leaf segments of the Puita INTA CL rice cultivar were incubated with 0, 5, 50, 500 and 5,000 μM clomazone (360 g a.i. L-1), oxadiazon (250 g a.i. L-1), oxyfluorfen (240 g a.i. L-1) and the formulated mixture of paraquat (200 g a.i. L-1) + diuron (100 g a.i. L-1) to obtain the maximum potential conductivity of 50% (MPC50). Subsequently, leaf segments were pre-treated with 0, 200 and 2,000 μM of sodium nitroprusside (SNP) for four hours and further incubated for 48 hours with 0, 0.5, 1, 2 and 4 times the concentration of the herbicide that caused the CMP50, and the protective effect was reassessed in the presence of nitric oxide scavenger, cPTIO. The MPC50 was caused by exposure to 188.9, 273.4, 410.2 + 205.1 and 917.0 μM of Oxadiazon, Oxyfluorfen, Paraquat + Diuron and Clomazone. Pretreatment with 200 μM of SNP reduced electrolyte leakage in leaf segments exposed to 2 and 4 times the MPC50 to oxadiazon and paraquat + diuron, while 2,000 μM reduced the damage caused by oxyfluorfen, at the same concentrations. Also, 200 and 2,000 μM of SNP were efficient for clomazone, and the protection was confirmed by cPTIO in all cases.

Few effective management strategies remain for controlling herbicide-resistant Echinochloa crus-galli (L). Beauv. In midsouthern USA rice production. Repeated use of the same herbicide site of action (SOA) is ineffective and may be overcome by targeting alternative SOAs. At relatively low risk for evolution of resistance, very-long-chain fatty acid (VLCFA)-inhibiting herbicides (WSSA Group 15) such as acetochlor are promising candidates for weed control in rice. Field experiments were conducted in 2016 and 2017 to evaluate the impact of acetochlor formulated as Warrant® on E. crus-galli control as part of a complete herbicide program in both imidazolinone- (Clearfield) and quizalofop- (Provisia) resistant rice systems. These studies were designed as a randomized complete block with a nontreated, weedy check included for comparison. In the Clearfield experiment, acetochlor at 1,050 or 1470 g ai ha−1 or clomazone at 336 g ai ha−1 was applied delayed preemergence (DPRE) 1) alone, 2) followed by imazethapyr at 70 g ai ha−1 early-postemergence (EP), or 3) followed by imazethapyr EP followed by imazethapyr pre-flood (PREFLD). Herbicide treatments were identical in the Provisia experiment, with the exception being that quizalofop at 120 g ai ha−1 was applied postemergence (POST) instead of imazethapyr. Rice injury was <15% following all DPRE applications in two of the three site-years; however, rainfall events shortly after application resulted in more severe rice injury 2 WAT in 2017, particularly following acetochlor applications (49–78%). Overall, clomazone-containing programs provided superior E. crus-galli control throughout the season and rice yielded higher in clomazone-than acetochlor-containing programs. Oftentimes, clomazone- and acetochlor-containing programs were comparable within single- and multi-pass programs; however, the success of acetochlor-containing programs was more affected by rainfall and dependent on POST herbicides. Should acetochlor be labeled for use in rice, it should be applied EP followed by sequential POST applications to provide weed control and yield comparable to standard programs used today. • Clomazone-containing programs provided superior E. crus-galli control over acetochlor programs in dry-seeded rice. • Rice yielded higher in clomazone- than acetochlor-containing programs because of early-season interference from E. crus-galli. • Acetochlor should be applied sequentially postemergence to provide weed control and rice yield comparable to standard programs. [ABSTRACT FROM AUTHOR]

• Clomazone resistance co-segregated with ALS resistance in E. phyllopogon progenies. • Arabidopsis transformed with CYP81A s exhibited clomazone resistance. • Differential herbicide metabolizing functions were suggested in CYP81A members. Clomazone is a herbicide used in the cultivation of numerous crops due to its unique site of action and effectiveness on weeds. The differences in clomazone susceptibility among plants have been attributed to the differences in their complex clomazone metabolic pathways that are not fully understood. We previously identified two CYP81A cytochrome P450 monooxygenases that metabolize five chemically unrelated herbicides in multiple-herbicide resistant Echinochloa phyllopogon. Since the resistant E. phyllopogon have decreased clomazone susceptibility, involvement of these P450s in clomazone resistance was suggested. In this study, we revealed that each P450 gene endowed Arabidopsis thaliana (Arabidopsis) with clomazone resistance. Consistent with this, clomazone resistance co-segregated with resistance to other herbicides in F 6 progenies of crosses between susceptible and resistant E. phyllopogon , suggesting that the P450s are involved in differential clomazone susceptibility in E. phyllopogon. Arabidopsis transformations of the other seven CYP81A s of E. phyllopogon found that two more genes, CYP81A15 and CYP81A24 , decreased Arabidopsis susceptibility to clomazone. Differences in substrate preference between clomazone and a herbicide that inhibits acetolactate synthase were suggested among the four CYP81A P450s. This study provides insights into clomazone metabolism in plants. [ABSTRACT FROM AUTHOR]

The plant safener dietholate can be used for seed treatments (ST) to improve the selectivity of clomazone in rice cultures, thus allowing the application of higher dosages of this herbicide. The objective of this research was to evaluate the interaction between seed fungicide-insecticide treatments with and the plant safener dietholate in irrigated rice. Three experiments were carried out, and the first of them was conducted in a laboratory, following a completely randomized experimental design with four replications. Different ST and treatment-to-sowing intervals were evaluated. The second and third experiments were performed in field conditions, in a completely randomized block design with four replications. In experiment two, seeds were treated with different fungicides, in association or not with dietholate; while in experiment three, the effect of the ST with fungicides and dietholate with clomazone application were assessed. The results evidenced that the association between carboxin + thiram + dietholate reduced seed germination, vigor, and the dry mass of shoot of rice plants. The longer it takes between ST and sowing, the more rice seed germination is negatively affected. The association between fungicides and dietholate may have been antagonistic, and thus interfered with the culture growth potential. [ABSTRACT FROM AUTHOR]

Weeds have direct effect upon reduction of yield and quality of tobacco, hindering the good performance of other work operations. Indirectly, being a host to many insect vectors of various diseases, they are associated with infections of tobacco. Clomazone is a herbicide with wide application in weed management and our goal was to determine its efficiency in the control of weeds in tobacco seedlings. Experiments were conducted through in seedbeds of the Scientific Tobacco Institute-Prilep. Tests were made with napropamide-based preparations Ohinol 50-S in a rate of 2 kg/ha and Devrinol 45F in a rate of 3 l/ha, used prior to transplanting. Gamit 4EC (clomazone) rates were 0.7; 0.8; 0.9 and 1 l/ha used after transplanting. Sampling and assessment of weed were performed by the method of 1 m2 squares. The effectiveness of herbicides in control of weeds was evaluated by counting weed populations in plots treated with herbicide and those in the untreated check. The highest efficiency was obtained with the herbicide Gamit - 95.97% at 1 l/ha, 93,76% at 0,9 l/ha and 91.94% at 0,8 l/ha. Herbicides based on napropamide gave poor efficiency. [ABSTRACT FROM AUTHOR]

Main conclusion: Carotenoid accumulation and chromoplast development in orange were perturbed by carotenoid inhibitors, and candidate genes were identified via transcriptomic analysis. The role of CsPHT4;2 in enhancing carotenoid accumulation was revealed.Carotenoids are important plant pigments and their accumulation can be affected by biosynthesis inhibitors, but the genes involved were largely unknown. Here, application of norflurazon (NFZ), 2-(4-chlorophenylthio)-triethylamine hydrochloride (CPTA) and clomazone for 30 days to in vitro cultured sweet orange juice vesicles caused over-accumulation of phytoene (over 1000-fold), lycopene (2.92 μg g−1 FW, none in control), and deficiency in total carotenoids (reduced to 22%), respectively. Increased carotenoids were associated with bigger chromoplasts with enlarged plastoglobules or a differently crystalline structure in NFZ, and CPTA-treated juice vesicles, respectively. Global transcriptomic changes following inhibitor treatments were profiled. Induced expression of 1-deoxy-D-xylulose 5-phosphate synthase 1 by CPTA, hydroxymethylbutenyl 4-diphosphate reductase by both NFZ and CPTA, and reduced expression of chromoplast-specific lycopene β-cyclase by CPTA, as well as several downstream genes by at least one of the three inhibitors were observed. Expression of fibrillin 11 (CsFBN11) was induced following both NFZ and CPTA treatments. Using weighted correlation network analysis, a plastid-type phosphate transporter 4;2 (CsPHT4;2) was identified as closely correlated with high-lycopene accumulation induced by CPTA. Transient over-expression of CsPHT4;2 significantly enhanced carotenoid accumulation over tenfold in 'Cara Cara' sweet orange juice vesicle-derived callus. The study provides a valuable overview of the underlying mechanisms for altered carotenoid accumulation and chromoplast development following carotenoid inhibitor treatments and sheds light on the relationship between carotenoid accumulation and chromoplast development. [ABSTRACT FROM AUTHOR]

Abstract We designed an indoor mesocosm experiment to investigate the long-term effects of exposure to clomazone, a widely used herbicide, on soil microbial communities and their nitrogen (N) cycling functions. Clomazone was applied to two typical soils from China at three concentrations: 0.8 (the recommended dosage), 8 and 80 mg kg−1 soil dry weight, and the mix was incubated for 90 days. Samples were removed periodically for assay with several techniques. The half-lives of clomazone in this experiment were 11–126 d. Results were significant only for the highest clomazone concentration. Next-generation sequencing of the 16S and 18S rDNA genes revealed that bacterial diversity significantly decreased whereas fungal abundance increased after day 60 but with no detectable effect on the microbial community. Hierarchical cluster and principal coordinates analysis revealed that the bacterial community structure was negatively impacted. Linear discriminant analysis of effect size identified Sphingomonas and Arthrobacter as the predominant bacterial species. Finally, we measured soil NH 4 + and NO 3 − concentrations and used real-time PCR to analyze the abundance of the N-cycling genes , nifH and amoA. In the first 30 days, the NO 3 −-N content and the number of ammonia-oxidizing bacteria increased. N 2 -fixing bacteria were inhibited after 60 days, but the NH 4 +-N concentration remained unchanged and was likely provided by ammoniation. Graphical abstract Unlabelled Image Highlights • The effects of clomazone on soil microorganism and N 2 -cycling have been studied. • High dosage clomazone decreased bacterial abundance and changed the composition. • Clomazone could increase fungal abundance. • High dosage clomazone significantly impact the abundance of nif H and amo A. [ABSTRACT FROM AUTHOR]

A laboratory bioassay was conducted to investigate the susceptibility of cucumber to the residual activity of clomazone in loamy and sandy soils. The effects of three different levels of soil moisture (20, 50 and 70% field capacity - FC) was also examined. Clomazone was applied in concentration series of 0.047-6 mg a.i./kg soil. Plants grew for 21 days, upon which period physiological parameters (content of carotenoids, chlorophyll ɑ and chlorophyll b) were measured. Clomazone caused leaf bleaching and reduction in pigments content in cucumber leaves in both types of soil at all levels of soil moisture, and the degree of change depended on application rates. Inhibition was higher in plants grown in the sandy soil, while the least sensitive were cucumber plants grown in both types of soil with 20% FC. The findings in this study showed moderate cucumber susceptibility to clomazone residues in loamy and sandy soils.

The process of mechanical harvesting of sugarcane generates a large deposition of straw on the soil surface, providing a coverage that several studies have found important for reducing the weed population. Although such coverage reduces weed infestations, additional management, including chemical control, is still needed. Thus, this study aimed to evaluate the leaching of atrazine, pendimethalin, metribuzin, clomazone, diuron and hexazinone in sugarcane straw. The experiment was conducted at the School of Agronomic Engineering at UNESP (Sao Paulo State University) - Botucatu/SP. The sugarcane straw was collected in the field, cut and placed in quantities of 10t ha-1 in the capsules used as experimental units. The experimental design was completely randomized, using six herbicide treatments and four replications. Within 24 hours after the herbicides were applied in capsules with straw, five different rainfalls (5, 10, 20, 50 and 100mm) were simulated. The leached water was collected for chromatographic analysis. The herbicide percentages that crossed the straw layer were statistically correlated with the rainfall amount by the Mitscherlich model that compares the facility of herbicide removal from sugarcane straw. In summary, pendimethalin did not present quantified transposition of the product by sugarcane straw even with a rain simulation of 100 mm. Furthermore, two different profiles of facility to transpose the herbicides in straw were found: one for metribuzin and hexazinone that crossed quickly through the straw layer and another for atrazine, diuron and clomazone that required more rainfall to be leached from coverage to the soil according to the maximum removable amount of each herbicide.

This study was conducted to establish a weed management system based on the sequential application of pre-emergence (PRE) and post-emergence (POST) herbicides for soybean production in Primorsky krai. Field experiments were conducted for two years in a field located in Bogatyrka, Primorsky krai, Russia (N43°49′, E131°36′). No herbicide application resulted in significant soybean yield loss, 0.03–0.3 t ha−1, which is more than 91.6% yield loss compared with that of the weed-free plot. The PRE application of acetochlor showed good weed control efficacy (greater than 90% weed control) with acceptable soybean safety (less than 10% soybean damage), while the other PRE herbicides performed poorly in terms of weed control. The POST application of bentazon + acifluorfen, bentazon, and imazamox at 30 days after soybean sowing (DAS) showed good weed control efficacy with good soybean safety. Neither the PRE nor POST application alone showed a sufficient soybean yield protection, resulting in much lower soybean yield than the weed-free plot. The sequential application of acetochlor (PRE), followed by either bentazon + acifluorfen (POST) at 30 DAS in 2012 or bentazon + imazamox (POST) at 60 DAS in 2013 showed the best performance in soybean yields, 1.7 t and 1.9 t ha−1, respectively, provided with 724.5 US$ and 1155.6 US$ ha−1 of economic returns. For alternative PRE herbicides of acetochlor, which is now banned, our tests of the sequential application of S-metolachlor with other POST herbicides and the sole application of other PRE herbicides revealed that S-metolachlor and clomazone could also be considered. Our results thus demonstrate that the sequential applications of PRE and POST herbicides should be incorporated into the weed management system for soybean production in Primorsky krai, Russia.

Potato (Solanum tuberosum L.) is grown in over 160 countries. Weed competition and environmental stressors during the vegetative growth stage significantly impact crop yields. An experiment was conducted from 2012 to 2014 in Poland to assess the effect of herbicides linuron + clomazone (L+CH) and metribuzin (M) as well as herbicides mixed with biostimulants (linuron + clomazone and algae extract of Ecklonia maxima—auxins and gibberellins (L+CH+E) and metribuzin + sodium p-nitrophenolate, sodium o-nitrophenolate and sodium 5-nitroguaiacolate (M+S)) on weed infestation, marketable yield and yield components of the following three table potato cultivars: Bartek, Gawin and Honorata. In plots where potato had been treated with herbicides and herbicides mixed with biostimulants, a decline in the fresh matter of weeds was observed, ranging from 72.4% to 96.1%, which was followed by an increase in potato marketable yield (from 27.5% to 61%) and improved parameters of S. tuberosum yield components, compared with the control. Linear correlation coefficients indicated that the following characteristics: marketable yield, weight of tubers per plant and average weight per tuber were associated with weed infestation determined prior to potato harvest.

ABSTRACT: Synergism is a desired result in the interaction between herbicides because it provides many benefits, among which the reduction of doses and the increment of control efficiency, and because it positively signals for the joint application of herbicides. The objective of this study is to evaluate the effect of the association of saflufenacil with other herbicides that promote oxidative stress on the development of Euphorbia heterophylla as well as to analyze if the resulting interactions are antagonistic, additive or synergistic. The experiment was conducted in pots, in a greenhouse, using a completely randomized design with four replications. Treatments consisted of saflufenacil (0, 1,2, 2,32, 4,47, 8,63, 16,65 g ha-1) alone and associated with clomazone (288 and 504 g ha-1), metribuzin (105.6 and 206.4 g ha-1) and paraquat (20 and 40 g ha-1), as well as these herbicides applied alone at the same doses described above. Twenty-one days after the application (DAA), the shoot dry matter (SDM) of plants was evaluated in each experimental unit. The Limpel-Colby method was used to calculate the expected response of the herbicide interaction. All combinations of saflufenacil with clomazone, metribuzin and paraquat were considered synergistic. Among the treatments associated with saflufenacil, those including metribuzin at the dose of 105.6 g ha-1 were the ones that provided the most promising results, which stood out for the greater reductions of wild poinsettia shoot dry matter, compared to the application of saflufenacil alone.

ABSTRACT: Herbicides are inputs with a high volume of use in agricultural production systems for weed management; however, the environmental contamination they cause is a reality. The objective of this research was to evaluate the tolerance of tree species used for the phytoremediation of herbicides in the soil, to atrazine, clomazone and 2,4-D, through the evaluation of photosynthetic indices. Thus, a randomized block design experiment was conducted with four replications, in a 4 x 5 factorial arrangement, where the first factor represented the herbicides atrazine, clomazone and 2,4-D and the control treatment without herbicide (water). The second factor consisted in the use of pre-selected tree species for the phytoremediation of soils with residues of the products [Eremanthus crotonoides DC. (candeia), - Richeria grandis Vahl (richeria), Protium heptaphyllum (Aubl) Marchand, (breu-branco) Kielmeyera latrophyton Saddi, Kew Bull, (pau-santo) Calophyllum brasiliense Cambess (guanandi)]. The herbicides were applied through dishes placed under the culture containers of the plants, when they presented eight months of development. After 15 days from the herbicide application, the visual intoxication, stomatal conductance (Gs), transpiration rate (E), CO2 concentration in the substomatal chamber (Ci), and water use efficiency (WUE) were evaluated. The herbicides affected differently the physiological characteristics of the tree species; atrazine was the most harmful product. Individuals under the effect of 2,4-D and clomazone presented lower variation for their physiological characteristics, compared to the respective control treatments. Breu-branco, despite showing low visual intoxication provided by the herbicides, was the most affected species by the products. On the other hand, candeia was the most tolerant species to the action of the herbicides.

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant LSA (Landesanstalt Sachsen‐Anhalt) submitted a request to the competent national authority in Germany to modify the existing maximum residue levels (MRLs) for the active substance clomazone in chamomiles and plantains. The data submitted in support of the request were found to be sufficient to derive MRL proposals for the crops under consideration. Adequate analytical methods for enforcement are available to control the residues of clomazone in plant matrices on the crops under consideration at the validated limit of quantification (LOQ) of 0.01 mg/kg. Based on the risk assessment results, EFSA concluded that the short‐term and long‐term intake of residues resulting from the use of clomazone according to the reported agricultural practice is unlikely to present a risk to consumer health. Restrictions on crop rotation as an appropriate risk mitigation measure should be taken into consideration at national level in order to avoid the occurrence of clomazone residues in rotational crops.

The aim of this work was to compare the dynamics of the degradation of herbicides commonly used in brassica vegetables. Series of plot field experiments were carried out in planting cauliflower in 2012-2014. The amount of herbicide residues with the maximum residue level (MRL) determined by the Regulation (EC) No. 396/2005 and with requirements of non-residue production (up to 10 μg/kg of active ingredient in harvested product) was compared. Napropamide, clomazone and dimethachlor were applied before planting and pendimethalin, S-metolachlor, pyridate, ethametsulfuron, dimethenamid, metazachlor, quinmerac, picloram, clopyralid, cycloxydim, fluazifop, propaquizafop and quizalofop were applied after planting the cauliflower. Besides fluazifop and quizalofop, all tested herbicides showed a fast degradation and can be recommended for non-residue production. The amount of fluazifop residues did not fall below the MRL even 6 weeks after application. Residues of post-emergently applied quizalofop were detected in cauliflower 10-44 days after application in most of the samples at concentration 9-73 μg/kg (below the MRL). [ABSTRACT FROM AUTHOR]

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With the advent of new implantation technologies of sugarcane crop, the aim of this study was to evaluate the selectivity of herbicides in pre-budded cultivars of sugarcane seedlings. With the formation of seedlings from a gem of high sanity in tubes with substrates, seedlings, with an average height of 20 cm, were transplanted to 12 L pots filled with soil. The experimental design was a completely randomized factorial arranged in a (3x8), being the cultivars, CTC 7, CTC 14 and RB966928; and the herbicides (g ha-1): ametryn + trifloxysulfuron-sodium (1280 + 32.4); imazapic (150); halosulfuron (150); isoxaflutole (90); ametryn (5000); ametryn + clomazone (1500 + 1000) and amicarbazone (1500), applied 10 days after transplanting; and a control without application. The three cultivars of sugarcane visually studied responded differently to the application of herbicide treatments tested, being the herbicides ametryn + trifloxysulfuron, imazapic, halosulfuron and ametryn which caused less phytotoxicity. However, when confronting the other parameters analyzed, it was observed that ametryn + trifloxysulfuron, isoxaflutole, ametryn, ametryn + clomazone and amicarbazone for CTC7 cultivar, ametryn + clomazone and amicarbazone for CTC14 and amicarbazone for RB966928, caused loss to the initial development of the crop. [ABSTRACT FROM AUTHOR]

Our goal was to evaluate the effects of simulated drift of clomazone e glyphosate applied alone or in a tank mixture over grapevines of Merlot variety. The experiment was set in a randomized blocks design, arranged in a 3x4+1 factorial scheme, with four replications. In factor A, the herbicides clomazone, glyphosate and the clomazone + glyphosate tank mixture was allocated and in B, doses of the same herbicides, representing drift simulations, of: 0, 25, 50, 75 and 100% of recommended doses. In 14, 28, 46 and 100 days after treatment, we evaluated the phytotoxicity of herbicides over grapevines. We determined the characteristics related to the increase of vegetative growth at the time of the experiment set-up and at the end of the experiment (100 DAT). At 10 and 20 DAT we also determined the net assimilation of CO2 on grapevines that were treated with herbicides. The clomazone and the glyphosate applied either alone or in a tank mixture caused phytotoxicity in grapevine crops. The grapevine demonstrated to be sensitive, even to low herbicide doses, thus requiring caution when using pulverization of glyphosate, clomazone or the mixture of clomazone + glyphosate, in areas close to crops. [ABSTRACT FROM AUTHOR]

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