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Agro-industries should adopt effective strategies to use agrochemicals such as glyphosate herbicides cautiously in order to protect public health. This entails careful testing and risk assessment of available choices, and also educating farmers and users with mitigation strategies in ecosystem protection and sustainable development. The key to success in this endeavour is using scientific research on biological pest control, organic farming and regulatory control, etc., for new developments in food production and safety, and for environmental protection. Education and research is of paramount importance for food and nutrition security in the shadow of climate change, and their consequences in food production and consumption safety and sustainability. This review, therefore, diagnoses on the use of glyphosate and the associated development of glyphosate-resistant weeds. It also deals with the risk assessment on human health of glyphosate formulations through environment and dietary exposures based on the impact of glyphosate and its metabolite AMPA—(aminomethyl)phosphonic acid—on water and food. All this to setup further conclusions and recommendations on the regulated use of glyphosate and how to mitigate the adverse effects.

The aim of this study was to understand the uncertainty of estimating loads for observed herbicides and nutrients during a flood event and provide guidance on estimator selection. A high-resolution grab sampling campaign (258 samples over 100 h) was conducted during a flood event in a tropical waterway in Queensland, Australia. Ten herbicides and three nutrient compounds were detected at elevated concentrations. Each had a unique chemograph with differences in transport processes (e.g. dependence on flow, dilution processes and timing of concentration pulses). Resampling from the data set was used to assess uncertainty. Bias existed at lower sampling efforts but depended on estimator properties as sampling effort increased: the interpolation, ratio and regression estimators became unbiased. Large differences were observed in precision and the importance of sampling effort and estimator selection depended on the relationship between the chemograph and hydrograph. The variety of transport processes observed and the resultant variability in uncertainty suggest that useful load estimates can only be obtained with sufficient samples and appropriate estimator selection. We provide a rationale to show the latter can be guided across sampling periods by selecting an estimator where the sampling regime or the relationship between the chemograph and hydrograph meet its assumptions: interpolation becomes more correct as sampling effort increases and the ratio becomes more correct as the r 2 correlation between flux and flow increases (e.g. > 0.9); a stratified composite sampling approach, even with random samples, is a promising alternative. [ABSTRACT FROM AUTHOR]

Providing a mechanistic understanding of the crucial roles of the phytohormone auxin has been an important and coherent aspect of plant biology research. Since its discovery more than a century ago, prominent advances have been made in the understanding of auxin action, ranging from metabolism and transport to cellular and transcriptional responses. However, there is a long road ahead before a thorough understanding of its complex effects is achieved, because a lot of key information is still missing. The availability of an increasing number of technically advanced scientific tools has boosted the basic discoveries in auxin biology. A plethora of bioactive small molecules, consisting of the synthetic auxin-like herbicides and the more specific auxin-related compounds, developed as a result of the exploration of chemical space by chemical biology, have made the tool box for auxin research more comprehensive. This review mainly focuses on the compounds targeting the auxin co-receptor complex, demonstrates the various ways to use them, and shows clear examples of important basic knowledge obtained by their usage. Application of these precise chemical tools, together with an increasing amount of structural information for the major components in auxin action, will certainly aid in strengthening our insights into the complexity and diversity of auxin response. [ABSTRACT FROM AUTHOR]

A study was planned to evaluate effectiveness of new pre-mix herbicide metsulfuron methyl+chlorimuron ethyl for management of sedges and broadleaf weeds in transplanted rice at research farm of Punjab Agricultural University, Ludhiana for three years. The treatments comprised of metsulfuron methyl+chlorimuron ethyl 3, 4 and 5g/ha, azimsulfuron 20g/ha and metsulfuron 4 g/ha as post emergence and unsprayed control, replicated four times. The results indicated that the density and biomass of sedges and broadleaf weeds was significantly less in metsulfuron methyl+chlorimuron ethyl 4 and 5g/ha than 3g/ha, azimsulfuron 20g/ha, metsulfuron 4g/ha and unsprayed control. Application of metsulfuron methyl+chlorimuron ethyl 4g/ha applied in rice recorded significantly highest average grain yield of 7.31t/ha. There was a negative linear relationship between weed biomass and grain yield (r=-24.08). Correlation matrix revealed that all the yield attributes showed higher correlation with metsulfuron methyl+chlorimuron ethyl 4g/ha. Post emergence application of metsulfuron methyl+chlorimuron ethyl at 4g/ha resulted in effective control of broadleaf weeds and sedges in transplanted rice. [ABSTRACT FROM AUTHOR]

This review mainly focuses on the physiological function of 4-hydroxyphenylpyruvate dioxygenase (HPPD), as well as on the development and application of HPPD inhibitors of several structural classes. Among them, one illustrative example is represented by compounds belonging to the class of triketone compounds. They were discovered by serendipitous observations on weed growth and were developed as bleaching herbicides. Informed reasoning on nitisinone (NTBC, 14), a triketone that failed to reach the final steps of the herbicidal design and development process, allowed it to become a curative agent for type I tyrosinemia (T1T) and to enter clinical trials for alkaptonuria. These results boosted the research of new compounds able to interfere with HPPD activity to be used for the treatment of the tyrosine metabolism-related diseases. [ABSTRACT FROM AUTHOR]

The temporal selectivity of an herbicide refers to the time interval required between its soil application and crop sowing to prevent damage to crop development and reproduction. Using field bioassays, this study aimed to determine the temporal sensitivity of the herbicide saflufenacil when used with a crop. The study was conducted in two time periods during 2011/2012 and 2012/2013 and employed a split-plot, randomized block experimental design. The main plots were assigned to seven time intervals between herbicide application and bean sowing (0, 5, 10, 15, 25, 35, and 50 days), and the subplots were assigned to groups in which saflufenacil was absent or present (0 and 29.4 g ai ha-1). We determined the stand and the plant height at 7, 14, and 21 days after sowing (DAS), and the first pod height, the number of pods per plant, the number of seeds per pod and the grain yield at maturity. Saflufenacil negatively affected the development of the IPR-Tiziu bean; at 21 DAS, the stand and the plant height at maturity were the variables most sensitive to the herbicide. A minimum interval of 15 days between herbicide spraying and bean sowing was necessary to prevent a reduction in grain yield. [ABSTRACT FROM AUTHOR]

ABSTRACT Atrazine (ATR) is one of the most commonly applied broad-spectrum herbicides. Although ATR is well known to be a biologically hazardous molecule with potential toxicity in the immune system, the molecular mechanisms responsible for ATR-induced immunotoxicity remain unclear. In this study, we found that the immunotoxic properties of ATR were mediated through the induction of apoptotic changes in T lymphocytes. Mice exposed to ATR for 4 weeks exhibited a significant decrease in the number of spleen CD3+ T lymphocytes, while CD19+ B lymphocytes and nonlymphoid cells were unaffected. ATR exposure also led to inhibition of cell growth and induction of apoptosis in human Jurkat T-cells. Importantly, ATR triggered the activation of caspase-3 and the cleavage of caspase-8 and PARP, whereas it did not affect the release of cytochrome c from the mitochondria in Jurkat T-cells. In addition, ATR activated the unfolded protein response signaling pathway, as indicated by eIF2 α phosphorylation and CHOP induction. Our results demonstrate that ATR elicited an immunotoxic effect by inducing ER stress-induced apoptosis in T-cells, therefore providing evidence for the molecular mechanism by which ATR induces dysregulation of the immune system. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 998-1008, 2016. [ABSTRACT FROM AUTHOR]

Phosphinotricin (L-PPT) is the active compound of a broad-spectrum herbicide. Acute poisoning with L-PPT has various clinical manifestations, including seizures and convulsions. However, the exact mechanism of L-PPT toxicity remains unclear. The present study addressed the role of L-PPT, in the excitability of striatal medium-sized spiny neurons (MSNs). In whole-cell current-clamp experiments, L-PPT increased the input resistance (Ri), decreased the rheobase and increased the firing frequency of action potentials. In voltage-clamp experiments, L-PPT inhibited the inward-rectifying potassium (Kir) currents. Finally, the effects of L-PPT mimicked the inhibition of Kir channels with Ba on neuronal excitability. Altogether, these results suggest that the herbicide L-PPT is a modulator of Kir channels in MSNs. Thereby, Kir channels are potent regulators of the excitability of MSNs and reduced open probability of these channels would generate a powerful upregulation of neuronal output. This effect may represent a possible mechanism for L-PPT dependent neuronal toxicity. [ABSTRACT FROM AUTHOR]

BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model ( RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel-tilled plot, was used to investigate effects of 50 and 100% corn ( Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor and metolachlor oxanilic acid ( OXA). RESULTS The model accurately simulated field-measured metolachlor transport in drainage. A 3 year simulation indicated that 50% residue removal reduced subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4-5-fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, approximately twofold reductions in OXA losses were simulated with residue removal. CONCLUSION The RZWQM indicated that, if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase owing to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease as a result of the more rapid movement of the parent compound into the soil. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

BACKGROUND The photodegradation of imazosulfuron ( IMZ), a potent broad-spectrum herbicide, was investigated under simulated rice field conditions. Previous reports have indicated that it is photolabile, but have failed to report radiation intensity or determine a quantum yield, precluding extrapolation to environmental rates. Therefore, the objective of this investigation was to determine the photolytic rate of IMZ under simulated rice field conditions and how it is influenced by environmental factors such as turbidity, salinity and temperature. RESULTS IMZ was efficiently photolyzed in all solutions and fitted pseudo-first-order kinetics. Degradation was faster in HPLC-grade water than in field water. Field-relevant variances in temperature, turbidity and salinity did not significantly influence degradation. The experimentally derived quantum yield for direct photolysis (2.94 × 103) was used to predict the half-life of IMZ in a California rice field (3.6 days). CONCLUSIONS Aqueous photolysis is predicted to be an important process in the overall degradation of IMZ in the environment, regardless of variances in salinity, organic matter and temperature. Based on the predicted half-life of IMZ in a California rice field (3.6 days), state-mandated holding periods for field water post- IMZ application (30 days) are expected to allow for sufficient clearance of the herbicide (>98%), preventing significant contamination of the environment upon release of tailwater. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Pyrene-containing water-soluble probes for the fluorescent detection of nitroaromatic compounds (NACs), such as explosive components (2,4-DNT and 2,4,6-TNT) and herbicides (2,4-dinitrocresol, 2,4-DNOC), in aqueous media are reported. In the probes, the introduction of surface-active hydrophilic 'heads' at the periphery of lipophilic (i.e., hydrophobic) pyrene 'tails' resulted in the formation of highly fluorescent micelle-like aggregates/pre-associates in aqueous solutions at concentrations of ≤10−5 m. The enhanced fluorescence quenching of the herein reported architectures is achieved in the presence of ultra-trace amounts of TNT or 2,4-DNT with values of Stern-Volmer quenching constant close to 1×105 m−1 and a detection limit as low as 182 ppb. The most hydrophilic probes demonstrated higher response to 2,4-DNT over TNT. Filter paper test strips impregnated with 1×10−5 m solutions of the probes were able to detect TNT, 2,4-DNT, and other NACs at levels as low as 50 ppb in water. [ABSTRACT FROM AUTHOR]

In the present study, the field dissipation and transport of quizalofop- p-ethyl by water and sediment runoff were investigated in sunflower experimental cultivation under Mediterranean conditions. The cultivation was carried out in silty clay soil plots with two different slopes of 1 and 5 %. The soil dissipation rate of quizalofop- p-ethyl was fast and can be described by both single first-order (SFO) and Gustafson and Holden (first-order multi compartment (FOMC)) kinetics. The half-life of quizalofop- p-ethyl ranged from 0.55 to 0.68 days and from 0.45 to 0.71 days when SFO and FOMC kinetics were applied, respectively. No herbicide residues were detected below the 10-cm soil layer. A single detection of quizalofop- p-ethyl was observed in runoff water (3 days after application (DAA)) at relatively low concentrations (from 1.70 to 2.04 μg L). In sediment, it was detected in the samplings of 3 and 25 DAA at concentrations that never exceeded 0.126 μg g. The estimated total losses of quizalofop- p-ethyl as percentage of the initial applied active ingredient were low both in water and sediment (less than of 0.021 and 0.005 %, respectively). Quizalofop- p-ethyl residues were detectable for 18 DAA in the stems and leaves of the plants and 6 DAA in the root system. No herbicide residues were detected in inflorescences and seeds of sunflower plants. Experimental data showed minimal risk for the contamination of soil and adjacent water bodies. [ABSTRACT FROM AUTHOR]

ZJ0273 (propyl 4-(2-(4, 6-demethoxy pyrimidin-2-yloxy) benzylamino) benzoate) is a novel pyrimidynyloxybenzoic-based herbicide developed in China for oilseed crop. This study was aimed to construct new strains capable of degrading naphthalene and ZJ0273 by protoplast fusion between Amycolatopsis sp. M3-1 and Pseudomonas sp. Nai8. Eight recombinant strains were successfully produced, and the strains could simultaneously utilize ZJ0273 and naphthalene as the sole carbon and energy source, respectively. One of recombinant strains, MN6 with higher degrading efficiency, was chosen for further study. Under the condition of pH 7.0, 30 °C, ZJ0273 and naphthalene degradation percent by the recombinant strain MN6 could reach 65.10 % (20 days) and 88.46 % (48 h), respectively. According to the identified six metabolites (M1-M6) by LC-MS/MS, biodegradation pathway of ZJ0273 was proposed. ZJ0273 biodegradation catalyzed by the recombinant strain MN6 involved continuous biocatalytic reactions such as de-estering, hydrolysis, acylation, C-N cleavage, de-methyl, and ether cleavage reactions. [ABSTRACT FROM AUTHOR]

The isotope dilution mass spectrometry (IDMS) is a highly efficient method for tackling the ion suppression in complex matrix by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), but a lack of commercial internal standards is a limiting factor for these analyses. Herein, an economical and efficient strategy for the synthesis of 13C3-simazine via a three-step procedure was developed. The isotope-labeled internal standard was used for determination of simazine residue in soil samples. The quantitation method has a limit of detection of 0.015 µg/kg and quantitation of 0.08 µg/kg. The inter-day and intra-day precision of the method were below 4.6%. Recovery values were ranged between 92.9% and 99.2%. All the samples obtained from six provinces in China contained from 1 to 62 µg/kg of simazine. [ABSTRACT FROM AUTHOR]

With the objective of finding valuable herbicidal candidates, a series of new 5-heterocycloxy-3-methyl-1-substituted-1H-pyrazoles were synthesized and their herbicidal activities were evaluated. The bioassay results showed that some compounds exhibited excellent herbicidal activities at the concentration of 100 mg/L, and compound 5-chloro-2-((3-methyl-1-(2,2,2-trifluoroethyl)-1H-pyrazol- 5-yl)oxy)pyrimidine showed bleaching activity to green weeds. In greenhouse conditions, this compound also showed excellent post-emergence herbicidal effect against Digitaria sanguinalis L. at the dosage of 750 g a. i. ha-1. [ABSTRACT FROM AUTHOR]

Research has been conducted within the framework of the French Initiative for Coral Reefs (IFRECOR) to assess pesticide pollution levels in the coral reef trophic webs in French Polynesia. Unexpected widespread contamination by herbicides was found in algae, fishes and macro-invertebrates located at various levels of the reef trophic web. Concentrations in organisms investigated were for the majority below the lowest observable effect level and do not pose a dietary risk to native population who subsist on these fish. However, the widespread contamination may affect the reef ecosystem in the future as coral symbiotic algae, Symbidinium sp. ( Dinophyta) are particularly sensitive to photosystem II herbicides, particularly the substituted urea and triazine derivatives. [ABSTRACT FROM AUTHOR]

Constructed wetlands are an effective and practical option for removing pesticide pollution from runoff or subsurface drainage water. The objective of this study was to assess the efficiencies of a ditch with a bundle of straw placed in its centre and a vegetated pond installed in grass cover bands at downstream of a drained plot. The dissipation rates of three herbicides and three fungicides were monitored on four substrates commonly found in constructed wetlands (two soils, sediment and straw). The influence of water content was determined in a sequence of three steps (flooded-unsaturated-flooded) over 120 days. The pesticide dissipation rates observed during the 120 days of incubation ranged from 1.4 to 100 %. Isoproturon and 2,4-MCPA (MCPA) showed the highest dissipation rates, which ranged from 61.0 to 100 % of the applied quantities during the 120 days of incubation. In contrast, boscalid and tebuconazole showed the lowest dissipation rates, which ranged from 1.4 to 43.9 % of the applied quantities during the 120 days of incubation. The estimated DT values ranged from 20.5 days to more than 1 year and were influenced by the substrate water content. The soil and straw substrates had the lowest DT values during the unsaturated conditions, whereas the sediments had the lowest DT values during the flooded conditions. These results could be explained by an adaptation of microbial communities to their environmental conditions. Thus, the most favourable conditions of dissipation for soils and straw are observable when the drainage ceases (spring and summer). However, favourable conditions occur all year for the sediments, except when the constructed wetlands are dry. The results suggest that the dissipation of pesticides in constructed wetlands contributes to the long-term effectiveness of these buffer zones for reducing water pollution. [ABSTRACT FROM AUTHOR]

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 (Universidade Estadual Paulista) -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 leachedfrom coverage to the soil according to the maximum removable amount of each herbicide. [ABSTRACT FROM AUTHOR]

Lemna minor L., a widely used model plant for toxicity tests has raised interest for its application to phytoremediation due to its rapid growth and ubiquitous occurrence. In rural areas, the pollution of water bodies with heavy metals and agrochemicals poses a problem to surface water quality. Among problematic compounds, heavy metals (copper) and pesticides are frequently found in water bodies. To establish duckweed as a potential plant for phytoremediation, enzymatic and antioxidative stress responses of Lemna minor during exposure to copper and a chloroacetamide herbicide were investigated in laboratory studies. The present study aimed at evaluating growth and the antioxidative and glutathione-dependent enzyme activity of Lemna plants and its performance in a scenario for phytoremediation of copper and a chloroacetamide herbicide. Lemna minor was grown in Steinberg medium under controlled conditions. Plants were treated with CuSO (ion conc. 50 and 100 μg/L) and pethoxamide (1.25 and 2.5 μg/L). Measurements following published methods focused on plant growth, oxidative stress, and basic detoxification enzymes. Duckweed proved to survive treatment with the respective concentrations of both pollutants very well. Its growth was inhibited scarcely, and no visible symptoms occurred. On the cellular basis, accumulation of O and HO were detected, as well as stress reactions of antioxidative enzymes. Duckweed detoxification potential for organic pollutants was high and increased significantly with incubation. Pethoxamide was found to be conjugated with glutathione. Copper was accumulated in the fronds at high levels, and transient oxidative defense reactions were triggered. This work confirms the significance of L. minor for the removal of copper from water and the conjugation of the selective herbicide pethoxamide. Both organic and inorganic xenobiotics induced different trends of enzymatic and antioxidative stress response. The strong increase of stress responses following copper exposure is well known as oxidative burst, which is probably different from the much more long-lasting responses found in plants exposed to pethoxamide. Lemna sp. might be used as a tool for phytoremediation of low-level contamination with metals and organic xenobiotics, however the authors recommend a more detailed analysis of the development of the oxidative burst following copper exposure and of the enzymatic metabolism of pethoxamide in order to elucidate the extent of its removal from water. [ABSTRACT FROM AUTHOR]

A multi-step synthesis of 4,6-dimethoxyaurone derivatives was carried out from phloroglucinol and chloroacetonitrile, and the products were characterized by 1H NMR, 13C NMR, and HRMS. The preliminary bioassays showed that some products exhibited herbicidal activity against dicotyledonous plant Brassica campestris L. [ABSTRACT FROM AUTHOR]

For regulatory and scientific purposes, there is a need to understand the sensitivity of a wider variety of wild species of amphibians and the sensitivities within their life stages to chemicals of widespread use such as herbicides. We investigated the acute toxic effects of the herbicide formulation Focus Ultra [with the active ingredient (a.i.) cycloxydim plus solvent naphtha and sodium dioctylsulphosuccinate as added substances] on embryos and early stage larvae of the Moroccan painted frog ( Discoglossus scovazzi). Different clinical signs (twitching, convulsion, and narcosis) occurred at 40 and 80 mg/L in embryos (4 and 8 mg a.i./L) and narcotic effects (total immobilization or irregular escape responses) at 10, 15, and 20 mg/L in larvae (1, 1.5, and 2 mg a.i./L). Growth inhibition (total length), starting at 20 mg/L in embryos and 2.5 mg/L in larvae (2 and 0.25 mg a.i./L, respectively) was understood as sign of toxicity (retardation) and not as sign of teratogenicity. However, the connection to teratogenesis remained unclear though total length reduction occurred at concentrations <20 % of the 96-h LC value and at a minimum concentration that inhibits growth of only 17 % of the 96-h LC value. Starting at 20 mg/L, mortality in embryos significantly increased and at 15 mg/L in early larvae (2 and 1.5 mg a.i./L, respectively). Mortality of larvae was enhanced during the first 24 h of exposure to 15 and 20 mg/L (1.5 and 2 mg a.i./L). Morphology of the embryos remained unobtrusive. In contrary, axial malformations significantly increased in the early larvae starting at 10 mg/L (1 mg a.i./L), a concentration free of lethal effects. In all considered end points, larvae were significantly more sensitive than embryos, probably because of developmental and physiological properties or different exposure and bioavailability of the compound. Focus Ultra induced comparable lethal and immobilization effects in D. scovazzi as it does to standard test organisms in pesticide approval. However, to validate the apparent safety in the field, which is based on calculated surface water concentrations of the a.i., more data on real contamination levels is necessary (e.g., peak concentrations, concentrations of added substances). Furthermore, sufficient buffer strips between the farmland and amphibian ponds must be considered, and the effects of the substance on terrestrial life stages have not been assessed yet. [ABSTRACT FROM AUTHOR]

Galvanostatic electrolyses are performed in a filter-press reactor to investigate the electrochemical degradation of picloram (100 mg L −1 , from a commercial herbicide formulation) using a boron-doped diamond (BDD) or β-PbO 2 anode. The effect of pH (3, 6, or 10), applied current density ( j apl = 10, 30, or 50 mA cm −2 ), and absence or presence of Cl – ions (25 mM) in the supporting electrolyte (aqueous 0.10 M Na 2 SO 4 ) is investigated, while the picloram concentration, solution chemical oxygen demand ( COD ) and total organic carbon content ( TOC ), and energy consumption are monitored as a function of electrolysis time. From the obtained results, it is clear that the electrochemical degradation of picloram is possible using either of the anodes, but with different overall performances. In general, the presence of Cl – ions in the supporting electrolyte (leading to electrogenerated active chlorine) has a positive effect on the performance of both anodes, except for TOC abatement using the BDD anode; the best electrodegradation performances are attained at pH values around 6, when HClO is the predominant active-chlorine species. Faster rates of initial electrodegradation of picloram and of solution TOC abatement are obtained as j apl is increased, but, as expected, lower energy consumptions are always attained at the lowest value of j apl . The performances of the two anodes are virtually the same in the initial degradation of picloram; however, the BDD anode greatly surpasses the β-PbO 2 anode in the abatement of solution COD or TOC . This confirms the importance of the oxidation power of the anode, even when indirect oxidation by active chlorine plays a concomitant role. [ABSTRACT FROM AUTHOR]

Controlled release herbicide formulation was prepared by microencapsulation using interfacial polymerization technique. Methylene bisdiphenyl diisocynate (MDI) based polyuria as shell wall material containing mertribuzin herbicide as a core moiety has been prepared by an interfacial polycondensation reaction in emulsion globules between diisocyanate and ethylene diamine. [ABSTRACT FROM AUTHOR]

A greenhouse study was conducted in the Department of Agronomy and Plant Breeding, Mohaghega Ardabili, University of Ardabil, Iran during 2012 to determine the efficacy of 3 adjuvants (citogate, castor oil and canola oil) at concentrations of 0, 0.1 and 0.2 (%v/v) with mixture of metsulfuron methyl and sulfosulfuron (Total®) herbicide @ 4, 10, 20, 30 and 40 g. a.i to control littleseed canary grass (Phalaris minor Ritz.). Results showed that all adjuvants enhanced the efficacy of Total® in decreasing the dry weights of littleseed canary grass. Performance of herbicide increased with enhancing their concentrations against the tested plant. Measured ED50 and ED90 doses of Total® alone based on littleseed canary grass dry weight were 17.61 and 34.27 g a.i./ha, respectively. Whereas values for citogate 0.2 (%v/v), were 6.03 and 14.27 g a.i/ha, respectively. The addition of citogate and canola oil had the highest and lowest effect on Total® efficacy against littleseed canary grass, respectively, supporting the idea that this adjuvant solubilizes the cuticular waxes thus facilitating herbicide uptake. [ABSTRACT FROM AUTHOR]

The study was conducted during Kharif 2010-11 at Adaptive Research Farm, Gujranwala, Pakistan to evaluate butachlor orthosulfamuran and pretilachlor used 5 days after transplanting of rice as pre-emergence herbicides for controlling narrow, broad leaves and sedges type of weeds in transplanted rice. The experiment was laid out in RCBD comprising four treatments T1 (Control), T2 (Butachlor 2000 ml/ha) T3 (Orthosulfamuran 150g/ha) and T4 (Pretilachlor 1000 g/ha) with three replications. Statistically significant effect in yield was recorded in T2 (4.57t/ha) followed by T3 (4.21t/ha) and T4 (3.95t/ha) compared to T1 (2.97t/ha) during 2010. However significant effect in yield was recorded by T2 (4.37t/ha) followed by T3 (4.11t/ha) and T4 (3.81t/ha) compared to T1 (2.99t/ha) during 2011. The economic analysis of different weed control treatments depicted that maximum economic return was recorded in T2 (Rs.18664/ha) with CBR (1:1.73); during 2010-2011. It was concluded that orthosulfamuran 5DAT is most effective against all types of weeds in transplanted rice. [ABSTRACT FROM AUTHOR]

Alachlor, atrazine (broad-leaf herbicides), and chlorbromuron (photosynthesis inhibitor) have been used worldwide to control weeds in crops. Their extensive use have led to widespread contamination of soils, and water which has consequently led to increasing concern about the environmental fate of these substances, since these herbicides are persistent in the environment and exhibit relatively slow rate of decomposition. Several advanced oxidation processes have been used to degrade such bio-refractory organic contaminants present in wastewater. The Fenton process is classified among these processes and has been used for the removal of many hazardous organics from wastewater efficiently. This study reports the removal of alachlor, atrazine, and chlorbromuron from aqueous effluents by classical Fenton, electro-Fenton, peroxi-coagulation, and photoperoxi-coagulation processes in slightly acidic aqueous solutions. A UV lamp was used to assist the peroxi-coagulation process. Herbicide concentration decrease during the oxidation processes was followed by HPLC and chemical oxygen demand (COD) analyses. The reaction for the removal of these herbicides follows apparent-first-order kinetics. Photoperoxi-coagulation was better than electro-Fenton process. The use of UV-light irradiation during the herbicide elimination by peroxi-coagulation achieved total COD removal at 75 min for all the three herbicides treated. In the absence of UV-light irradiation, COD removals of 96, 97, and 93% were achieved for 83.3 mg/L alachlor, 62.0 mg/L of atrazine, and 35.0 mg/L of chlorbromuron, respectively. [ABSTRACT FROM PUBLISHER]

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Amicarbazone (AMZ) is an extensively used, broad-spectrum triazolinone herbicide. The literature is scarce regarding experimental data on AMZ photodegradation, whose fate in natural waters has not yet been investigated in detail. By combining laboratory experiments using isolated natural organic matter, literature data, and mathematical simulations, we investigated the sunlight-driven direct and indirect degradation of AMZ. We show that the reaction with hydroxyl radicals () is the main pathway leading to AMZ degradation, with measured second-order reaction rate constant ( kAMZ, OH) equal to 2.05×1010 L/mol·s. Simulations suggest that amicarbazone degradation is favored in shallow water bodies containing low dissolved organic carbon (DOC) and bicarbonate/carbonate concentrations, with herbicide half-life varying from about less than 1 day to more than 2 months. These values of t1/2 are upper limits since the reaction with 3CDOM* was not considered. Finally, the cross-effects of water depth/[DOC] are slightly influenced by nitrate/nitrite and bicarbonate/carbonate concentrations, depending on the pH range. [ABSTRACT FROM AUTHOR]

Glyphosate (GP) is an active substance of the most common group of herbicides, applied to large cultivation areas as well as small allotments, home and industrial greeneries, those along traffic routes and around public areas. GP is highly valued for its lack of direct risks to humans and animals or no tendency to bioaccumulate in trophic networks. Over the past four decades of its use, GP was found to be extremely effective. However, controversies over its applications have been growing; therefore, it is increasingly implied that its effects on the environment, living organisms and people residing in it should be verified. [ABSTRACT FROM AUTHOR]

A field investigation was carried out during winter season of 2011-12 and 2012-13 at IARI Regional Station. Karnal (Haryana) to evaluate the effect of pre and post emergence herbicides on weeds, seed yield and seed quality of garden pea cv. Pusa Pragati. The twelve treatments viz. imazethapyr 50, 75 and 100g ha-1 (20DAS), pendimethalin 0.75 and 1.50kg ha-1 (pre-emergence), trifluralin 1.00 and 1.50kg ha-1 (PPI), ready mixture of imazethapyr and imazamox 50,70 and 90g ha-1 (20DAS), hand weeding twice (20 and 45 DAS) and unweeded check were tested in randomized block design with three replications. The treatments hand weeding twice and imazethapyr @ 75g and lOOg ha-1 recorded significantly higher pods per plant, seeds per pod, pod filling, 100 seed weight and seed yield than other herbicidal treatments and unweedy check. These treatments also recorded lower weed dry weight and higher weed control efficiency than other treatments. It may be inferred from the present investigation that in addition to hand weeding twice, post emergence herbicide imazethapyr @ 75g ha-1 (20DAS) can be used effectively as an alternative for controlling weeds and in obtaining optimum seed yield and quality in garden pea under Karnal (Haryana) conditions. [ABSTRACT FROM AUTHOR]

The bioremediation of 2,4-dichlorophenoxyacetic acid (2,4-D) contaminated soil was studied in a roller slurry bioreactor operated under aerobic conditions. The performance of the roller slurry bioreactor was tested for different concentrations of 2,4-D in sandy loam soil (200, 300, and 500 mg/kg soil). Sewage sludge was used as an inexpensive source of microorganisms which is available in large quantities in wastewater treatment plants. The results show that all biodegradation experiments demonstrated a significant decrease in 2,4-D concentrations. Removal efficiencies of 100, 99, and 97% for the initial concentrations of 200, 300, and 500 mg 2,4-D/kg of soil were obtained after ten days, respectively. Abiotic conditions (reactor without microorganisms) were also performed to investigate the desorption efficiency of contaminants from soil to liquid phase. Different amendments as the surfactants sodium dodecyl sulfate, rhamnolipid and glass beads (with 10% load) were used in the roller slurry bioreactor to reduce the incubation time and to enhance the bioremediation efficiency. The results show that there was no reduction in the incubation time and no significant enhancement in the degradation efficiency of 2,4-D in soil for these amendments. [ABSTRACT FROM AUTHOR]

In this study, activated carbon was produced from the chips of two wood species, namely Ayous (Triplochiton schleroxylon) and Sapelli (Entandrophragma cylindricum) and characterized for its texture by scanning electron microscopy, granulometry using a master sizer, and the structure by determining the iodine and methylene blue indices. The obtained carbon was used to study the adsorption of paraquat in aqueous solution. Results from the characterization of carbon revealed that it consist essentially of micropores and mesopores, a tubular structure, and a fine coating of very small granules on the surface (Ayous) and elongated fibers (Sapelli). The adsorption kinetics of paraquat in solution followed a maximum exponential growth model with three stages: the first, which corresponds to an increase adsorption of the molecule on sites located on the outer surface of the carbon, the second phase, which correspond to the diffusion of the molecules on the internal pores, and the third constant phase corresponding to the adsorption equilibrium. The equilibrium time obtained was 10 min for Ayous with 87% of paraquat adsorbed and 20min for Sapelli with 90% of paraquat adsorbed. The biosorption kinetics of paraquat in the solution followed a pseudo-first order and intra-particle diffusion model. Result from the influence of paraquat concentration and mass of carbon showed that, an increase in concentration and mass of the adsorbent impel respectively in the amount of the paraquat molecule adsorbed. Change of solution pH does not affect the amount of paraquat adsorbed whatever the type of carbon. The adsorbed amounts of paraquat decreased (from 88 to 60 mg g−1) as the ionic strength increased from 5 × 10−3to 5 × 10−2 M. This study shows that activated carbon products obtained from Sapelli and Ayous wood chips, which are wastes released into the environment, can be used as low-cost biosorbents for the removal of organic micropollutants in drinking water. [ABSTRACT FROM PUBLISHER]

Several different alkoxycarbonyl-substituted 2-benzoxazolinone moieties have been incorporated into a tetrahydroisoindoline-1,3-dione scaffold to provide 25 compounds ( 1a- 1u and 2a- 2d). The structures of these compounds were confirmed by 1H and 13C NMR, HRMS and X-ray single-crystal diffraction. Some of these compounds ( 1g, 1h, 1j, 1k) exhibited excellent herbicidal activities against Abutilon theophrasti, Amaranthus retroflexus and Echinochloa crus-galli at a rate of 375 g AI·ha−1. Among them, compounds 1h and 1j displayed the best post-emergence herbicidal effect against Abutilon theophrasti with ED50 values of 1.8 and 5.3 g AI·ha−1, respectively, which are superior to that of the commercial acifluorfen (44.3 g AI·ha−1). Field trials demonstrated that compound 1h exhibited similar herbicidal activity to a high concentration atrazine, and found to be safer for maize than atrazine. The results of this study therefore show that compound 1h could potentially be used as a post-emergence herbicide for maize fields. [ABSTRACT FROM AUTHOR]

Fenoxaprop-P-ethyl is widely applied in rice ecosystem for weeding. A simple and accurate method for determination of fenoxaprop-P-ethyl and its metabolite fenoxaprop-P in paddy water, paddy soil, rice plants, husked rice, straw and rice hull was established by high performance liquid chromatography-tandem mass spectrometry ( HPLC-MS-MS). Recoveries of fenoxaprop-P-ethyl and fenoxaprop-P in these matrices at three spiking levels ranged from 75.1 to 102.8% with relative standard deviations ( RSDs) of 1.6 to 8.2%. The limits of detection ( LODs) of fenoxaprop-P-ethyl and fenoxaprop-P were 0.003 mg/kg. Fenoxaprop-P-ethyl dissipated rapidly to fenoxaprop-P in paddy water and soil during hours. The half-life of fenoxaprop-P-ethyl in rice plants was 1.26-1.41 days, and the half-life of fenoxaprop-P in paddy water, paddy soil and rice plants was 1.87-1.93, 1.61-2.31 and 1.82-1.93 days. The ultimate residues of fenoxaprop-P-ethyl and fenoxaprop-P in paddy soil, straw, rice hull and husked rice samples at harvest were not detectable or below 0.01 mg/kg. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing 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.)

The aim of this paper was the development and optimization of an electrochemical method for the degradation of two triketone herbicides, mesotrione, and sulcotrione, in a two-electrode undivided electrochemical cell equipped with commercially available, non-modified, electrode materials. The electrochemical parameters studied included five different electrode systems (Zr/Pt, Pd/Pt, C/Pt, Nb/Pt, and Ti/Pt), current densities (27.66, 55.33, ..., 110.66 mA · cm−2) and pH values (3, 7, and 9) in 0.05 M sodium sulfate as supporting electrolyte. The electrical energy consumption and chemical oxygen demand were calculated for optimal conditions. The degradation efficiency was determined by high performance liquid chromatography (HPLC) equipped with a diode array detector, while the degradation products for both pesticides were identified and compared by ultra-high performance liquid chromatography (UHPLC)-mass spectrometry. The results could lead to an accurate estimate of their effect on the environment. A real water sample was used to study the influence of organic matter on pesticide degradation. Based on the results obtained the electrochemical treatment could be used for the successful removal of triketone herbicides from contaminated water. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to find out a suitable and economical method of weed management in ajwain. The experiment was laid in randomized block design with three replications. Based on the two year study, it was found that besides weed free treatment, significantly higher plant height, number of primary, secondary branches, number of leaves, number of nodes and dry matter accumulation plant-1 at (60 DAS, 90 DAS and at harvest) were recorded with the pre-emergence application of oxadiargyl @75 g ha-1 + one hand weeding at 45 days after sowing (DAS) and pendimethalin @1 kg ha-1 + one hand weeding at 45 DAS. Yield attributes like number of umbels plant-1, number of umbellate pant-1, number of seeds umbel-1, umber of seed umbellate-1 and test weight as well as seed and straw yields of ajwain were also higher with the above two treatments. After weed free treatment, the lowest dry weight of weed at harvest, weed index and highest weed control efficiency were obtained with pre-emergence (PE) application of oxadiargyl @75 g ha-1 + one hand weeding at 45 DAS. The highest gross returns and net returns per hectare were obtained in weed free treatment. This was followed by pre-emergence application of oxadiargyl @75 g ha-1 + one hand weeding at 45 DAS, which recorded the highest B: C ratio (2.62). [ABSTRACT FROM AUTHOR]

Surfactants in herbicide formulations eventually enter soil and may disrupt various processes. Research examined effects on nutrient uptake in corn caused by surfactants, herbicides, and surfactant-herbicide combinations applied to silt loam and silty clay loam soils in the greenhouse. Surfactants evaluated were Activator 90, Agri-Dex, and Thrust; herbicides were glyphosate, atrazine, and bentazon. Corn was planted in fertilized soils with moisture content maintained for optimum growth. Foliage (V8 growth stage) was collected for elemental analyses. Nutrient uptake differed with soil texture. Nutrient uptake from silty clay loam was more affected by surfactants and/or herbicides than in silt loam. Potassium uptake was significantly (P= 0.05) decreased in silt loam only by Thrust but uptake of phosphorus (P), potassium (K) calcium (Ca), sulfur (S), copper (Cu), and zinc (Zn) decreased by ≤30% in silty clay loam treated with surfactants. Surfactants and/or herbicides may interact with soil texture to affect nutrient uptake. Long-term field studies to validate changes in nutrient uptake and grain yields after annual applications of surfactants plus herbicides are needed. [ABSTRACT FROM PUBLISHER]

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Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I + P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. [ABSTRACT FROM AUTHOR]

In this study, the leaching of 14 substituted phenylurea herbicides (PUHs) through disturbed soil columns packed with three different soils was investigated in order to determine their potential for groundwater pollution. Simultaneously, a series of experiments were conducted to demonstrate the effect of four different organic wastes (composted sheep manure (CSM), composted pine bark (CPB), spent coffee grounds (SCG) and coir (CR)) on their mobility. All herbicides, except difenoxuron, showed medium/high leachability through the unamended soils. In general, addition of agro-industrial and composted organic wastes at a rate of 10 % ( w/ w) increased the adsorption of PUHs and decreased their mobility in the soil, reducing their leaching. In all cases, the groundwater ubiquity score (GUS) index was calculated for each herbicide on the basis of its persistence (as t) and mobility (as K). The results obtained point to the interest in the use of agro-industrial and composted organic wastes in reducing the risk of groundwater pollution by pesticide drainage. [ABSTRACT FROM AUTHOR]

The sulphonylurea herbicide monosulphuron ester sodium (MES) was first used to induce male sterility in rapeseed (Brassica napus L.). Nearly 100% male sterility was achieved after a single treatment with 10 ml of 0.05-0.10 µg/ml MES solution per plant to the cultivars Zhongshuang No.9 and Zhongshuang No.11 at the uninucleate stage of the longest buds. No adverse effects on main agronomic traits and female fertility were observed. In the subsequent experiment, 48 out of 49 different accessions showed male sterility after spraying with 10 ml of 0.10 µg/ml MES solution per plant. Seven out of these 48 accessions were male sterile for the entire flowering period. Seed number per plant of these MES-treated plants was not significantly reduced compared to the controls. The hybridity was 95.5% in the case of seeds harvested from the ZS09 inbred line if sprayed twice with 10 ml of 0.10 µg/ml MES solution per plant and pollinated by the SH11 male line. These results suggest that MES is an efficient chemical hybridising agent for B. napus. [ABSTRACT FROM AUTHOR]

A method to determine residues of the three acid herbicides, 2,4,5-trichlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, and 3,6-dichloro-2-methoxybenzoic acid (dicamba), in tobacco using LC/MS/MS is presented. Because these herbicide residues in tobacco might exist in different forms (free acid, salt, and ester), tobacco samples were first pretreated by alkaline hydrolysis and then the pH was adjusted in order to convert the residues completely to their free acid forms. Dichloromethane extraction and dispersive SPE using C18 sorbent were carried out before LC/MS/MS analysis, and quantification was performed using the internal standard method. Linearity was good for all analytes (R² ≥ 0.999) in the concentration range of 0.02 to 0.5 mg/kg. LODs were below 0.05 mg/kg. Recoveries ranged from 80.4 to 93.5%, and RSD was below 10%. This simple, efficient, and sensitive method can be applied to the determination of residues of the three acid herbicides in tobacco. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing 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.)

The effects of environmental parameters on bioherbicidal activity of the bacteriumXanthomonas campestris, against glyphosate-resistant and – susceptibleConyza canadensis(horseweed), were studied under greenhouse conditions. Rosette leaf-stage plants were more susceptible than older plants, and increasing inoculum from 105to 109cells/mL caused significantly greater plant mortality and biomass reduction of plants in both the rosette and bolting growth stages. A dew period at 25°C was required to cause an 80% and 60% mortality of plants in the rosette and bolting growth stages, respectively. Results indicate thatX. campestriscan infect and kill horseweed, demonstrating its bioherbicidal potential. [ABSTRACT FROM PUBLISHER]

Herbicides and pesticides are being used worldwide for protection of crops from weeds and insects in agricultural fields. Aim of the present study was to analyze the mitigation of cytotoxic effects of endosulphan by α-tocopherol in kidneys of Cyprinus carpio in vitro. Cyprinus carpio kidney was cut into smaller pieces (1mm3) and divided into two experimental groups. One experimental group was exposed to endosulphan (100 nmolml-1) and second with endosulphan supplemented with -tocopherol (100 μmol L-1). After exposure of endosulphan, enlarged haemorrhage in the renal tubules, narrowing of tubular lumen, and pycnosis in nuclei were observed. Supplementation of á-tocopherol along with endosulphan exposure, no significant change in histoarchitecture of kidney was noticed after 1h. After 8 hours vacuoles in cytoplasm was reported in number of cells however these degenerative changes were not so prominent as observed in endosulphan exposed kidney tissue demonstrating that vitamin E supplementation provides mitigation in endosulphan induced renal toxicity. [ABSTRACT FROM AUTHOR]

Roundup, a glyphosate-based herbicide is one of the most commonly used herbicides. Indiscriminate use of this herbicide might have impact on non-target species including humans. The objective of this study was to determine the sub-acute effect of Roundup on malondialdehyde (MDA) and lipids of rat brain. Thirty two adult male rats (Wistar strain) divided into 4 groups of 8 rats each, were used for this study. Group one served as the control and was given distilled water. The test groups T3, T4 and T6 were given graded doses: 300, 400 and 600 mg Roundup Kg-1body wt respectively, orally for 8 days. At the end of the treatment period the brain was excised. Alterations in the integrity of brain cell membrane was determined by the estimation of the MDA level, total cholesterol (CHOL), total phospholipid (TPL), phosphatidylcholine (PC) phosphtidylethanolamine (PE), PC/PE and TPL/CHOL molar ratios. Results showed that there were significant (p<0.05) reductions in MDA and cholesterol levels of all the Roundupexposed rats relative to the control. However the MDA levels were elevated in the liver and kidney. The TPL/CHOL molar ratios were normal in the T4 and T6-treatment groups while the PC/PE molar ratios were significantly (p<0.05) increased relative to the control. The pattern observed for the T3-treatment group was opposite that observed for the T4 and T6-treatment groups. This study suggests that the rearrangement in the lipid composition of the test groups might be an adaptive mechanism for the maintenance of constant bilayer fluidity and consequently brain cell homeostasis. [ABSTRACT FROM AUTHOR]

Laboratory and greenhouse studies were conducted to determine the absorption, translocation, dose response, efficacy, and effects on biomass of the herbicide diclosulam on bristly starbur ( Acanthospermum hispidum DC.) In laboratory experiments, 14C-diclosulam absorption and translocation was evaluated in bristly starbur. Greenhouse studies determined bristly starbur growth response to postemergence applied diclosulam at 0, 0.2, 0.4, 0.8, 1.6, 3.3, and 6.5 g ai/ha. Bristly starbur seed were collected from two Georgia locations, hand cleaned, and grown in the greenhouse. Bristly starbur plants were then foliar treated with diclosulam when plants were in the 4 to 6 leaf stage of growth. 14C-diclosulam was applied to a single non-treated, most fully developed bristly starbur adaxial leaf, after the rest of the plant was foliar treated with 0.8 g ai/ha of diclosulam. At 24 and 48 hours after treatment, 14C-diclosulam was translocated acropetally in bristly starbur to the plant apex, with little to no movement to the lower plant parts including lower leaves, stem and roots. For the dose response studies, bristly starbur growth reduction dry weight (GR50) and efficacy (I50) for diclosulam ranged from 0.95 to 0.92 g ai/ha, respectively. Based on these data, bristly starbur susceptibility to diclosulam was due to its translocation to apical growing points within 24 to 48 hours where acetoacetate synthase (ALS) inhibition occurred resulting in eventual plant death. While bristly starbur is controlled with diclosulam rates below the standard use rate of other weeds, the standard field rates in combination with other herbicide mechanisms of action will continue to be recommended to peanut growers to reduce the potential for bristly starbur ALS resistance selection. [ABSTRACT FROM AUTHOR]