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Copyright of Iraq Journal of Market Research & Consumer Protection / Al-Mağallaẗ al-ʿIrāqiyyaẗ li-Buḥūṯ al-Sūq wa-Ḥimāyaẗ al-Mustahlik is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Glyphosate-resistant sourgrass is difficult to control, particularly when perennial, and strategies that improve the control efficiency against this grass and preserve the useful life of graminicides are warranted. Therefore, the present study aimed to answer the following questions: (i) Does fractionating the doses of ACCase inhibitors improve the control of perennial sourgrass? (ii) Does alternating the chemical groups cyclohexanediones (DIMs) and aryloxyphenoxypropanoates (FOPs) improve the control of perennial sourgrass, and does the order of their application affect sourgrass control efficiency? (iii) Does the addition of glyphosate to ACCase inhibitors improve to the control of perennial sourgrass resistant to 5-enol-pyruvyl-shiquime-3-phosphate synthase inhibitors? Two field experiments (I and II) were performed in 2018 and repeated in 2019. In experiment I, the treatments included a single or fractional application clethodim + quizalofop-P-ethyl (216 + 108 g a.i. ha-1), clethodim (216 g a.i. ha-1), and quizalofop-P-tefuryl (108 g a.i. ha-1), applied in the order of clethodim followed by quizalofop-P-tefuryl and vice versa, as well as a control treatment. In experiment II, the treatments included a single or fractional application of clethodim + quizalofop-P-ethyl (216 + 108 g a.i. ha-1) and clethodim (108 g a.i. ha-1), isolated or associated with glyphosate, as well as a control treatment. In both experiments, the interval between the fractional applications was 7 days. Percentage of control, number of tillers per plant, and height of sourgrass plants were determined. Compared with the unfractionated application, the fractionation of clethodim + quizalofop-P-ethyl and clethodim increased control by respectively 20-24 and 25-30%. Fractionated clethodim has greate control, and less regrowth and height of the sourgrass plants. The order of application of the chemical groups FOPs and DIMs affected control efficiency, and better results were obtained with the application of quizalofop-P-tefuryl followed by clethodim. The addition of glyphosate potentiates the action of graminicides, particularly when fractionated, even on resistant sourgrass, with a 26% increase in efficiency and resulting in satisfactory control ( > 80%).

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Nissan Chemical Europe S.A.S. submitted a request to the competent national authority in Finland to modify the existing maximum residue level (MRL) for quizalofop in caraway to accommodate the intended NEU use of quizalop‐P‐ethyl for this commodity. The data submitted in support of the request were found to be sufficient to derive an MRL proposal for caraway. Adequate analytical methods for enforcement are available to control the residues of quizalofop, resulting from the use of quizalofop‐P‐ethyl, on the commodity 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 quizalofop‐P‐ethyl according to the reported agricultural practice is unlikely to present a risk to consumer health. [ABSTRACT FROM AUTHOR]

The occurrence of voluntary corn has been common in Brazilian crops, due to the adoption of a succession of soybean and corn crops resistant to glyphosate. The aim of this work was to evaluate the control of voluntary corn using different doses of acetyl-CoA carboxylase (ACCase) inhibitors herbicides at different phenological stages. The experiment was carried out in a greenhouse, in a completely randomized design. The treatments were organized in a factorial scheme (3x7x2), with three herbicides (clethodim, quizalofop and clethodim + quizalofop), applied in seven doses [0; 25; 50; 100; 200; 400 and 800 mL of commercial product (C.P.) ha-1], at two phenological stages (V3 and V6). Visual control assessments were carried out at 14, 21 and 28 days after application of treatments (DAT) and shoot dry mass (SDM) at 28 DAT. The data were submitted to analysis of variance and to complementary analysis by regression adjustment. For all herbicides, the control of voluntary RR corn was greater at V3 stage, requiring lower doses compared to V6. The total control of voluntary corn plants at V3 was obtained with doses of 25 mL C.P. ha-1 for all herbicides evaluated. For V6 application, 400 mL C.P. ha-1 of clethodim and 100 mL C.P. ha-1 of quizalofop and clethodim + quizalofop were necessary to achieve 100% control. Thus, clethodim was more sensitive to advancing corn growth, compared to others herbicides, requiring higher doses to achieve complete control of volunteer corn.

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Nissan Chemical Europe S.A.S. submitted a request to the competent national authority in Finland to modify the existing maximum residue level (MRL) for quizalofop in caraway to accommodate the intended NEU use of quizalop‐P‐ethyl for this commodity. The data submitted in support of the request were found to be sufficient to derive an MRL proposal for caraway. Adequate analytical methods for enforcement are available to control the residues of quizalofop, resulting from the use of quizalofop‐P‐ethyl, on the commodity 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 quizalofop‐P‐ethyl according to the reported agricultural practice is unlikely to present a risk to consumer health.

Chloris elata is an important weed for grain and sugarcane crops. In addition to its aggressiveness, it may show resistance to glyphosate herbicide. In this context, the aim of this study was to assess the effectiveness of glyphosate formulations, isolated or in association with ACCase inhibitors, in controlling C. elata (putatively resistant to glyphosate) at different developmental stages. Four experiments were conducted in a completely randomized design. Treatments consisted of glyphosate application under different formulations with ACCase inhibitors, isolated or in mixtures. Applications were carried out at the stages of four fully expanded leaves in Experiment I, four tillers in Experiment II, and at regrowth of the four-tiller plants in Experiments III and IV. Applications of glyphosate isopropylamine salt associated with sethoxydim or clethodim showed to be among the best treatments in Experiments I, II, and III, presenting control scores equal to or greater than 90%. However, not even these treatments could provide successful control in Experiment IV. Moreover, and regardless of the formulation, isolated glyphosate, showed 85% (Experiment III) and 50% (Experiment IV) maximum controls. Associations between glyphosate and ACCase-inhibiting herbicides showed to be effective in controlling C. elata, especially at early developmental stages. In general, isolated herbicides provided lower percentages of control, as well as higher values of dry matter. Sole herbicide applications were not effective in controlling C. elata (putatively resistant to glyphosate), regardless of the developmental stage. Highlights: Mixtures between glyphosate and ACCase-inhibiting have been shown to be effective in C. elata control, especially in the early development stages. Isolated herbicide applications were not effective in controlling C. elata, regardless of the development stage. Mixtures between glyphosate and ACCase-inhibiting is more important in the control than the glyphosate formulation or ACCase-inhibiting used.

An on-farm trial to evaluate Oxyflurofen and Quizalofop ethyl weedicides for weeds control on Onion (Allium cepa L.) was undertaken during Rabi 2015-16, 2016-17 and 2017-18 at farmer fields in south west district of Najafgarh, New Delhi. The study the herbicidal treatment combination were taken of Oxyfluorfen @ 150 ml/ha + Quizalofopethyl @ 750 ml/ha foliar spray 35 days after transplanting recorded lower weed density (39.66/m²), dry matter weight of weeds (42.22 g/m²) and higher weed control efficiency (77.61%), followed by treatment1 farmers' practice (Pendimethalin + one hand- weeding) 48.21%. The application of Oxyfluorfen @ 150ml/ha + Quizalofopethyl @ 750 ml/ha foliar spray 35 days DAT proved to be most effective weed control treatment, recording highest bulb yield (277.44 q/ ha), net return (171, 952/ha) and B:C ratio (3.77), followed by farmers' practice (252.22 q/ ha), net return (129276/ha) and B:C ratio (3.01). The increased returns as a result of increased quality bulb yield of onion with pre-post herbicides applications showed significant effect with more appreciation. [ABSTRACT FROM AUTHOR]

Chloris elata is an important weed for grain and sugarcane crops. In addition to its aggressiveness, it may show resistance to glyphosate herbicide. In this context, the aim of this study was to assess the effectiveness of glyphosate formulations, isolated or in association with ACCase inhibitors, in controlling C. elata (putatively resistant to glyphosate) at different developmental stages. Four experiments were conducted in a completely randomized design. Treatments consisted of glyphosate application under different formulations with ACCase inhibitors, isolated or in mixtures. Applications were carried out at the stages of four fully expanded leaves in Experiment I, four tillers in Experiment II, and at regrowth of the four-tiller plants in Experiments III and IV. Applications of glyphosate isopropylamine salt associated with sethoxydim or clethodim showed to be among the best treatments in Experiments I, II, and III, presenting control scores equal to or greater than 90%. However, not even these treatments could provide successful control in Experiment IV. Moreover, and regardless of the formulation, isolated glyphosate, showed 85% (Experiment III) and 50% (Experiment IV) maximum controls. Associations between glyphosate and ACCase-inhibiting herbicides showed to be effective in controlling C. elata, especially at early developmental stages. In general, isolated herbicides provided lower percentages of control, as well as higher values of dry matter. Sole herbicide applications were not effective in controlling C. elata (putatively resistant to glyphosate), regardless of the developmental stage. [ABSTRACT FROM AUTHOR]

A method for simultaneous quantitation of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in potato plant, soil and potato tuber samples was established. The mean recoveries of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in different matrices spiked with them were 81.4%–101.1%, 76.1%–99.0% and 77.4%–106.4% with relative standard deviations (RSDs) of 2.7%–13.3%, 0.9%–5.5%, 1.7%–11.3%, respectively. The open-field trials in China were conducted in potato cultivation system of Changchun and Jinan. The results indicated that the half-lives of rimsulfuron and quizalofop-P-ethyl were 0.04–13.1 days. The residues of quizalofop-P during the harvest time in Jinan soil were < 0.01–0.044 mg kg−1, while there was no residue of target herbicides detected in all other samples. The risk assessment results demonstrated that the risk quotients (RQs) of rimsulfuron and quizalofop-P-ethyl were 7.857 × 10−5 and 8.730 × 10−3, respectively, which exhibited an acceptable dietary risk to Chinese consumers. [ABSTRACT FROM AUTHOR]

Pesticides with acidic properties, such as 2,4-D, 2,4-DB, acibenzolar-S-methyl, clopyralid, dichlorprop, haloxyfop, fluazifop, fluroxypyr, mecoprop, MCPA, MCPB and quizalofop, could pose health risks, because of their neurotoxicant potentials and adverse effects on endocrine and reproduction systems. Since the use of these compounds are still permitted in several countries, their residues on fresh agricultural commodities should be monitored with proper analysis methods. Unfortunately, determination of their residues is difficult due to their tendencies to form various conjugates with matrix components. Although the QuEChERS method is commonly used for extraction of pesticide residues on fresh vegetables and fruits [1], it is not appropriate for reliable and accurate analysis of the acidic pesticides due to transform their several esters and conjugates [2]. To overcome the drawbacks of QuEChERS method during the analysis of acidic pesticides, addition of a hydrolysis step in sample preparation may be taken into consideration [2,3]. The aim of the current study was to optimize and validate an LC-MS/MS method for the detection of acidic pesticides on fresh foods using alkaline hydrolysis of their esters and conjugates. The multi-residue analysis of 12 active compounds was found compatible with the SANTE/11312/2021 Guidelines. [4]. The quality of the developed method was also testified by both TestQual and QS proficiency tests. The scope of these proficiency tests is the evaluation of the performance of laboratories for the determination of pesticide residues on foods and they provide information to demonstrate the quality of the analysis. Thus, our method was found as reliable and effective to use for the detection of acidic pesticides in fresh foods using LC-MS/MS. In the current method, these pesticides were extracted by using a modified QuEChERS method (AOAC 2007.01) involving the addition of acetonitrile and NaOH together to the sample tube for simultaneous extraction and hydrolysis. The tubes were shaken for 30 min in water bath set at 40°C and then the reaction was neutralized by the addition of H2SO4. After the addition of buffer-salt mixture, the sample was immediately shaken vigorously and centrifuged. Lastly, the supernatant was transferred to vials and tested with LC-MS/MS. PSA-clean up step is not performed in the method. This study was funded with as a research project (grant number ULUTEK STB079417) by Perla Fruit Company. [ABSTRACT FROM AUTHOR]

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Adama Agan Ltd submitted a request to the competent national authority in Italy to modify the existing maximum residue levels (MRLs) for propaquizafop/quizalofop in lettuces and salad plants to accommodate the intended SEU use of propaquizafop. The data submitted in support of the request were found to be sufficient to derive MRL proposals of 0.15 mg/kg for the intended SEU use of propaquizafop for the crops belonging to the crop group of lettuces and salad plants. The MRL proposals are expressed for a common residue definition that covers quizalofop and propaquizafop. Since the EU MRL is set at a higher level of 0.20 mg/kg, no modification of the MRL is currently required for the intended use. Adequate analytical methods for enforcement are available to control the residues of propaquizafop, expressed as quizalofop, in plant matrices under consideration. Based on the risk assessment results, EFSA concluded that the long‐term and short‐term intake of residues occurring in food from the existing uses of quizalofop‐P‐ethyl, quizalofop‐P‐tefuryl and propaquizafop and from the intended use of propaquizafop on lettuces and other salad plants, is unlikely to present a risk to consumer health.

Exposure to endocrine disrupting chemicals is an established risk factor for obesity. The most commonly used pesticide active ingredients have never been tested in an adipogenesis assay. We tested for the first time the potential of glyphosate, 2, 4-dichlorophenoxyacetic acid, dicamba, mesotrione, isoxaflutole, and quizalofop-p-ethyl (QpE) to induce lipid accumulation in murine 3T3-L1 adipocytes. Only QpE caused a dose-dependent statistically significant triglyceride accumulation from a concentration of 5 up to 100 µM. The QpE commercial formulation Targa Super was 100 times more cytotoxic than QpE alone. Neither the estrogen receptor antagonist ICI 182, 780 nor the glucocorticoid receptor antagonist RU486 was able to block the QpE-induced lipid accumulation. RNAseq analysis of 3T3-L1 adipocytes exposed to QpE suggests that this compound exerts its lipid accumulation effects via a peroxisome proliferator-activated receptor gamma (PPARγ)-mediated pathway, a nuclear receptor whose modulation influences lipid metabolism. QpE was further shown to be active in a PPARγ reporter gene assay at 100 µM, reaching 4% of the maximal response produced by rosiglitazone, which acts as a positive control. This indicates that lipid accumulation induced by QpE is only in part caused by PPARγ activation. The lipid accumulation capability of QpE we observe suggest that this pesticide, whose use is likely to increase in coming years may have a hitherto unsuspected obesogenic property. [ABSTRACT FROM AUTHOR]

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]

Weeds directly affect the tobacco's yield and quality by reducing it, because they are tobacco's competitors when it comes to food and space, they hinder the execution of work operations and host a large number of pests and pathogens - microorganisms that transmit various diseases. In addition to herbicides that are being used before transplanting tobacco (pendimetalin, klomazon), the herbicide quizalofop is used in tobacco vegetation. The purpose of the study was to check its effectiveness in the control of grass weeds in tobacco. The tests were performed on tobacco that is largely affected by the fibrous weed cockspur or common barnyard millet - Echinochloa crus-galli, for which the herbicide Leopard 5 EC with an active substance Quizalofop-p-ethyl 50 g/l was used at a dose of 2 l/ha. Before the treatment, the average number of weeds per 1 m² was 1477.33 with a weight of the green mass of 3728.00 g. Ten days after treatment, there were 1306,66 weeds of 1 m², with a total weight of 1050.66 g, and 30 days after treatment the weeds were completely dried, without the emergence of phytotoxicity in tobacco. The effectiveness from the use of the herbicide Leopard 5 EC for control of this weed in tobacco, was 71.93%. It can also be applied in the control of other types of grass weeds during vegetation after transplanting tobacco in the field. [ABSTRACT FROM AUTHOR]

Post-emergence herbicides are useful for managing weeds in soybean fields. Use of post-emergence herbicide(s) is increasing in India because of the ease of use and control of broad spectrum of weeds. As soybean is a rainy season crop in India, weed control remains an important concern for soybean farmers. An experiment was laid out at Research Farm of Punjab Agricultural University, Ludhiana to study effect of different herbicides for control of grass weeds in soybean. Treatments comprised of post-emergence application of quizalofop 25, 37.5 and 50 g/ha, fenoxaprop 100 g/ha, weed free and unweeded control. Phyto-toxic evaluation of herbicides was carried out on succeeding wheat crop. Quizalofop 37.5-50 g/ha significantly reduced weed density and biomass of grass weeds compared to weedy check. Quizalofop 50 g/ha gave complete control (100%) of Dactyloctenium aegyptium, Digitaria sanguinalis, Acrachne racemosa and Eragrostis spp. till 40 days and > 85% till 80 days after treatment. Quizalopfop 50 g/ha recorded soybean seed yield and yield attributes similar to that of weed free check; it gave highest B:C (2.61) and net returns ($660/ha) All weed control treatments provided higher soybean seed yield compared to unweeded control. Quizalofop at all doses was safe to succeeding wheat crop. [ABSTRACT FROM AUTHOR]

Abstract Effective grass weed control in rice is becoming more difficult due to herbicide resistance. To combat weed resistance a new non-GMO resistant rice is under development. Quizalofop, an acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicide, can be applied over-the-top of quizalofop-resistant rice for selective grass control. Due to the absence of broadleaf weed control from this herbicide, other herbicides will be needed to achieve control of a diverse weed spectrum. Antagonism often occurs when mixing ACCase-inhibiting herbicides with other herbicides; thus, two experiments were conducted to evaluate quizalofop in tank-mixes with common rice herbicides having either grass or broadleaf activity. Both greenhouse experiments were a two-factor factorial where factor-A was quizalofop rate and factor-B was tank-mix partner. The first experiment contained tank-mix partners for grass control with some treatments having activity on broadleaf species as well. The second experiment contained tank-mix partners that when applied alone are not effective in controlling grass weeds. The first experiment included labeled rates of clomazone, pendimethalin, thiobencarb, quinclorac, propanil, imazethapyr, bispyribac, penoxsulam, cyhalofop, and fenoxaprop in tank-mixes with quizalofop at 0 or 80 g ai ha−1 on common grass weeds found in rice production. The second experiment included labeled rates of triclopyr, acifluorefen, carfentrazone, salfufenacil, halosulfuron, halosulfuron + thifensulfuron, bentazon, or 2,4-D amine in tank-mixes with quizalofop at 0, 80, or 160 g ai ha−1. Tank-mix interactions for percent control or biomass reduction were evaluated using Colby's method. Overall, quizalofop alone provided effective control of all grass species evaluated (>90%) in both experiments, except for ACCase-resistant Amazon sprangletop. When quizalofop was tank-mixed with other herbicides, antagonism was observed for various combinations on multiple grass weeds. The acetolactate synthase (ALS)-inhibiting herbicides consistently antagonized quizalofop in terms of grass weed control and biomass reduction. Likewise, the addition of propanil to quizalofop antagonized the graminicide based on multiple grass species evaluated. Similarly, the auxinic herbicides antagonized quizalofop, with 2,4-D being the most consistently antagonistic tank-mix partner, resulting in reduced control of all grass weeds evaluated compared to quizalofop alone. Overall, the results indicate caution should be taken before tank-mixing quizalofop with other rice herbicides, and ultimately, separate applications may be needed when a diverse spectrum of grasses, broadleaves, and/or sedges are present in a rice field. [ABSTRACT FROM AUTHOR]

Banded herbicide applications with hooded field sprayers (HFS) provide safer applications in many crops. The aim of this paper is to show the effectiveness and safeness of selective and nonselective herbicide applications in a conventional sunflower production system (CSPS) using a combined hooded field sprayer (CHFS). Glyphosate interrow and aclonifen or quizalofop-P-ethyl intrarow were applied in fields cropped with nonglyphosate-resistant sunflower varieties in Ankara, Tekirdağ, and Tokat Provinces of Turkey in 2015 and 2016. In Ankara and Tekirdağ, glyphosate caused limited injury to sunflower at 28 days after treatment (DAT), and aclonifen created transient phytotoxicity in 2015. Glyphosate was applied with aclonifen at 1.44 + 0.75 and 2.88 + 0.75 kg ai ha-1 or quizalofop-P-ethyl 1.44 + 0.05 and 2.88 + 0.05 kg ai ha-1 using band application units of CHFS together. Aclonifen and quizalofop-P-ethyl were also used at 0.75 and 0.05 kg ai ha-1, respectively, using the conventional application unit of CHFS. Glyphosate + aclonifen (1.44 + 0.75 and 2.88 + 0.75 kg ai ha-1) provided higher weed control and sunflower seed yield compared with the other treatments. Aclonifen (0.75 kg ai ha-1) controlled many competitive arable weeds and increased sunflower seed yield, except in Tokat in 2016, where common cocklebur was present in the field, which is not in the range of aclonifen. Weed control by glyphosate + quizalofop-P-ethyl (1.44 + 0.05 and 2.88 + 0.05 kg ai ha-1) was limited because broadleaf weeds covered the sunflower fields where the trials were conducted. Quizalofop-P-ethyl (0.05 kg ai ha-1) alone and untreated control were associated with the lowest sunflower seed yield. It is concluded that banded application of glyphosate is safe and effective in sunflowers. Applying glyphosate with aclonifen and quizalofop-P-ethyl with CHFS helps to save time and money, and mitigate CO2 emission. [ABSTRACT FROM AUTHOR]

A degradation study of quizalofop-p and its commercial products (quizalofop-p-ethyl, quizalofop-p-tefuryl and propaquizafop) in water samples has been performed using ultra high-performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). CHHQ (dihydroxychloroquinoxalin), CHQ (6-chloroquinoxalin-2-ol) and PPA ((R)-2-(4-hydroxyphenoxy)propionicacid) were the main metabolites of this active substance (quizalofop-p) in water. The degradation of the parent compound has been monitored in distilled water. Several commercial products (Panarex®, Master-D® and Dixon®) were used to evaluate the degradation of the target compounds into their metabolites. The concentration of the main active substances (quizalofop-p-tefuryl, quizalofop-p-ethyl and propaquizafop) decreased during the degradation studies, whereas the concentration of quizalofop-p increased. DT 50 of the main active substances ranged from 10 days to 70 days for most of the analytes, so it can be concluded that compounds are medium-high persistent in this matrix. Metabolites, such as PPA, CHHQ and CHQ, were detected in water samples after 7 days of the application of the commercial products at concentrations higher than their limits of quantification (> 0.1 µg/L). CHQ was detected at 1400 µg/L after 75 days of the application of quizalofop-p-ethyl commercial product. CHHQ and CHQ were found at the highest concentrations at 7–45 days after the application of quizalofop-p-tefuryl, whereas PPA was detected at higher concentrations (up to 5.37 µg/L) in propaquizafop samples. [ABSTRACT FROM AUTHOR]

The objective of this study was to enhance biomass and lipid productivity in Chlorella sp. isolate 6-4 by inducing mutagenesis with two growth inhibitors: the herbicide quizalofop-P-ethyl, a known inhibitor of acetyl-CoA carboxylase (ACCase) activity, and chemical mutagen, ethyl methanesulfonate (EMS), at different concentrations and length of times. The induced-mutagenized microalgae were screened on selective medium containing 10-100 µM quizalofop. The biomass yield, biomass productivity, lipid content, and lipid productivity of mutagenized microalgae were determined. The result showed that 100-200 mM EMS concentrations and 30 min incubation time were the most effective. Biomass yield and biomass productivity of the mutagenized microalgae E50-30-40, E100-60-40, and E100-30-60 were statistically significant higher than those of the wild type. The mutagenized microalgae E100-30-60 showed that the highest biomass yield and biomass productivity were 111 and 110% higher than the wild type, respectively (p < 0.01). Lipid content and lipid productivity of the mutagenized microalgae E200-30-40 were 59 and 53% significantly higher than the wild type, respectively. It should be noted that biomass productivity of the mutagenized microalgae E200-30-40 was not significantly different from E100-30-60, meaning that this microalga strain exhibited highest both biomass and lipid productivity. These results indicated that inducing mutagenesis by EMS subsequently screening by herbicide could lead to enhance biomass and lipid accumulation. Therefore, this methodology could be used for improvement microalgae for biofuel production. [ABSTRACT FROM AUTHOR]

Due to the ongoing evolution of herbicide-resistant weeds, new technologies are needed to maintain effective levels of control. A new rice variety that will be resistant to quizalofop, an acetyl coenzyme A carboxylase- (ACCase-) inhibiting herbicide, is currently under development. With the anticipated launch of this technology in 2018, multiple experiments were conducted to determine effectiveness of the quizalofop-resistant rice system for common grass weed species found in Arkansas rice production. One hundred and twenty-six barnyardgrass populations were collected across Arkansas and treated with quizalofop at 80 g ai ha−1 to determine a baseline of response. All populations evaluated were effectively controlled (≥92%) by quizalofop, with only 13 populations resulting in lower than 98% control. A greenhouse and field trial were conducted to compare efficacy of quizalofop to currently labeled rice graminicides for control of common rice grass weeds. Results from the greenhouse experiment showed that quizalofop treatments resulted in greater efficacy of common grass weeds compared to cyhalofop or fenoxaprop. This was especially apparent at the larger grass growth stages. A field experiment conducted compared season-long weed control programs of quizalofop to fenoxaprop and cyhalofop. The quizalofop-containing treatments were no better than fenoxaprop and cyhalofop for barnyardgrass and broadleaf signalgrass control. Barnyardgrass and broadleaf signalgrass control were greater than 96% for all herbicide treatments. An additional field experiment was conducted to determine the best rate structure for sequential applications of quizalofop in rice. Sequential applications of quizalofop at 120 g ha−1 followed by 120 g ha−1 two weeks later resulted in the highest barnyardgrass and broadleaf signalgrass control. Likewise, applying the full seasonal use rate of 240 g ha−1 of quizalofop resulted in greater control compared to 200 and 160 g ha−1. Results from this research indicate a strong benefit from quizalofop use in rice. [ABSTRACT FROM AUTHOR]

Microalgae can synthesize and accumulate lipid upon abiotic stresses such as high light (HL) and nitrogen deficiency (ND). In this work, HL and ND were applied to the oleaginous alga Nannochloropsis salina, individually or in combination, in order to investigate the transcriptional regulation on lipid metabolism. An impaired cell growth was observed under all three stress conditions, with HL + ND leading to the lowest biomass concentration. HL + ND gave rise to the greatest total lipid content (46.5% dry weight), 64% higher than the control. By contrast, the highest lipid productivity was achieved under HL condition. Transcriptional analyses using quantitative real-time PCR suggested that the augmented accumulation of lipids including triacylglycerol (TAG) upon stresses correlated with the upregulation of pyruvate dehydrogenase complex, diacylglycerol acyltransferase, malic enzyme, and glucose-6-phosphate dehydrogenase and the downregulation of pyruvate dehydrogenase kinase, acetyl-CoA carboxylase (ACCase), and fatty acid elongase. The presence of Quizalofop, an inhibitor of ACCase, caused a considerable decline in TAG accumulation, yet having little effect on membrane lipids. Possible carbon metabolic pathways related to TAG biosynthesis are proposed. Our results facilitate the understanding of TAG accumulation and its transcriptional regulation and provide implications into future genetic engineering for improving lipid production by N. salina. [ABSTRACT FROM AUTHOR]

BACKGROUND Provisia™ rice (PV), a non-genetically engineered (GE) quizalofop-resistant rice, will provide growers with an additional option for weed management to use in conjunction with Clearfield® rice (CL) production. Modeling compared the impact of stacking resistance traits versus single traits in rice on introgression of the resistance trait to weedy rice (also called red rice). Common weed management practices were applied to 2-, 3- and 4-year crop rotations, and resistant and multiple-resistant weedy rice seeds, seedlings and mature plants were tracked for 15 years. RESULTS Two-year crop rotations resulted in resistant weedy rice after 2 years with abundant populations (exceeding 0.4 weedy rice plants m-2) occurring after 7 years. When stacked trait rice was rotated with soybeans in a 3-year rotation and with soybeans and CL in a 4-year rotation, multiple-resistance occurred after 2-5 years with abundant populations present in 4-9 years. When CL rice, PV rice, and soybeans were used in 3- and 4-year rotations, the median time of first appearance of multiple-resistance was 7-11 years and reached abundant levels in 10-15 years. CONCLUSION Maintaining separate CL and PV rice systems, in rotation with other crops and herbicides, minimized the evolution of multiple herbicide-resistant weedy rice through gene flow compared to stacking herbicide resistance traits. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A comprehensive degradation study of quizalofop-p, quizalofop-p-ethyl, quizalofop-p-tefuryl and propaquizafop in soil samples have been firstly performed using ultra high performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). Thus, metabolites or degradation products, such as CHHQ (dihydroxychloroquinoxalin), CHQ (6-chloroquinoxalin-2-ol), PPA (( R )-2-(4-hydroxyphenoxy)propionic acid) and 2,3-dihydroxyquinoxaline were also monitored. An extraction procedure based on QuEChERS procedure was used. Acidified water (0.1 M hydrochloric acid) and acidified acetonitrile (1% acetic acid, (v/v)) were used as extraction solvents, and magnesium sulfate and sodium chloride were used as salts. Dispersive solid phase extraction with C 18 as sorbent, was needed as a clean-up step. Several commercial products (Panarex®, Master-D® and Dixon®) were used to evaluate the degradation of the target compounds into their metabolites. The concentration of the main active substances (quizalofop-p-tefuryl, quizalofop-p-ethyl and propaquizafop) decreased during the degradation studies, whereas the concentration of quizalofop-p increased. Dissipation rates of half-live of quizalofop-p were also evaluated, and it was observed that this compound is easily degraded, obtaining values lower than 1 day. Taking into account that quizalofop-p is the R enantiomer of quizalofop, a chiral separation was performed by liquid chromatography coupled to tandem mass spectrometry, concluding that in samples containing quizalofop-p-tefuryl, there was a 15% contribution from the S enantiomer and a 85% contribution from the R enantiomer. Metabolites such as PPA, CHHQ and CHQ were detected in soil samples after 15 days of application commercial product at concentrations between the limits of detection (LOD) and the limits of quantification (LOQ). CHQ and CHHQ were detected at concentrations higher than the LOQ in samples after 50 and 80 days of application, with their concentration increasing during this time up to 500%. [ABSTRACT FROM AUTHOR]

According to Article 12 of Regulation (EC) No 396/2005, EFSA has reviewed the maximum residue levels (MRLs) currently established at European level for the pesticide active substance quizalofop-Pethyl, quizalofop-P-tefuryl and propaquizafop. To assess the occurrence of quizalofop-P-ethyl, quizalofop-P-tefuryl and propaquizafop residues in plants, processed commodities, rotational crops and livestock, EFSA considered the conclusions derived in the framework of Directive 91/414/EEC as well as the European authorisations reported by Member States (including the supporting residues data). Based on the assessment of the available data, MRL proposals were derived and a consumer risk assessment was carried out. Although no apparent risk to consumers was identified, some information required by the regulatory framework was missing. Hence, the consumer risk assessment is considered indicative only and all MRL proposals derived by EFSA still require further consideration by risk managers. [ABSTRACT FROM AUTHOR]

Smooth barley [Hordeum glaucum (Steud.) Tzvelev] has recently evolved resistance to acetyl coenzyme-A carboxylase (ACCase) inhibitors in crop fields of South Australia. Experiments were conducted to determine the inheritance of quizalofop (quizalofop-p-ethyl) resistance in a population of smooth barley. Resistant plants (pollen donor) were crossed with susceptible plants (pollen acceptor) to generate an F1 generation, and the F1 hybrid was selfed to produce an F2 generation. It was observed that the resistant population was >60-fold more resistant to quizalofop as compared with the susceptible population and contained an amino acid change from isoleucine-to-leucine at 1781 in the carboxyl-transferase domain of the ACCase gene. The F1 individual was confirmed to be heterozygous by sequencing the carboxyl-transferase domain of ACCase, indicating that the inheritance of resistance is nuclear encoded. The F2 dose-response indicated that quizalofop resistance in smooth barley is conferred by a single partially dominant gene. The F2 plants segregated in a 3:1 ratio when treated with 6.2 g quizalofop ha-1, and sequencing of the ACCase gene also revealed that resistance alleles segregated in a 1:2:1 ratio, as expected for single-gene inheritance. This study confirms that quizalofop resistance in smooth barley from Australia is inherited by a single, partially dominant nuclear allele encoding a mutation in ACCase that confers resistance at the field rate. [ABSTRACT FROM AUTHOR]

Intercropping is an effective strategy to maximize production potential, profits, and land use efficiency. Sowing winter rapeseed in rice fields is a common cultivation technique in the Yangtze River basin in China, which is the world’s largest region for rapeseed production. However, the 10–15 days crop overlap in rapeseed-rice cultivation results in low and unstable yields. In this study, we investigated, using both pot and field experiments, whether presoaking oil rape seeds with Quizalofop- p -ethyl (QPE) improved winter hardiness and yield. For the field trials, rapeseed was cultivated during two growing seasons from 2009 to 2011, in no-tillage fallow rice fields at the experimental site of Wuhan. Without QPE application, seedling quality was low for rapeseed sown in pots, and grown in shady conditions, or in the fallow rice field. Seedlings showed excessive elongation of the crown, resulting in low yields and yield-related traits at maturity. Soaking seeds in QPE improved the growth and survival of rapeseed seedlings, and improved their length, weight, and root neck diameter traits. Furthermore, the treatment decreased crown length during winter. Overall yield and related traits were enhanced by the QPE treatment. The most effective concentration of QPE was 120 ppm. Storing seeds for 2–10 months after soaking in QPE reduced any inhibitory effect of the treatment on germination rate and plant height. Our analyses demonstrated that treating seeds with QPE (120 ppm) increased the yield of rapeseed in a rice-relay cropping system. [ABSTRACT FROM AUTHOR]

The degradation of the herbicides metazachlor (MTZ) and quizalofop-p-ethyl (QZE) was investigated in three different loamy (L) soils on thin-layer chromatography plates under natural solar light and dark conditions. Both herbicides degraded significantly faster under sunlight irradiation. The degradation rate of MTZ followed single first-order kinetics, and the determined half-life under sunlight and dark conditions were 18 and 78 days in L soil, 13 and 39 days in silty loam (SL) soil and 15 and 64 days in silty clay loam (SCL) soil, respectively. For QZE, first-order multi-compartment kinetic model fitted better for the description of the degradation rates. The half-life of the herbicide was determined at 0.6 and 2.9 days in L soil, 0.8 and 3.5 days in SL soil and 1.0 and 3.9 days in SCL soil, under sunlight and dark conditions, respectively. The putative degradation products (DPs) of herbicides have been determined by liquid chromatography time-of-flight mass spectrometry. MTZ oxalic acid was identified as the probable major DP of MTZ in the studied soils under sunlight conditions. For QZE three putative DPs were identified in all soils: quizalofop-p-acid and demethylated-quizalofop-p-acid under sunlight and dark conditions, while hydroxy-quizalofop-p-ethyl was detected only in samples under sunlight exposure. [ABSTRACT FROM PUBLISHER]

Quizalofop-p-ethyl (QPE) is a post-emergence herbicide that effectively controls grass weeds and is often detected in the environment. However, the biochemical and molecular mechanisms of QPE degradation in the environment remains unclear. In this study, a highly effective QPE-degrading bacterial strain J-2 was isolated from acclimated activated sludge and identified as a Pseudomonas sp., containing the QPE breakdown metabolite quizalofop acid (QA) identified by Liquid Chromatography-Ion Trap-Mass Spectrometry (LC-IT-MSn) analysis. A novel QPE hydrolase esterase-encoding gene qpeH was cloned from strain J-2 and functionally expressed in Escherichia coli BL21 (DE3). The specific activity of recombinant QpeH was 198.9 ± 2.7 U mg-1 for QPE with Km and Kcat values of 41.3 ± 3.6 μM and 127.3 ± 4.5 s-1. The optimal pH and temperature for the recombinant QpeH were 8.0 and 30 °C, respectively and the enzyme was activated by Ca2+, Cd2+, Li+, Fe3+ and Co2+ and inhibited by Ni2+, Fe2+, Ag+, DEPC, SDS, Tween 80, Triton X, β-mercaptoethanol, PMSF, and pCMB. In addition, the catalytic efficiency of QpeH toward different AOPP herbicides in descending order was as follows: fenoxaprop-P-ethyl > quizalofop-P-tefuryl > QPE > haloxyfop-P-methyl > cyhalofopbutyl > clodinafop-propargyl. On the basis of the phylogenetic analysis and multiple sequence alignment, the identified enzyme QpeH, was clustered with esterase family V, suggesting a new member of this family because of its low similarity of amino acid sequence with esterases reported previously. . [ABSTRACT FROM AUTHOR]

A natural consortium, named L1, of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9 was obtained from quizalofop- p -ethyl (QE) polluted soil. The consortium was able to use QE as a sole carbon source for growth and degraded 100 mg L −1 of QE in 60 h. Strain JT-3 initiated the catabolism of QE to quizalofop acid (QA), which was used by strain JT-9 as carbon source for growth and to simultaneously feed strain JT-3. A novel esterase EstS-JT, which was responsible for the transformation of QE to QA and essential for the mineralization of QE by the consortium, was cloned from strain JT-3. EstS-JT showed low amino acid identity to other reported esterases from esterase family VIII and represents a new member of this family. The deduced amino acid sequence contained the esterase family VIII conserved motifs S-X-X-K, YSV and WAG. The purified recombinant EstS-JT displayed maximal esterase activity at 35 °C and pH 7.5. An inhibitor assay, site-directed mutagenesis and 3D modeling analysis revealed that S 64 , K 67 and Y 175 were essential for catalysis and probably comprised the catalytic center of EstS-JT. Additionally, EstS-JT had broad substrate specificity and was capable of hydrolyzing p -nitrophenyl esters (C 2 -C 8 ) and various AOPP herbicides. [ABSTRACT FROM AUTHOR]

A convenient fluorescence quenching method for determination of Quizalofop-p-ethyl(Qpe) was proposed in this paper. Eosin Y(EY) is a red dye with strong green fluorescence (λex/λem = 519/540 nm). The interaction between EY, Pd(II) and Qpe was investigated by fluorescence spectroscopy, resonance Rayleigh scattering(RRS) and UV–Vis absorption. Based on changes in spectrum, Pd(II) associated with Qpe giving a positively charged chelate firstly, then reacted with EY through electrostatic and hydrophobic interaction formed ternary chelate could be demonstrated. Under optimum conditions, the fluorescence intensity of EY could be quenched by Qpe in the presence of Pd(II) and the RRS intensity had a remarkable enhancement, which was directly proportional to the Qpe concentration within a certain concentration range, respectively. Based on the fluorescence quenching of EY-Pd(II) system by Qpe, a novel, convenient and specific method for Qpe determination was developed. To our knowledge, this is the first fluorescence method for determination of Qpe was reported. The detection limit for Qpe was 20.3 ng/mL and the quantitative determination range was 0.04–1.0 μg/mL. The method was highly sensitive and had larger detection range compared to other methods. The influence of coexisting substances was investigated with good anti -interference ability. The new analytical method has been applied to determine of Qpe in real samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The herbicide Quizalofop- P -ethyl (QpE) exerts toxic effects in fish, but limited information is currently available on its effects on the endocrine system. In the current study, adult zebrafish ( Danio rerio ) were exposed to different concentrations (0, 2, 20, 200 μg/L) of QpE for 30 days. In males, QpE exposure significantly increased plasma estradiol (E2) and vitellogenin (VTG) levels, concomitant with up-regulation of hepatic esr1 and vtg gene expression. In females, plasma sex hormone levels and VTG concentrations were not altered significantly, but an increased expression of hepatic esr1 in addition to decreased expression of hepatic vtg, esr2a and esr2b was observed. Marked histological lesions were also observed in the gonads of both males and females. Moreover, QpE exposure significantly increased transcriptional profiles of some genes in the HPG axis and liver in males, while the majority of these genes were down-regulated in females. Docking studies showed QpE forming stable interactions with the ligand-binding domain (LBD) of zebrafish ESR1 and ESR2a, suggesting QpE may bind to estrogen receptors (ESRs). This study for the first time reveals QpE as an endocrine-disrupting chemical (EDC) disrupting the zebrafish endocrine system in a sex-specific manner, whereby it increases estrogen axis activity in males and slightly decreases estrogen axis activity in females, which may be accounted for by QpE regulating steroidogenesis and/or activating ESR(s). [ABSTRACT FROM AUTHOR]

A field experiment was conducted at ZARS, Jhabua (M.P.) during kharif 2014 to find out most suitable and efficient method of weed control in soybean. The experiment consisted of nine treatments laid out in randomized block design with three replications. All the weed management practices led to significant reduction in density and dry matter of weeds as compared to weedy check. Two hand weeding (20 & 40 DAS) recorded lowest weed density (4.9/m²), weed dry matter (22.35 g/m²) with highest weed control efficiency of 59.67% and found at par with the application of Chlorimuron Ethyl @ 9gm/ha + Quizalofop-p-ethyl @ 50 g/ha (density 5.48/m², dry matter 26.62 g/m² and WCE of 51.97%) and Imazethapyr @ 35 g/ha + Imazamox @ 35 g/ha (density 6.13/m², dry matter 26.00 g/m² and WCE of 53.08%). Maximum yield of 1782 kg/ha was recorded in two hand weeding (20 & 40 DAS) closely followed by Chlorimuron Ethyl @ 9gm/ha + Quizalofop-p-ethyl @ 50 g/ha (1723 kg/ha) and Imazethapyr @ 35 g / ha + Imazamox @ 35 g/ha (1697 kg/ha). Reduction in soybean yield in weedy check to be recorded is 38.78 per cent when compared to weed free and 36.68 per cent in comparison to Chlorimuron Ethyl @ 9gm/ha + Quizalofopp-ethyl @ 50 g/ha. However, highest Benefit to Cost ratio is recorded in Chlorimuron Ethyl +Quizalofop-p-ethyl (3.26) closely followed by Imazethapyr + Imazamox (3.22) and Weed free (3.21). [ABSTRACT FROM AUTHOR]

A field experiment was conducted to examine the degradation and impact of two post-emergence herbicides (imazethapyr and quizalofop- p-ethyl) on soil ecosystems at a half recommended rate (HRE), recommended rate (RE), and double recommended rate (DRE) during kharif peanut cultivation. Herbicides were innocuous to soil microbial activity at HRE, however, showed some significant influences at RE and DRE, and exerted temporary toxic effects on microbial biomass carbon and fluorescein diacetate hydrolyzing activity. Dehydrogenase activity also declined for a shorter period except imazethapyr application at DRE. Acid phosphatase activity was inhibited whereas alkaline phosphatase activity fluctuated between promotion and inhibition, but promotion was predominant suggesting a direct role of alkaline soil environment. Soil NH and NO nitrogen were increased by the herbicides at initial (after 7 days) and last phases (after 30 days), respectively. After an early period of inhibition, urease activity returned to the control level after 30 days. Dissipation of imazethapyr residues fitted best to bi-exponential order rate kinetics at DRE and RE, whereas it followed first-order rate kinetics at HRE. The residues of quizalofop- p-ethyl were found only up to 1 day after application suggesting its rapid conversion to active acid metabolites. Both the herbicides had transient harmful effects on most of the soil microbiological parameters. [ABSTRACT FROM AUTHOR]

Quizalofop-P-ethyl (QE) is a selective, systemic, post-emergence aryloxyphenoxy propanoate (AOPP) herbicide for the control of annual and perennial grassy weeds in a variety of crops. An efficient QE-degrading bacterial strain, QE-9, was isolated from a QE-manufacturing facility in China and identified as Ochrobactrum sp. A 4.0 kb DNA fragment from QE-9 containing a full length esterase encoding gene was cloned and analyzed. Multiple sequence alignment showed that the esterase gene estqe encoded a 382 amino acid protein that contained the conserved S-X-X-K esterase motif and clustered within esterase family VIII, owning to a lack of beta-lactamase activity. Full-length estqe was amplified by PCR and cloned into plasmid pET-29a for functional expression in Escherichia coli BL21 (DE3). The purified recombinant esterase EstQE converted QE to quizalofop acid (QA) at an optimum temperature and pH of 45 °C and 8.0, respectively. Enzyme activity was severely inhibited by Cu 2+ , whereas, Ca 2+ and Mg 2+ significantly increased enzyme activity to 142 and 122% of the control, respectively. The inhibitors PMSF, pCMB, and DEPC as well as detergent SDS strongly inhibited esterase activity. Furthermore, EstQE was capable of hydrolyzing a wide range of other AOPP herbicides, in the following order of catalytic efficiency, quizalofop-P-ethyl > fenoxaprop-P-ethyl > clodinafop-propargyl > cyhalofop-butyl > quizalofop-P-tefuryl > haloxyfop-P-methyl. These results suggest that EstQE is a potential candidate for remediation of AOPP herbicide-contaminated environments. [ABSTRACT FROM AUTHOR]

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS) Austria, received an application from the company Makhteshim Agan Industries Ltd to modify the existing maximum residue levels (MRL) for the active substance propaquizafop in cauliflowers and various root and oilseed crops. In addition, the EMS Italy received an application from the company ADAMA Quena N.V. to modify the existing MRLs in head cabbages and the group ‘lettuces and salad plants’. Considering that propaquizafop is an ester variant of quizalofop and since two different MRL datasets are proposed for propaquizafop and quizalofop (including quizalofop‐P) under Regulation (EC) No 396/2005, EFSA suggests the two following options: 1) to set specific MRL values for propaquizafop for the crops under consideration; 2) to delete the MRLs for propaquizafop from the EU legislation and to report all MRLs for all quizalofop ester variants in the EU legislation as ‘quizalofop’, considering that the current residue definition reported as ‘quizalofop incl. quizalofop‐P’ would have to be amended to ‘quizalofop and quizalofop esters, including propaquizafop expressed as quizalofop (sum of isomers)’. Sufficient data were submitted to propose specific MRLs for propaquizafop for the crops under consideration, except for the group ‘lettuces and salad plants’ since a sufficient number of trials on open leaf varieties of lettuce has not been provided to support an extrapolation. The deletion of the MRLs for propaquizafop as proposed under option 2 would only request to increase the MRL for mustard seeds from the limit of quantification (LOQ) of 0.05 to 0.06 mg/kg. Based on the risk assessment results, EFSA concludes that the proposed uses of propaquizafop will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk.

A gas chromatography–tandem mass spectrometry (GC–MS/MS) method was developed for the quantitative analyses of quizalofop ethyl and quizalofop tefuryl herbicides as well as their metabolites (i.e., quizalofop and its conjugates). This method fulfills the residue definition established by Japan. Following sample reflux in a methanolic potassium hydroxide solution, the residues were converted to 6-chloro-2-methoxyquinoxaline (CMQ) and extracted with hexane. Cleanup was carried out using primary secondary amine and silica gel cartridges prior to GC–MS/MS analysis. The developed method was validated for quizalofop ethyl, quizalofop tefuryl, and quizalofop in six foods at 0.01 mg/kg and at their maximum residue limits set by Japan. A satisfactory analytical performance was achieved (trueness = 80–93%, relative standard deviation = 1–7%, limit of detection = 0.00025 mg/kg for all analytes), and no significant matrix effects were observed for the examined matrices. There were no interfering peaks near the retention time of CMQ, indicating the high selectivity of this method. A satisfactory recovery was also achieved for propaquizafop in soybeans, indicating that the proposed method also complies with the residue definition established by the European Union. This method is suitable for the regulatory analysis of quizalofop ethyl and quizalofop tefuryl residues. [Display omitted] • A GC–MS/MS method for quizalofop ethyl and quizalofop tefuryl was developed. • For analysis, the residues were converted to 6-chloro-2-methoxyquinoxaline. • The developed method showed satisfactory analytical performance. • The method complies with the residue definition established by Japan. • The method may also be applicable for analysis according to US and EU regulations. [ABSTRACT FROM AUTHOR]

An enantioselective chromatographic method to analyze enantiomers of quizalofop-ethyl and its metabolite quizalofop-acid was established using a high-performance liquid chromatography (HPLC) on (R, R) Whelk-O 1 column. The enantioselective degradation kinetics of quizalofop-ethyl and quizalofop-acid in three soils were investigated. Moreover, the interaction with urease and catalase in the soils and the acute toxicity to Eisenia foetida of quizalofop-ethyl were also determined in order to assess their metabolism mechanism and environmental risk. From the results, quizalofop-ethyl was configurationally stable and was hydrolyzed rapidly to quizalofop-acid, which also degraded enantioselectively but slowly, and the inversion of the S-(−)-quizalofop-acid into the R-(+)-quizalofop-acid was observed in Xinxiang soil. In addition, quizalofop-ethyl and quizalofop-acid enantioselectively affected urease activity but not catalase. The acute toxicity assays to earthworm indicated that the racemic quizalofop-ethyl and quizalofop-acid were more toxic than quizalofop-p-ethyl and quizalofop-p-acid respectively, dramatically, the toxicity of the metabolite was much higher than the parent compound. These results revealed the enantioselective degradation of quizalofop-ethyl and quizalofop-acid, and the differences of toxicity among the enantiomers of the parent compound and the metabolite, which should be considered in future environmental risk evaluation. [ABSTRACT FROM AUTHOR]

Field experiments were conducted during summer (April to June), 2010 and 2011 to study the effect of post-emergence herbicides in irrigated blackgram (ADT 5). Treatments comprising of three levels (50, 75 and 100 g/ha) of the postemergence herbicides viz., Imazethapyr 10% SL and Quizalofop ethyl 5% EC were tested alone and in combination and compared with hand weeding twice on 15 and 30 DAS(farmers' practice). Herbicides were sprayed on 15 DAS when the weeds were 2-4 leaves stage using flat-fan nozzle as per treatment schedule. The results revealed that minimum total weed density (8.44) and weed dry weight ( 27.2 g/m2) and higher weed control efficiency (84.4%) were obtained under combined application of imazethapyr and quizalofop ethyl as tank mix at 100 g /ha. However, this was comparable with application of both the herbicides at 75g /ha. Application of imazethapyr + quizalofop ethyl each at 75 g/ha registered significantly taller plants, higher dry matter production, more number of pods per plant, seeds per pod and higher grain yield (826 kg/ha), net returns (Rs.26621/ha) and benefit cost ratio (2.76). Thus, application of post- emergence herbicides imazethapyr + quizalofop ethyl each at 75 g /ha as tank mix on 15 DAS could be recommended for controlling of emerged weeds in irrigated blackgram. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS) Austria, received an application from the company Makhteshim Agan Industries Ltd to modify the existing maximum residue levels (MRL) for the active substance propaquizafop in cauliflowers and various root and oilseed crops. In addition, the EMS Italy received an application from the company ADAMA Quena N.V. to modify the existing MRLs in head cabbages and the group 'lettuces and salad plants'. Considering that propaquizafop is an ester variant of quizalofop and since two different MRL datasets are proposed for propaquizafop and quizalofop (including quizalofop-P) under Regulation (EC) No 396/2005, EFSA suggests the two following options: 1) to set specific MRL values for propaquizafop for the crops under consideration; 2) to delete the MRLs for propaquizafop from the EU legislation and to report all MRLs for all quizalofop ester variants in the EU legislation as 'quizalofop', considering that the current residue definition reported as 'quizalofop incl. quizalofop-P' would have to be amended to 'quizalofop and quizalofop esters, including propaquizafop expressed as quizalofop (sum of isomers)'. Sufficient data were submitted to propose specific MRLs for propaquizafop for the crops under consideration, except for the group 'lettuces and salad plants' since a sufficient number of trials on open leaf varieties of lettuce has not been provided to support an extrapolation. The deletion of the MRLs for propaquizafop as proposed under option 2 would only request to increase the MRL for mustard seeds from the limit of quantification (LOQ) of 0.05 to 0.06 mg/kg. Based on the risk assessment results, EFSA concludes that the proposed uses of propaquizafop will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk. [ABSTRACT FROM AUTHOR]

An efficient, simple, and green procedure for the synthesis of quinoxaline derivatives catalyzed by Fe 3 O 4 @SiO 2 –imid–PMA n nanoparticles at room temperature is described. This environmentally benign method provides several advantages such as mild reaction conditions, good to excellent yields, short reaction times, simple work-up and catalyst stability, easy preparation, heterogeneous nature and easy separation of the catalyst. Also, nanocatalyst can be easily recovered by a magnetic field and reused for the next reactions for at least 6 times without distinct deterioration in catalytic activity. SEM, BET, DLS and leaching of catalyst after each reaction cycle were investigated. Furthermore, antifungal activity of various derivatives against three phytopathogenic fungi ( Alternaria alternata , Pyricularia oryzae , and Alternaria brassicae ) was investigated. [ABSTRACT FROM AUTHOR]

A field experiment aimed to evaluate the bio-efficacy of new low dose herbicides applied in soybean and their residual effect on succeeding wheat was conducted during 2007-08 and 2008-09 at New Delhi. Results revealed that in soybean, post-emergence application of imazethapyr (100 g/ha) was more effective against Trianthema portulacastrum, Commelina benghalensis, Digitaria sanguinalis and Dactyloctenium aegyptium but pendimethalin (1500 g/ha) against Dactyloctenium aegyptium, Digitaria sanguinalis and Trianthema portulacastrum. Chlorimuron-ethyl provided effective control of broad-leaved weeds but failed to control grasses and sedges. Application of imazethapyr (100 g/ha) increased the seed yield of soybean by 66.49% over weedy check. Herbicidal application significantly suppressed the microbial population at 30 DAS which recovered at the harvest of soybean. The residual effect of chlorimuron-ethyl (6-12 g/ha) and imazethapyr (50-100 g/ha) applied in soybean resulted in significant reduction in population of all major weeds except Avena ludoviciana in wheat grown in rotation. No injury to wheat plant was observed due to residues of chlorimuron-ethyl (6-12 g/ha) and imazethapyr (50-100 g/ha) and other herbicides applied in soybean.

Key message: New herbicide resistance traits in wheat were produced through the use of induced mutagenesis. Abstract: While herbicide-resistant crops have become common in many agricultural systems, wheat has seen few introductions of herbicide resistance traits. A population of Hatcher winter wheat treated with ethyl methanesulfonate was screened with quizalofop to identify herbicide-resistant plants. Initial testing identified plants that survived multiple quizalofop applications. A series of experiments were designed to characterize this trait. In greenhouse studies the mutants exhibited high levels of quizalofop resistance compared to non-mutant wheat. Sequencing ACC1 revealed a novel missense mutation causing an alanine to valine change at position 2004 ( Alopecurus myosuroides reference sequence). Plants carrying single mutations in wheat's three genomes (A, B, D) were identified. Acetyl co-enzyme A carboxylase in resistant plants was 4- to 10-fold more tolerant to quizalofop. Populations of segregating backcross progenies were developed by crossing each of the three individual mutants with wild-type wheat. Experiments conducted with these populations confirmed largely normal segregation, with each mutant allele conferring an additive level of resistance. Further tests showed that the A genome mutation conferred the greatest resistance and the B genome mutation conferred the least resistance to quizalofop. The non-transgenic herbicide resistance trait identified will enhance weed control strategies in wheat. [ABSTRACT FROM AUTHOR]