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Background: The Groundnut or Goober peas (Arachis hypogaea L.) hold a prominent position as one of India’s most crucial food and cash crops. One of the serious bottlenecks that limit the productivity of groundnut is the weed menace. Methods: A field experiment was conducted at Perunthalaivar Kamaraj Krishi Vigyan Kendra, Puducherry during 2021 to 2023 to investigate the effects of integrated weed management practices on groundnut cultivation. The experimental setup followed a randomized block design with nine treatments, each replicated three times. The treatments comprised a range of weed management practices, including the pre-emergence herbicide pendimethalin and post-emergence herbicides like imazethapyr and quizalofop-ethyl. These herbicides were administered either individually or in conjunction with hand weeding once. In addition, hand weedings twice at 20 and 40 DAS were tested with unweeded check. Result: The experiment results of the two years study revealed that the application of Pendimethalin 30% EC + Imazethapyr 2% EC with quizalofop - p- ethyl at 15-20 DAS has gave the maximum plant height (74.7 cm), dry matter production (57.9 g /plant), higher pod yield (3922 kg/ha), haulm yield (5919 kg/ha), highest net return (Rs. 91763 ha -1) and B: C ratio (2.75). The strong positive correlations are plant height (0.96 and 0.97), shelling % (0.98 and 0.99), no. of pods plant-1 (0.98 and 0.99), dry matter production (0.98 and 0.99) and weed control efficiency (0.85 and 0.88). These variables had a positive impact on groundnut yield. [ABSTRACT FROM AUTHOR]

Field dodder (Cuscuta campestris yuncker) is an important parasitic weed that has negative impacts on the growth and yield of alfalfa (Medicago sativa L.). Effective control of field dodder in alfalfa crops is necessary to reduce yield losses. Field studies were conducted to evaluate the efficacy of various herbicides on field dodder in a new-seeded alfalfa crop at three locations (Karaj, Jiroft, and Urmia) in Iran during 2020–2021. The herbicides evaluated were imazethapyr (100 g a.i. ha−1), glyphosate (six doses ranging from 143 to 348 g a.i. ha−1 + ammonium sulfate at 8 kg ha−1), and propyzamide (1250, 1500, and 1750 g a.i. ha−1). The results demonstrated that propyzamide at 1750 g a.i. ha−1 provided complete control of field dodder in terms of percentage change in biomass at first (100%) and second (99%) cuttings of alfalfa in Urmia. The imazethapyr at 100 g a.i. ha−1 provided 96 and 87% control at the first and second cuttings, respectively, whereas propyzamide at 1750 g a.i. ha−1 showed the best efficacy in increasing alfalfa biomass at the first (up to 82%) and the second cuttings (up to 81%), depending on the location. Glyphosate provided reasonable control of the field dodder at the first (73%) and the second cutting (82%). However, at higher rates (307 and 348 g a.i. ha−1), it caused significant reductions in alfalfa biomass due to crop injury, especially at the first cutting. The use of propyzamide at 1750 g a.i. ha−1 is recommended for highly effective control of field dodder in alfalfa crops without compromising the crop yield. [ABSTRACT FROM AUTHOR]

AbstractThis study aimed to assess the efficacy of commonly used post-emergence herbicides under flooded rice fields, for Conyza spp. control. The greenhouse experiment employed a factorial setup with factor A denoting the presence or absence of a water layer post-application, and factor B representing different herbicides, to C. sumatrensis. In field trials, were applied when the rice plantation was on V3 stage. Evaluations were control (%), roots and shoot dry weight of Conyza spp., as well as injury (%), number of grains per panicle, and grain yield (ha−1) of rice. The applications of imazapyr + imazapic, florpyrauxifen-benzyl, imazethapyr, penoxsulam, quinclorac, bentazon, triclopyr-butyl, saflufenacil and ethoxysulfuron followed by water layer entry led to Conyza spp. control surpassing 80% at 28 DAA. The herbicides florpyrauxifen-benzyl, quinclorac, triclopyr-butyl, and saflufenacil, without flooding after application, demonstrated Sumatran fleabane control equal to or greater than 80% at 28 DAA. Effective water layer management is crucial for Conyza spp. control in zero-grade rice cultivation areas. [ABSTRACT FROM AUTHOR]

The management of invasive weeds on both arable and non-arable land is a vast challenge. Converting these invasive weeds into biochar and using them to control the fate of herbicides in soil could be an effective strategy within the concept of turning waste into a wealth product. In this study, the fate of imazethapyr (IMZ), a commonly used herbicide in various crops, was investigated by introducing such weeds as biochar, i.e., Parthenium hysterophorus (PB) and Lantana camara (LB) in sandy loam soil. In terms of kinetics, the pseudo-second order (PSO) model provided the best fit for both biochar-mixed soils. More IMZ was sorbed onto LB-mixed soil compared to PB-mixed soil. When compared to the control (no biochar), both PB and LB biochars (at concentrations of 0.2% and 0.5%) increased IMZ adsorption, although the extent of this effect varied depending on the dosage and type of biochar. The Freundlich adsorption isotherm provided a satisfactory explanation for IMZ adsorption in soil/soil mixed with biochar, with the adsorption process exhibiting high nonlinearity. The values of Gibb's free energy change (ΔG) were negative for both adsorption and desorption in soil/soil mixed with biochar, indicating that sorption was exothermic and spontaneous. Both types of biochar significantly affect IMZ dissipation, with higher degradation observed in LB-amended soil compared to PB-amended soil. Hence, the findings suggest that the preparation of biochar from invasive weeds and its utilization for managing the fate of herbicides can effectively reduce the residual toxicity of IMZ in treated agroecosystems in tropical and subtropical regions. [ABSTRACT FROM AUTHOR]

Weedy rice is the most challenging weed species to remove in rice production. We found a novel phenotype of seedling leaves which rapidly generates necrotic spots in response to imidazolinone herbicides in weedy rice, but its influencing factors and formation basis are still unknown. In this study, we used the leaf necrotic spot-producing type of weedy rice as the material. First, leaf necrotic spots were defined as physiological and vacuole-mediated cell necrosis by microscopic examination. The imazethapyr concentration was positively correlated with the degree of necrotic spots occurring, while the action site was in accordance with necrosis using herbicide stability tests combined with fluorescence parameters. Furthermore, transcriptome analysis revealed significant differences in the gene expression of endoplasmic reticulum stress and the lipid metabolism membrane structure damage pathway during necrosis, as confirmed by transmission electron microscopy. The light–temperature test also showed that high temperature and intense light could promote the appearance of necrotic spots. These experimental results are helpful in clarifying the process and basis of imazethapyr in inducing the rapid generation of necrotic spots in rice leaves and providing new insight into understanding the mechanism of response to imidazolinone herbicides and the control of weedy rice. [ABSTRACT FROM AUTHOR]

Imazethapyr is a widely used imidazolinone herbicide worldwide, and its potential adverse effects on non-target plants have raised concerns. Understanding the mechanisms of imazethapyr phytotoxicity is crucial for its agro-ecological risk assessment. Here, the comprehensive molecular responses and metabolic alterations of Arabidopsis in response to imazethapyr were investigated. Our results showed that root exposure to imazethapyr inhibited shoot growth, reduced chlorophyll contents, induced photoinhibition and decreased photosynthetic activity. By non-target metabolomic analysis, we identified 75 metabolites that were significantly changed after imazethapyr exposure, and they are mainly enriched in carbohydrate, lipid and amino acid metabolism. Transcriptomic analysis confirmed that imazethapyr significantly downregulated the genes involved in photosynthetic electron transport and the carbon cycle. In detail, 48 genes in the photosynthetic lightreaction and 11 genes in Calvin cycle were downregulated. Additionally, the downregulation of genes related to electron transport in mitochondria provides strong evidence for imazethapyr inhibiting photosynthetic carbon fixation and cellular energy metabolism as one of mechanisms of toxicity. These results revealed the molecular and metabolic basis of imazethapyr toxicity on non-target plants, contributing to environmental risk assessment and mitigate negative impact of imazethapyr residues in agricultural soils. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during kharif 2021 to assess the effect of various weed management practices in groundnut at Agronomy Instructional Farm, Chimanbhai Patel College of Agriculture, Sardarkrushinagar, Dantiwada Agricultural University, Sardarkrushinagar on loamy sand soil. Among different treatments, two hand weeding at 20 and 40 days after sowing (DAS) recorded significantly higher pod and haulm yield (1980 and 3082 kg/ha, respectively) and found at par with interculturing and hand weeding at 15 and 30 DAS (1892 and 2950 kg/ha, respectively), post-emergence application of sodium acifluorfen 16.5 + clodinafop-propargyl 8 EC @ 165+80 g/ha (1835 and 2864 kg/ha, respectively) and imazethapyr 35 WG + imazamox 35 WG @ 70 g/ha (1800 and 2811 kg/ha, respectively) as compared to unweeded check (846 and 1333 kg/ha, respectively) due to effective suppression of grasses, sedges, broad leaf and total weeds at 60 DAS and at harvest with higher weed control efficiency and lower weed index values. [ABSTRACT FROM AUTHOR]

Cluster bean (Cyamopsis tetragonoloba L.) is grown under both rainfed and irrigated conditions in Haryana and weeds pose serious threat to its production under both the conditions. Owing to increasing labour cost, there is need for chemical weed management, but, there is no chemical recommendation for weed management in cluster bean in Haryana. So, a field experiment was conducted during kharif season of 2018 and 2019 at Research Farm, Department of Agronomy, CCS Haryana Agricultural University, Hisar, India in a semi-arid climate. The experiment was laid out in split-plot design having three replications, with three irrigation levels viz., no post-sown irrigation, one irrigation and two irrigations in main plots, while five weed management practices viz., pendimethalin 1.0 kg/ha as PRE, imazethapyr 70 g/ha as PRE, imazethapyr 70 g/ha at 21 DAS, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS and farmers' practice (2 hand weedings at 3 and 5 WAS) in sub-plots. The cluster bean crop was infested with Cyperus rotundus, Convolvulus arvensis, Digera arvensis and Echinochloa colona. The dry weight of weeds at 60 DAS and at harvest increased with the increasing irrigation levels. Among the weed management practices, two hand weedings at 3 and 5 WAS, produced minimum weed dry weight at 30 DAS, 60 DAS and harvest, while, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS was found most effective in controlling the weeds among the chemical methods. During both the years, maximum seed yield of cluster bean was produced by irrigating the crop with two irrigations (1036 and 726 kg/ha), which was statistically at par with one irrigation (1009 and 682 kg/ha, during 2018 and 2019, respectively). Two hand weedings at 3 and 5 WAS, was found superior to chemical weed control treatments in producing seed yield (1121 and 754 kg/ha during 2018 and 2019, respectively). However, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS produced highest seed yield (968 and 674 kg/ha, during 2018 and 2019, respectively), which was statistically similar to imazethapyr 70 g/ha PRE (932 and 654 kg/ha, during 2018 and 2019, respectively) and both of them were superior to imazethapyr 70 g/ha at 21 DAS and pendimethalin 1.0 kg/ha as PRE. The bacterial and PSB count at harvest of cluster bean crop increased with increase in irrigation levels and bacterial population was lower with soil application of herbicides (either pendimethalin or imazethapyr) as compared to foliar application of herbicides and 2 HW treatments, however, PSB population was not affected by weed management practices. Maximum herbicide residue at harvest of the cluster bean crop was found in imazethapyr 70 g/ha at 21 DAS and followed by imazethapyr 70 g/ha PRE and imazethapyr + imazamox (RM) 70 g/ha at 20 DAS. Reduction in the germination, growth and yield of mustard was observed due to residual effect of the chemicals applied in cluster bean during both years of study, maximum being with imazethapyr 70 g/ha at 21 DAS followed by imazethapyr 70 g/ha PRE and imazethapyr + imazamox (RM) 70 g/ha at 21 DAS. [ABSTRACT FROM AUTHOR]

In order to investigate the lethal dose of herbicide and its effect on physiological and biochemical characteristics of foxtail millet, in this study, three-leaf stage Jigu25 seedlings were treated with different concentrations of imazethapyr in seedling tray culture. The lethal dose of imazethapyr on Jigu25 seedlings was screened under different treatment concentrations and time. At the same time, the changes of chlorophyll content, electrolyte permeability, malondialdehyde(MDA) content, peroxidase(POD), superoxide dismutase(SOD) and catalase(CAT) activities of foxtail millet seedlings after imazethapyr treatment were measured. The results showed that the lethal dose of imazethapyr on Jigu25 seedlings was 3 375 mL/ha, and it was found that with the increase of herbicide concentration(2 250, 3 375, and 4 500 mL/ha) and the extension of treatment time, the corresponding physiological indexes of chlorophyll content, electrolyte permeability, MDA content, POD, SOD and CAT activities of Jigu25 seedlings showed significant changes at different time compared with the control. This study showed that after spraying a lethal dose of 3 375 mL/ha of imazethapyr, foxtail millet seedlings were subjected to stress and physiological protection mechanism was activated. [ABSTRACT FROM AUTHOR]

The imidazolinone group of herbicides generally work for controlling weeds by limiting the synthesis of the aceto-hydroxy-acid enzyme, which is linked to the biosynthesis of branched-chain amino acids in plant cells. The herbicide imazethapyr is from the class and the active ingredient of this herbicide is the same as other herbicides Contour, Hammer, Overtop, Passport, Pivot, Pursuit, Pursuit Plus, and Resolve. It is commonly used for controlling weeds in soybeans, alfalfa hay, corn, rice, peanuts, etc. Generally, the herbicide imazethapyr is safe and non-toxic for target crops and environmentally friendly when it is used at low concentration levels. Even though crops are extremely susceptible to herbicide treatment at the seedling stage, there have been no observations of its higher dose on lentils (Lens culinaris Medik.) at that stage. The current study reports the consequence of imazethapyr treatment on phenolic acid and flavonoid contents along with the antioxidant activity of the phenolic extract. Imazethapyr treatment significantly increased the activities of several antioxidant enzymes, including phenylalanine ammonia lyase (PAL), phenol oxidase (POD), glutathione reductase (GR), and glutathione-s-transferase (GST), in lentil seedlings at doses of 0 RFD, 0.5 RFD, 1 RFD, 1.25 RFD, 1.5 RFD, and 2 RFD. Application of imazethapyr resulted in the 3.2 to 26.31 and 4.57–27.85% increase in mean phenolic acid and flavonoid content, respectively, over control. However, the consequent fold increase in mean antioxidant activity under 2, 2- diphenylpicrylhdrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay system was in the range of 1.17–1.85 and 1.47–2.03%. Mean PAL and POD activities increased by 1.63 to 3.66 and 1.71 to 3.35-fold, respectively, in agreement with the rise in phenolic compounds, indicating that these enzyme’s activities were modulated in response to herbicide treatment. Following herbicide treatments, the mean thiol content also increased significantly in corroboration with the enhancement in GR activity in a dose-dependent approach. A similar increase in GST activity was also observed with increasing herbicide dose. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal 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.)

Compacted soils may be negatively affecting the selectivity of herbicides applied in preemergence in the soybean crop. Therefore, the present work aimed to investigate possible negative effects on the morphophysiological characters of soybean plants, as well as on the agronomic and yield performances of this crop. For this purpose, two trials were carried out, one in a greenhouse and the other under field conditions. In a greenhouse, the study was carried out in a completely randomized design in a 2 × 8 factorial, with five replications, while in the field, the design used was randomized blocks, with the treatments arranged in split-plot (2 × 8), with six repetitions. The first factor/plot corresponded to the physical condition of the soil: compacted or not compacted, while the second factor/subplot was constituted by the application of preemergence herbicides: clomazone, diclosulam, flumioxazin, S-metolachlor, [imazethapyr + flumioxazin], [pyroxasulfone + flumioxazin], and [sulfentrazone + diuron], plus a control without herbicide. In the greenhouse study, there was a significant interaction between soil compaction and herbicides applied in preemergence for the relative index of chlorophyll b and root dry mass. Furthermore, the isolated herbicide factor did not promote significant changes in any of the morphophysiological variables evaluated. Compaction alone had a negative impact on the variables relative index of chlorophyll a and carbon assimilation rate, with reductions in the values of these variables when the soybean was submitted to growth in compacted soil. For the field experiment, there were no significant interactions between the factors for any of the analyzed variables, nor the effect of herbicides alone. The isolated soil compaction factor negatively impacted the plant stand and the thousand-grain mass of soybean, showing reductions in the values of this parameter when the soybean was grown in compacted soil. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of reduced imazethapyr rates integrated with non‐chemical weed management treatments on weed control and pinto bean (Phaseolus vulgaris L.) seed yield, the field studies were carried out at the Research Field of University of Tabriz, Iran in 2016 and 2017. The experiment was a factorial randomised complete block design with five levels of imazethapyr rates and four levels of non‐chemical managements. The weed density and biomass were reduced in all non‐chemical weed management treatments when combined with imazethapyr, compared with those treated with imazethapyr only (control). In both years, non‐chemical weed management treatments increased pinto bean seeds per plant and seed yield when integrated with imazethapyr. Pinto bean seeds per plant and seed yield in 2017 were greater than those in 2016 and also there was no significant difference between those in 0.75X and 1X. The relative ranking of non‐chemical weed management treatments for weed control efficacy and pinto bean seed yield was hand weeding > straw mulch > living mulch. Integration of imazethapyr with non‐chemical weed managements could increase the weed control efficacy and seed yield of pinto bean whereas would reduce herbicide application in sustainable production systems. [ABSTRACT FROM AUTHOR]

Background: A landscape‐scale probability‐based sampling of Iowa soybean [Glycine max (L.) Merr.] fields was conducted in 2013 and 2019; Amaranthus tuberculatus [Moq.] J.D. Sauer seed was collected from 97 random geospatial selected fields. The objectives were to evaluate the prevalence and distribution of herbicide‐resistant A. tuberculatus (waterhemp) in soybean fields and evaluate temporal changes over 6 years. Amaranthus tuberculatus seedlings were evaluated for resistance to imazethapyr, atrazine, glyphosate, lactofen and mesotrione at 1× and 4× label rates. Results: Resistance to imazethapyr, glyphosate, lactofen and mesotrione at the 1× rate increased significantly from 2013 to 2019 and was found in 99%, 97%, 16% and 15% of Iowa A. tuberculatus populations in 2019, respectively. Resistance to atrazine at the 4× rate increased over time; atrazine resistance was found in 68% of populations in 2019. Three‐way multiple herbicide‐resistant A. tuberculatus was the most frequent and increased significantly to 4× rates from 16% in 2013 to 43% of populations in 2019. All A. tuberculatus populations resistant to HPPD‐inhibitor herbicides also were resistant to atrazine. Conclusion: To the best of our knowledge, this is the first probability‐based study that presented evolution of A. tuberculatus herbicide resistance over time. The results demonstrated that imazethapyr, atrazine and glyphosate resistance in Iowa A. tuberculatus populations was frequent whereas resistance to lactofen and mesotrione was less frequent. Most Iowa A. tuberculatus populations evolved resistance to multiple sites of action over time. The results of our study are widely applicable given the similarities in weed management practices throughout the Midwest United States. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction Weeds are one of the most problematic factors in chickpea production systems and chemical control of weeds is limited in Iran because of registered selective herbicides for this crop are not available for farmers. In this situation, optimizing of herbicide application (especially soil-applied herbicides) is one way that can help farmers to combat with weeds. Incorporated By Sowing (IBS) is one of the best way for optimizing of non-selective soil herbicides application in crops. The purpose of this experiment is to investigate the possibility application of non-selective soil-applied herbicides in directed planting of chickpea via IBS. Material and Methods Application possibility of non-selective herbicides in directed sowing of chickpea was evaluated in Ardabil and Zanjan in 2020. The treatments were arranged in a strip plot experiment with randomized complete block design and 3 replications. The vertical factor was herbicide application (including: trifluralin, metribuzin, pendimethalin, imazethapyr, and their combination with (phenmedipham+desmedipham+ethofumesate), and also oxyfluorfen and weedy and weed free controls. Horizontal factor was incorporated by sowing (IBS) methods (including: incorporate by seed planter and cultivator+seed planter). Seed germination of chickpea, weed density and biomass and chickpea grain yield were evaluated 30 days after herbicide application and in the end of chickpea growth. Results and Discussion IBS methods did not have a significant impact on weed and chickpea density and biomass. Therefore, the use of a cultivator before seed planting is only recommended when the seedbed is inadequately prepared or if pre-planting weed control has not been effectively executed. In contrast, herbicides had significant effects on weeds population and chickpea in experimental locations. In Ardabil, pendimetalin and pendimetalin + (phenmedipham + desmedipham + ethofumesate) were the only treatments that had low efficacy on weeds (with 48.9 and 51.7 % weed biomass reduction respectively) and other treatments had no significant difference in 30 days after herbicides application. In the end of growing season, the highest weeds biomass reduction (in compared with control) were recorded in trifluralin, metribuzin and imazethapyr in combination with (phenmedipham + desmedipham + ethofumesate) and oxyfluorfen (with 84, 83, 80 and 70 of control (%) respectively). In Zanjan, single application of trifluralin and metribuzin and their combination with (phenmedipham + desmedipham + ethofumesate) and combination of imazethapyr with (phenmedipham + desmedipham + ethofumesate) had the highest weed control with 79, 71, 78.6 and 75.5 % respectively. In contrast with Ardabil, the lowest weed control efficacy was recorded in oxyfluorfen plots (22.4%). Grain yield of chickpea was also high in trifluralin + (phenmedipham + desmedipham + ethofumesate) and was low in imazethapyr in Zanjan and Ardabil. Conclusions Application of soil herbicides (including: Metribuzin and Trifluralin) in chickpea is possible only if, farmers use them just before sowing and incorporate the herbicides into the seedbed during the sowing process. [ABSTRACT FROM AUTHOR]

The understanding of adsorption desorption of herbicides in soil is important to predict their environmental fate. The effect of properties of soils, temperature and ionic state of imazethapyr on its sorption was assessed using batch equilibration method. Freundlich adsorption coefficient ranged from 0.596 to 10.495 μg1−ng−1mLn and was significantly influenced by organic matter, pH, clay content and mineralogy of soils. As solution pH was increased from 1.5 to 8.0, adsorption increased in acidic soil while it decreased in alkaline soils. The variability in adsorption with pH of solution was due to existence of imazethapyr predominately in cationic form at low solution pH and in anionic form at high solution pH. ΔH° ranged from – 29.11 to – 16.19 kJ mol−1 suggesting adsorption was a spontaneous exothermic process. Desorption was slow and more hysteretic in alkaline soils indicating irreversible binding of imazethapyr to these soils which can cause a phytotoxic effect on succeeding crops. Principal component analysis suggested that imazethapyr has moderate mobility in studied soils and can contaminate surface and groundwater. The amendment of soils with farmyard manure was an effective management practice to reduce leaching of imazethapyr. [ABSTRACT FROM AUTHOR]

In the mid‐southern United States, rice (Oryza sativa L.) is flooded primarily to suppress weed germination and growth. Two experiments were conducted to determine whether herbicide performance in conventional or Clearfield rice weed control programs was affected by intermittent flooding. The effects of flooding and herbicide program on barnyardgrass [Echinochloa crus‐galli (L.) P. Beauv] control, rice grain yield, and water applied were investigated at the Delta Research and Extension Center in Stoneville, MS, on Sharkey clay (very fine, smectitic, thermic Chromic Epiaquert). For herbicides commonly applied in conventional (clomazone, quinclorac, pendimethalin, thiobencarb, fenoxaprop‐ethyl, cyhalofop‐butyl, and bisypriboac sodium) or Clearfield rice weed control programs (imazethapyr plus bispyribac‐sodium followed by imazethapyr, imazamox or bispyribac‐sodium), intermittent flooding had no adverse effect on barnyardgrass control relative to a continuous flood. Moreover, initiating irrigation when the perched water table drops to 8 inches below the soil surface had no effect on rice grain yield and reduced water applied by 51%. Mid‐southern US rice producers can capture the water‐saving benefits of intermittent flooding while having no adverse effects on herbicide activity or crop productivity in conventional and Clearfield systems. Core Ideas: Barnyardgrass control did not differ between intermittently and continuously flooded systems.Initiating irrigation when perched water table drops 8 inches below soil surface had no effect on rice grain yield.Intermittent flooding reduced water applied 51% compared to continuous flooding. [ABSTRACT FROM AUTHOR]

Effectively controlling target organisms while reducing the adverse effects of pesticides on non-target organisms is a crucial scientific inquiry and challenge in pesticide ecotoxicology research. Here, we studied the alleviation of herbicide (R)-imazethapyr [(R)-IM] to non-target plant wheat by active regulation between auxin and secondary metabolite 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazine-3(4H)-one (DIMBOA). We found (R)-IM reduced 32.4% auxin content in wheat leaves and induced 40.7% DIMBOA accumulation compared to the control group, which effortlessly disrupted the balance between wheat growth and defense. Transcriptomic results indicated that restoration of the auxin level in plants promoted the up-regulation of growth-related genes and the accumulation of DIMBOA up-regulated the expression of defense-related genes. Auxin and DIMBOA alleviated herbicide stress primarily through effects in the two directions of wheat growth and defense, respectively. Additionally, as a common precursor of auxin and DIMBOA, indole adopted a combined growth and defense strategy in response to (R)-IM toxicity, i.e., restoring growth development and enhancing the defense system. Future regulation of auxin and DIMBOA levels in plants may be possible through appropriate methods, thus regulating the plant growth-defense balance under herbicide stress. Our insight into the interference mechanism of herbicides to the plant growth-defense system will facilitate the design of improved strategies for herbicide detoxification. [ABSTRACT FROM AUTHOR]

Amaranthus tuberculatus (waterhemp) is a pervasive weed of the Mid‐west and ‐south United States and is not native to North Carolina but infestations in crop fields have been reported recently. Amaranthus tuberculatus has evolved resistance to seven herbicide groups and multiple herbicide‐resistant populations are common where the species is native. The reported A. tuberculatus infestations in North Carolina have not been controlled with herbicides but no formal herbicide resistance characterisation has been conducted to date. Glasshouse dose–response experiments were conducted to determine the susceptibility of a population collected from Surry County, North Carolina to commonly applied postemergence herbicides compared to a herbicide‐susceptible population collected from Story County, Iowa. The Surry County population survived labelled rates of imazethapyr, atrazine, glyphosate, fomesafen, and mesotrione; the Story County population was controlled with these herbicides. Further, 2,4‐D, dicamba, and glufosinate effectively controlled the Surry and Story County populations. Molecular sequencing assays were subsequently conducted to determine if altered target sites facilitated resistance in the acetolactate synthase (ALS), 5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS), photosystem II (psbA), and protoporphyrinogen oxidase (PPX2) genes. The Surry County population carried a Trp574Leu and ∆Gly210 mutations in the ALS and PPX2 gene, respectively. No mutations that would confer resistance were found in the EPSPS or psbA gene for either population. The results of both experiments provide evidence that a five‐way herbicide‐resistant A. tuberculatus population has encroached North Carolina. More research is needed to determine the mechanisms of resistance to atrazine, glyphosate, and mesotrione. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga 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 Revista Caatinga is the property of Revista Caatinga 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 imidazolinone group of herbicides generally work for controlling weeds by limiting the synthesis of the aceto-hydroxy-acid enzyme, which is linked to the biosynthesis of branched-chain amino acids in plant cells. The herbicide imazethapyr is from the class and the active ingredient of this herbicide is the same as other herbicides Contour, Hammer, Overtop, Passport, Pivot, Pursuit, Pursuit Plus, and Resolve. It is commonly used for controlling weeds in soybeans, alfalfa hay, corn, rice, peanuts, etc. Generally, the herbicide imazethapyr is safe and non-toxic for target crops and environmentally friendly when it is used at low concentration levels. Even though crops are extremely susceptible to herbicide treatment at the seedling stage, there have been no observations of its higher dose on lentils (Lens culinaris Medik.) at that stage. The current study reports the consequence of imazethapyr treatment on phenolic acid and flavonoid contents along with the antioxidant activity of the phenolic extract. Imazethapyr treatment significantly increased the activities of several antioxidant enzymes, including phenylalanine ammonia lyase (PAL), phenol oxidase (POD), glutathione reductase (GR), and glutathione-s-transferase (GST), in lentil seedlings at doses of 0 RFD, 0.5 RFD, 1 RFD, 1.25 RFD, 1.5 RFD, and 2 RFD. Application of imazethapyr resulted in the 3.2 to 26.31 and 4.57–27.85% increase in mean phenolic acid and flavonoid content, respectively, over control. However, the consequent fold increase in mean antioxidant activity under 2, 2- diphenylpicrylhdrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay system was in the range of 1.17–1.85 and 1.47–2.03%. Mean PAL and POD activities increased by 1.63 to 3.66 and 1.71 to 3.35-fold, respectively, in agreement with the rise in phenolic compounds, indicating that these enzyme’s activities were modulated in response to herbicide treatment. Following herbicide treatments, the mean thiol content also increased significantly in corroboration with the enhancement in GR activity in a dose-dependent approach. A similar increase in GST activity was also observed with increasing herbicide dose.

Among the factors that limit the productive potential of soybean crops, stands out lodging, in addition to competition with weeds. Given this, the importance of soybean pre-emergence herbicides for different purposes is highlighted; however, they have to be evaluated for selectivity. This study aimed to evaluate the growth and agronomic performance of soybean applied with pre-emergence herbicides. Experiment 1 was conducted in the 2017-2018 season at two locations, and experiment 2 in the 2016-2017 season at one location. Treatments consisted of the application of pre-emergence herbicides in soybean in a randomized block design with four replications. Crop injury and chlorophyll indices (experiment 1) and variables related to agronomic performance (experiments 1 and 2) were assessed. Diclosulam and chlorimuron showed potential for application at pre-emergence to reduce plant height and consequently plant lodging. Moreover, diclosulam, chlorimuron, sulfentrazone, flumioxazin, s-metolachlor, pendimethalin, trifluralin, imazethapyr/flumioxazin, and oxyfluorfen did not negatively affect agronomic performance when applied at pre-emergence of soybean. This study evidenced the selectivity of pre-emergence herbicides to soybean. [ABSTRACT FROM AUTHOR]

Background: Among various biotic factors limiting pigeon pea yield, weeds are of prime importance which can causes seed yield losses up to 80 per cent. Therefore current study aims to evaluate the impact of imidazolinones on weeds in pigeon pea (Cajanus cajan L.). Methods: The experiment was laid out in randomized block design using eighteen treatments replicated thrice. To control the weeds in pigeon pea, imidazolinones alone and its combination with pendimethalin were applied and rest other cultural practices for cultivation of pigeon pea were adopted according to the package and practices of CCA HAU, Hisar. Result: Among all weed controls treatments, two hoeing at 40 and 70 DAS found most effective to control all kind of weeds. PRE application of imidazolinones was comparatively more effective than POE application. Among different weed species, Cynodon dactylon was not controlled by any of the herbicide treatment and PRE application of pendimethalin @ 1000 g/ha did not control Digera arvensis and Cyperus rotundus. Whereas, PRE application of pendimethalin + imazethapyr @ 1000 + 75 g/ha provided best control of total weeds leads to lowest nutrient uptake by weeds. Therefore, PRE application of pendimethalin + imazethapyr @ 1000 + 75 g/ha proved to be an effective and a profitable alternative to the existing recommendation (two hoeing at 25 and 45 DAS) of weed control in pigeon pea in Haryana locality. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental 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.)

A bioassay study was conducted to determine the differences in the susceptibility of selected crops to simulated imazethapyr residues based on morphological and anatomical parameters. Sugar beet, white mustard, and rapeseed oil were found to be the most sensitive based on ED50 values for the root length and the root fresh weight. Corn and sunflower were less sensitive, and wheat was the least sensitive. The measured anatomical parameters confirmed the different sensitivities of the tested plants, as evidenced by a shortening of the meristem and elongation zones, a reduction in the distance between the root tip and the absorption zone, and the distance between the root tip and the point where the primordium of the lateral root appears. An imazethapyr residue level equivalent to ED20 (for root length) did not cause serious morphological changes in the less sensitive plants, nor did it cause significant changes in the length of the root cap, the beginning of the root absorption zone (root hair region), the beginning of lateral root formation (i.e., the permanent region), and the number of root primordia per root length. Therefore, ED20 could be proposed as an acceptable residue level (ARL) or herbicide residue level at which these plants can be safely sown. [ABSTRACT FROM AUTHOR]

The evolution of herbicide-resistant weeds is the major challenge for chemical management worldwide, increasing production costs, and reducing yield. This work aimed to evaluate the putative resistance of the Amaranthus hybridus population from Candido Mota (CMT) to glyphosate and imazethapyr and to investigate the non-target site mechanisms involved. Dose–response studies were conducted under greenhouse conditions and the control and biomass reduction were evaluated 28 days after application (DAA). Absorption, translocation, and metabolization studies were evaluated at 72 h after treatment (HAT) using radiometric techniques. The dose–response results show different responses among populations to glyphosate and imazethapyr. The CMT population was not controlled with labeled herbicide doses. Based on biomass reduction, the resistance factor was 16.4 and 9.4 to glyphosate and imazethapyr, respectively. The CMT absorbed 66% of 14C-glyphosate and 23% of 14C-imazethapyr at 72 HAT. Although the CMT population absorbed more glyphosate than the susceptible population (12.6%), translocation was impaired for both herbicides in the CMT when compared to the SUS population. There was no evidence that herbicide metabolization was involved in CMT resistance to the herbicides studied. Understanding the mechanisms endowing resistance allows better decision-making. This is the first study that describes non-target-site resistance mechanisms in an Amaranthus hybridus population from Brazil. [ABSTRACT FROM AUTHOR]

The article focuses on investigating the impact of herbicides (ethalfluralin, imazethapyr, and metribuzin) on the symbiosis between soybean and rhizobium, particularly under different soil pH conditions. It study aims to understand how the electrical charge properties of herbicides may contribute to variations in their toxicity on soybean-rhizobium symbiosis, emphasizing the importance of considering soil pH in such evaluations.

Introduction Rain-fed Lentil (Lens culinaris Medik.) is vulnerable to weed competition because of its tiny stature, slow establishment, and limited vegetative growth. Weed control is necessary for maximum seed yield and seed quality. Crop yield losses are primarily a result of competition with weeds for nutrients, moisture and space. Therefore, weed control at this period plays an important role to gain high roduction. Although the vast majority of lentil production is under rain-fed conditions, there is a little published information on weed control with herbicides in rain-fed lentils. Herbicides due to efficiency and expense savings play a essential role in weed control. The purpose of this research was to determine the best time to application effective herbicides in weeds control for the maximum rain-fed Lentil production in Khorramabad. Materials and Methods The Lentil (Lens culinaris Medik.) field experiment was carried out as split plot based on complete randomized block design with three replications during 2017-2018 in Khorramabad (48.21°E, 33.29°N, 1170 m above sea level, 450 mm average yearly precipitation) Iran. The following herbicides were used: Oxyfluorfen (EC 24%) 1 Li ha-1, Isoxaflutole (SC 480) 200 Ml ha-1, Flumetsulam(WG 800) 20 g ha-1, Metribuzin (WP 70%) 500g ha-1, Pendimethalin Aria(EC33%) 4 li ha-1, Pendimethalin Prowl (CS45.5%) 4li ha-1, Imazethapyr (SL10%) 350 ml ha-1 and Pendimethalin prowl 2li ha-1plus Imazethapyr 350 ml ha-1. Herbicide applicatioin time at 3 levels; IAP application (Immediately after planting), PRE application and IBCE (eraly post herbicide application at fourth lentil node stage) was assigned to the main and sub plots respectively. The fields were in wheat cultivation in the year before the experiments. The soil at the test sites was a silty loam with a pH of 7.9 and organic matter of 1.11%. Lentil was sown at a density of 75 kg seed ha-1 by hand on December 21, 2017. Herbicides were sprayed with an electric knapsack sprayer MATABI (calibrated to deliver 300 L ha-1. In order to evaluate the effect of treatments on weeds density and biomass, at the beginning of lentil flowering, sampling was done from a surface of 0.3 m-2 area and weed density and weed biomass recorded. At lentil physiological maturity, the yield and yield components were measured by harvesting lentil plants from a 1-m2 area in each plot (Izadi & Maghsoudi, 1400). The data were subjected to the analysis of variance using SAS. Means were compared using Duncan's Multiple Range test at P=0.05 level of significance. Results and Discussion The results indicated that the lowest weed density and weed biomass were associated with Flumetsulam and Prowl plus Imazethapyr. The average weed densities for the postemergence and preemergence treatments of the eight evaluated herbicides were 14.9% and 31.0% lower, respectively, compared to the herbicide application immediately after planting. The least herbicide injury effects on the Lentil crop were assigned to the Pendimethalin Aria, Pendimethalin Prowl, Prowl plus Imazethapyr, Imazethapyr and Flumetsulam. In the case of Oxyfluorfen herbicide, weed density for early postemergence application treatment was 84.1% lower than in PRE application. In the case of Isoxaflutole herbicide, the mean weed density for application immediately after planting was 79.3% lower than for early post-application. In the case of Flumetsulam herbicide, the mean of weed biomass for application immediately after planting was 73.3% and 66.6% less than preemergence and early post-application, respectively. With the exception of Flumetsulam herbicide, there was no significant difference between the different herbicide application times in terms of weed biomass. The highest average Lentil grain yield per unit area was observed when Flumetsulam herbicide was applied immediately after planting. On the other hand, the lowest average Lentil grain yield per unit area was recorded when Isoxaflutole herbicide was applied immediately after planting. No significant differences in Lentil grain yield per unit area were found between the different application times for the herbicides Metribuzin and Imazethapyr. Based on cluster analysis grouping of relative efficacy of control treatments, immediately after planting application or preemergence application of Flumetsulam and early postemergence application of Imazethapyr were better than the other herbicide treatments for Lentil weed control, whereas the lowest relative efficacy was related to preemergence application of Oxyfluorfen, immediately after planting application of Isoxaflutole and Metribuzin, and preemergence application of Pendimethalin Arya. Conclusion Based on the results of this research, the application of flumezolam immediately after planting (20 g ha-1) and imazatapir(350 ml ha-1) as pre-emergence application have had more efficiency for weed control in lentil than other herbicide treatments, while the pre-emergent application of oxyfluorfen, the application immediately after planting of isoxaflotel and metribyozin have had the effects of plant burning on lentil crops and the pendimethalin Aria herbicide is not recommended in lentil farms because of to the lack of control of broadleaf weeds under normal conditions in lentil fields. In general, among the experimental treatments, in terms of the level of control efficiency and the level of safety for the lentil crop, the application of flumetsulam immediately after planting was the best herbicide treatment. [ABSTRACT FROM AUTHOR]

Chicory (Cichorium intybus) is a commercially cultivated root crop in many countries of the world. Weeds have a depressing effect on the growth and development of root chicory. There are currently no herbicides registered for use on chicory in the Russian Federation. The objective of this work was to identify potential herbicides for controlling a broad range of weed species under the soil and climatic conditions of the Russian Federation. For the field experiment, herbicides were selected according to: (1) previous studies in USA, EU and South Africa; (2) the spectrum of weeds controlled; and (3) the probability of crop damage. All the herbicides used were registered in Russia for the control of certain weeds in other crops. Crop biomass, damage, and weed control were assessed to identify suitable herbicides. The results suggested that the best weed control herbicides would be a Zeta, SC (100 g/L imazethapyr) and Paradox, SC (120 g/L imazamox). These herbicides controlled, on average, 80% or more of the dicotyledonous weeds such as lamb's quarters (Chenopodium album), field pennycress (Thlaspi arvense), and sow thistles (Sonchus spp.). Since these herbicides do not reduce chicory biomass, they can be considered for registration or use on chicory. [ABSTRACT FROM AUTHOR]

Nowadays, large areas of agricultural land are contaminated with chemical plant-protection products. Agricultural soils are also susceptible to oil pollution as a result of accidents on oil pipelines. Bioremediation of such soils from oil with the help of hydrocarbon-oxidizing bacteria is hindered by the presence of additional pollutants such as herbicides. In this work, seven strains of Pseudomonas were isolated and identified, which showed differences in ability of oil biodegradation (32.7–77.3%). All strains showed resistance to herbicides based on 2,4-D and substances from the class of imidazolinones, possessed phosphate-solubilizing and nitrogen-fixing activity, and produced indolyl-3-acetic acid (305–1627 ng/mL culture liquid). They stimulated the growth of barley and clover in soil with oil, as well as the growth of clover in soil with herbicide. In a vegetative experiment (duration 30 days, initial oil content in soil 2% wt., herbicide based on imazethapyr 0.002% wt.) of barley plants and P. alcaligenes UOM 10 or P. frederiksbergensis UOM 11, oil degradation was 48.1–52.7%, the same strains and clover plants, 37.9–38.6%. The studied bacteria have the potential to be used in the bioremediation of oil-contaminated agricultural soils, including in combination with phytomeliorant plants. [ABSTRACT FROM AUTHOR]

In order to efficiency of different herbicides on weed control, forage yield, crop growth rate (CGR) of alfalfa (Medicago sativa L), an experiment with nine treatments based on randomized complete block design (RCBD) with three replications at the research field of Iranian Research Institute of Plant Protection located in Meshkindasht, Karaj, during 2014-2016 was conducted. The treatments consisted of Eradicane 4.1 g ai/ha (EPTC), Metribuzin 525 g ai/ha, 2,4-DB 1269 g ai/ha, 2,4-DB 1480 g ai/ha, Bentazon 144 g ai/ha, Imazethapyr 50 g ai/ha (with 200 ml Sitogit), Imazethapyr 100 g ai/ha (with 200 ml Sitogit), non-herbicide control (weedy) and whole-season weeding control (weed free). Among different herbicides, application of Imazethapyr (1L/ha) led to control of Flixweed (Descurania Sophia) and wild mustard (Sinapis arvensis) (control percentage more than 95%). The lowest percentage of dry weight reduction in both weeds (flixweed and wild mustard) was related to Eradicane herbicide, which was 42 and 41% in the first cutting and 40 and 35% in second cutting. The highest and lowest fresh and dry weight of alfalfa (qualitative forage yield in 5 cutting were observed weed free and application of Metribuzin herbicide treatments. Also, index of crop growth rate (CGR) was more in weed free and application of Imazethapyr herbicide (1L/ha) treatments. Therefore, weed control in alfalfa established, application of Imazethapyr herbicide (1L/ha) as post emergence (3-4 leaves of weeds) is recommended. [ABSTRACT FROM AUTHOR]

Background: Groundnut encounters severe infestation of weed especially during the early stages of growth due to less crop canopy which allows higher weeds growth and thus crop becomes more susceptible to weed competition. During rainy season, effective and economical weed control is not possible through manual and mechanical weeding due to unfavorable soil conditions and also the unavailability of costly labours. Herbicides have been accepted as cost effective tool to manage weed menace in groundnut. The current study aims to study the efficancy of different post-emergence and pre-mix combination of post-emergence herbicides on weeds, growth and yield of groundnut. Methods: The field experiment was conducted at AICRP Weed Management Field, Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (M.S.) during three consecutive Kharif seasons of 2015-2017. The experiment was laid out in randomized block design with ten treatments replicated thrice. The treatments comprised of one pre emergence and five different post emergence herbicides and compared with weed free and weedy check. Result: The results revealed that weed free was found most effective to control weeds in groundnut with lowest weed count, weed dry matter of weeds and maximum gross monetary returns (Rs. 117641/ha), net monetary returns (Rs. 80894/ha). Among the herbicides, application of Imazethapyr + Imazomox 0.10 kg/ha POE 20 DAS produced less weed count and weed dry matter and highest weed control efficiency (80.68%) and lower weed index (6.71%) as well as maximum growth, yield attributes and pod yield in groundnut over all the other herbicidal treatments viz. plant height (30.25), dry matter accumulation (18.11 g), number of pods/plant (32.35) and pod yield (2448 kg/ha) and highest pooled B:C ratio (3.74). [ABSTRACT FROM AUTHOR]

[Objectives] The paper was to systematically study the technology of weed control in alfalfa field. [Methods] Reviving alfalfa field and newly sown alfalfa field after emergence were selected, and the effects of different herbicides on weed control and alfalfa yield were discussed. [Results] The optimal herbicides after alfalfa reviving were 5% imazethapyr and 10% imazethapyr, and the optimal dosages were 1.5 and 1.05 L/hm2, respectively. The optimal herbicides after emergence of newly born alfalfa were 5% imazethapyr and 10% imazethapyr, and the optimal dosages were 1.5 and 0.75 L/hm2, respectively. [Conclusions] This study will provide a technical support for high quality production of alfalfa. [ABSTRACT FROM AUTHOR]

Imazethapyr, a post-emergent herbicide used in worldwide soybean and corn crops, induces genetic and biochemical alterations in aquatic vertebrates. This study examined the relationship between biomarkers at different organization levels and imazethapyr real-life route exposure in Boana pulchella adults. Frogs were exposed to imazethapyr-based formulation Pivot® H (10.59%) at concentrations representing possible acute routes: field runoff (S1:10 mg.L−1), exposure after direct foliar application (S2:100 mg.L−1) and during direct foliar application (S3:1000 mg.L−1). Post-exposure, endpoints levels were evaluated: organism alterations, biochemical activities and cytogenetic assays. Forty-eight hours post-exposure, antioxidant enzymes decrease, micronuclei induction and DNA damage were observed in all scenarios, while cholinesterase activity increase and body condition reduction were observed in frog-exposed to S3. Ninety-six hours post-exposure, frogs showed glutathione-S-transferase inhibition in S1, micronuclei induction in S2 and S3, and DNA-damage increase in S3. Herbicides routes of exposures in real-life could indicate that authorized applications have a risk to amphibian populations. [ABSTRACT FROM AUTHOR]