Herbicides Pendimethalin Research Articles

Soil dissipation and efficacy on itchgrass of soil-applied residual herbicides pendimethalin and clomazone in Louisiana sugarcane.

Sugarcane (Saccharum sp.) growers in Louisiana report that the widely used soil residual herbicide, pendimethalin, is less effective at controlling itchgrass (Rottboellia chochinchinensis), possibly through accelerated dissipation from repeated applications. Some growers have started to use another herbicide, clomazone, in place of pendimethalin for itchgrass control when pendimethalin does not provide the necessary control. Little is known about the dissipation of these two herbicides, especially when applied together, in diverse sugarcane soils in Louisiana. Thus, the objective of the research was to measure the dissipation of pendimethalin and clomazone in soils having high itchgrass pressure. Soil samples from five fields were fortified (4 μg g-1) with clomazone and pendimethalin and monitored over the course of 163 days under laboratory conditions. Herbicide levels were determined by extracting the herbicides from soil with acetonitrile and analyzing the extracts with high performance liquid chromatography (HPLC). The results indicate that clomazone is persistent in the soils studied, with a degradation half-life (DT50) of ≥79 days. Pendimethalin dissipates more rapidly in soil with a DT50 ranging from 7 to 59 days. All itchgrass plants showed injury to herbicide but many grew out of symptoms, and responses were not consistent between soil types. Pendimethalin dissipation varied greatly between soil types, yet clomazone was generally persistent in each soil tested. However, when these soils were seeded with itchgrass, pendimethalin was more effective at controlling itchgrass than clomazone. Although persistent in the soils tested, the leaching potential of clomazone may limit its long-term effectiveness. Published 2024. This article is a U.S. Government work and is in the public domain in the USA.

Unveiling responses and mechanisms of spice crop chive exposure to three typical pesticides using metabolomics combined with transcriptomics, physiology and biochemistry

Pesticides are frequently used to control target pests in the production of spice crops such as chives (Allium ascalonicum). However, little information is available on the responses and underlying mechanisms of pesticide exposure in this crop. Our findings revealed that the uptake, transportation, and subcellular distribution of three typical pesticides—the fungicide pyraclostrobin (PAL), insecticide acetamiprid (ATP), and herbicide pendimethalin (PND) in chives, as well as their physiological, biochemical, metabolic, and transcriptomic responses—were dependent on pesticide properties, especially hydrophobicity. The distribution of PAL and PND in chives decreased in the order root > stem > leaf, but the distribution order of ATP was the opposite. The proportion of PAL and PND in the solid phase of the root cells gradually increased, but ATP mainly existed in the cell-soluble component, indicating that the latter had an upward translocation ability and thus mainly accumulated in the leaves. Malondialdehyde levels in chive leaves were not significantly affected by exposure to these pesticides; however, the activities of superoxide dismutase (SOD) and catalase (CAT) in chive leaves increased significantly. Moreover, these pesticides exhibited critical differences in chive responses through the interaction of metabolites and regulation of differentially expressed genes. PAL dramatically influenced five carbohydrate metabolic pathways (34.35 %), disturbing the starch-to-sucrose balance. ATP strongly affected five amino acid (AC) metabolic pathways (33.38 %), enhancing four free amino acid levels. PND notably affected eight fatty acid (FA) metabolic pathways (25.38 %), increasing two unsaturated and decreasing one saturated FA. Simultaneously, PND, ATP, and PND accumulated in the chives could be detoxified through metabolic pathways mediated by cytochrome P450 (P450) and glycosyltransferase (GT)/glutathione S-transferase (GST), producing phase I (7, 4, and 5) and II (11, 13, and 10) metabolites, respectively. This study provides important molecular insights into the responses and underlying mechanisms of spice crop exposure to pesticides.

Compatibility Analysis of Metolachlor and Pendimethalin for Weed Control in Arabica Coffee Plants

Losses caused by the presence of weeds in an agricultural business are often associated with the ability of weeds as strong competitors for plants to obtain water, nutrients, sunlight, and growing space. A mixture of metolachlor and pendimethalin herbicides is expected to control important weeds of various classes in coffee plants. The purpose of the research was to determine the effect of two herbicide mixtures at different doses on weeds in coffee plantations. This research used a 4 X 4 factorial randomized block design with 2 repetitions, resulting in 32 experimental plots. The first factor was metolachlor herbicide and the second was pendimethalin herbicide, each factor consisting of 4 levels with 0.00, 0.75, 1.75 and 2.25 kg ha-1 doses. The observed parameters consisted of (1) dominance count value, (2) percentage of controlled weeds, (3) weed coverage, (4) weed population, and (5) weed dry weight. The results showed that there was a very significant effect on the combined interaction of metolachlor and pendimethalin herbicide mixtures on the percentage of controlled weeds, percentage of weed closure at 21 and 28 DAA, and weed dry weight at 28 and 42 DAA with the best dose combination at b.a. 1.50 kg ha-1 which could increase the efficiency of weed control. Meanwhile, the percentage of controlled weeds, percentage of weed cover at 14 DAA, and weed population at 28 and 42 DAA showed very significant results independently with a dose of b.a. 2.25 kg ha-1

Quantitative Variables Analysis, Growth and Yield of Groundnut (Arachis hypogaea L.) under Different Weed Management Practices

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.

Environmental presence and toxicological outcomes of the herbicide pendimethalin in teleost fish.

Herbicides are often detected in aquatic ecosystems due to residential and agricultural applications and can harm aquatic organisms once deposited into water systems. Pendimethalin is part of the dinitroaniline chemical family and is applied to crops like corn, legumes, potatoes, and soybeans. The potential toxicity of pendimethalin to aquatic species is understudied compared to other widely studied herbicides, like atrazine and glyphosate. The objectives of this review were to (1) collate information on sub-lethal responses to pendimethalin exposure in fish, (2) evaluate how exposure studies relate to environmental concentrations, and (3) identify putative bioindicators for exposure studies. Overall, studies reporting pendimethalin in water systems worldwide indicate a range of 100-300 ng/L, but levels have been reported as high as ~15 µg/g in sediment. In teleost fish, studies demonstrate developmental toxicity, immunotoxicity, and behavioral disruptions. The strongest evidence for pendimethalin-induced toxicity involves oxidative stress, although studies often test toxicity at higher concentrations than environmentally relevant levels. Using the Comparative Toxicogenomics Database, pathway analysis reveals linkages to neurotoxicity and mechanisms of neurodegeneration like "Ubiquitin Dependent Protein Degradation", "Microtubule Cytoskeleton", "Protein Oxidation and Aggregation in Aging", and "Parkinson's Disease". Other prominent pathways included those related to mTOR signaling and reproduction. Thus, two potential mechanisms underlying pendimethalin-induced toxicity in fish include the neural and reproductive systems. This review synthesizes current data regarding environmental fate and ecotoxicology of pendimethalin in teleost fish and points to some putative physiological and molecular responses that may be beneficial for assessing toxicity of the herbicide in future investigations.

Comparative acute toxicity of pesticides to tadpoles of a tropical anuran (<em>Epipedobates anthonyi</em>), a North American native anuran (<em>Lithobates sphenocephalus</em>) and a standard fish species

Global amphibian declines have the highest incidence in tropical regions, but most of the ecotoxicological data on amphibians is collected on temperate northern hemisphere anuran species. We tested the hypothesis that tropical anuran larvae (Epipedobates anthonyi) would be more sensitive to pesticides than a North American native species (Lithobates sphenocephalus). For 12 pesticides, 96-hr range-finding acute toxicity tests were conducted to determine if mortality occurred at environmentally relevant levels. Based on those studies, two substances were selected for additional time-to-event analyses in both species as well as median lethal concentration (LC50) calculations. Time-to-event results indicated that the two species appear to be roughly equivalent in their sensitivity to the two tested pesticides. Significant differences between species were not consistent across concentrations for either the insecticide terbufos or the herbicide pendimethalin. The utility of LC50 data was mixed with one LC50 providing an arbitrarily large standard error around the LC50 precluding informative comparisons across species. However, standard LC50 methods allowed data collection that continues to contribute to our understanding of the protectiveness of fish as surrogates for anuran larvae. While our data set is limited, it appears that testing temperate species would be protective for tropical species in ecological risk assessments. Our data also support the continued use of fish as surrogates for amphibian larvae as none of the species were more sensitive to the tested pesticides than rainbow trout (Oncorhynchus mykiss), the standard sensitive fish species used for acute toxicity testing.

Effect of Some Chemical Herbicides on the Weeds Accompanying the Field's Peanut Crop

A field experiment was conducted during the spring season of 2021 in a selected field of preparative Ibn Al-Bitar occupational/ Al-Hussainiya region in Holy Karbala. The experiment involved cultivating peanut plants (Arachis hypogaea L.), specifically a local variety, in soil characterized by a clay loam texture. The experiment aimed to determine the most effective chemical herbicides for controlling weed growth in conjunction with the Peanut crop. The experiment utilized a randomized complete block design (RCBD) with three replications. The study encompassed six conditions: weedy and weed-free, which were under manual control for the entire duration of the growing season. Furthermore, there were treatments that involved the administration of chemical herbicides before planting, specifically Trifluralin and Pendimethalin, which were applied ten days before the planting phase. Additionally, post-planting herbicides, namely Oxyfluorfen and Clethodim, were sprayed during the vegetative growth phase of the plant as well as at the initiation of the flowering stage. The herbicides were administered according to the prescribed dosages. The findings demonstrated significant differences in the management procedure utilizing chemical herbicides throughout a 30-day period of applying said herbicides. This discrepancy became apparent when evaluating the two herbicides, specifically Oxyfluorfen and Pendimethalin, which produced the lowest quantity of broad-leaf weeds, with a recorded density of 4.6 and 7.6 plants m-2, respectively. Additionally, the results demonstrated that notable disparities were observed after 60 days from the application of herbicides. Specifically, the herbicides Pendimethalin and Oxyfluorfen exhibited the lowest density of broad-leaf weeds, with a count of 4.6 and 6.0 m-2 plants, respectively. Moreover, the impact of herbicides on narrow-leaf weed was examined at 30 and 60 days post-spraying. There was no significant difference in the means of the herbicides, and the herbicides Oxyfluorfen and Pendimethalin yielded the least density of broad leaf weeds after 90 days of herbicide application, with quantities of 6.0 and 6.3 plant m-2, respectively. Similarly, concerning narrow-leaf weed density on the same date, the herbicides Trifluralin, Clethodim,, and Ox-yfluorfen exhibited superiority in achieving the lowest density of narrow-leaf weeds, with quantities of 5.0, 5.3, and 5.6 plant m-2, respectively. Furthermore, no statistically significant difference was observed among these herbicides. The findings demonstrate the superiority of the herbicides Oxyfluorfen and Pendimethalin in achieving the highest percentage of control for broad-leaf weeds after 30, 60, and 90 days of herbicide application. Regarding the specific dates for the narrow-leaf weeds, the herbicides Oxyfluorfen, Clethodim, and Trifluralin exhibited superiority in providing optimal control. In contrast to alternative treatments involving herbicides, the herbicide Oxyfluorfen showcased the most diminished mean mass and the utmost level of hindrance on both extensive and limited-leafed weeds. Keywords: Herbicides; Oxyfluorfen; Pendimethalin; Clethodim; Trifluralin; Weeds; Narrow leaf; Broad leaf.

A field study on the combined use of pre-emergence herbicide and Clearfield® technology for ryegrass management in wheat crops

Weed interference in wheat crops are known to cause productivity losses. The objective of this work was to evaluate pre-emergence herbicide application efficiency combined with Clearfield® technology (CL) in ryegrass (Lolium multiflorum) management in wheat crops. A field experiment was conducted from July 2020 to December 2021 using randomized block design in a 2×5 factorial arrangement with four replications. Treatments consisted of combinations of pre-emergence herbicide application - without and with pendimethalin at 1365 g a.i. ha-1 (in 2020 crop season) or without and with pyroxasulfone at 125 g a.i. ha-1 (in 2021 crop season) and post-emergence herbicide application - without application; imazamox at 49, 70, and 91 g a.i. ha-1, or pyroxsulam at 18 g a.i. ha-1. Wheat cultivars used were TBIO Capricho CL® and TBIO Ello CL®. The following characteristics were evaluated: phytotoxicity, ryegrass control, plant height, number of spikes m-2, mean spike weight, 100-grain weight, and grain yield. Treatments phytotoxicity did not exceed 5%, being visible only at 7 DAA, from 14 DAA no injury was observed. The combined application of pre-emergence herbicides pendimethalin or pyroxasulfone with post-emergence herbicides imazamox or pyroxsulam provided superior control of ryegrass than the isolated applications. This management resulted in ryegrass control ranging from 88.8% to 100% in 2020 and from 82.3% to 100% in 2021. In general, grain yield was also higher in treatments with combined pre- and post-emergence applications. The pre-emergence herbicide application in combination with CL technology was effective in managing ryegrass, preventing weed interference, and ensuring the productive potential of wheat crops

Managing Weed-Crop Interactions Enhances Chickpea (Cicer arietinum L.) Chemical Components.

Chickpea (Cicer arietinum L.) is a major pulse crop worldwide, renowned for its nutritional richness and adaptability. Weeds are the main biotic factor deteriorating chickpea yield and nutritional quality, especially Asphodelus tenuifolius Cav. The present study concerns a two-year (2018-19 and 2019-20) field trial aiming at evaluating the effect of weed management on chickpea grain quality. Several weed management practices have been here implemented under a factorial randomized complete block design, including the application of four herbicides [bromoxynil (C7H3Br2NO) + MCPA (Methyl-chlorophenoxyacetic acid) (C9H9ClO3), fluroxypyr + MCPA, fenoxaprop-p-ethyl (C18H16ClNO5), pendimethalin (C13H19N3O4)], the extracts from two allelopathic weeds (Sorghum halepense and Cyperus rotundus), two mulches (wheat straw and eucalyptus leaves), a combination of A. tenuifolius extract and pendimethalin, and an untreated check (control). Chickpea grain quality was measured in terms of nitrogen, crude protein, crude fat, ash, and oil content. The herbicides pendimethalin (Stomp 330 EC (emulsifiable concentrate) in pre-emergence at a rate of 2.5 L ha-1) and fenoxaprop-p-ethyl (Puma Super 7.5 EW (emulsion in water) in post-emergence at a rate of 1.0 L ha-1), thanks to A. tenuifolius control, showed outstanding performance, providing the highest dietary quality of chickpea grain. The herbicides Stomp 330 EC, Buctril Super 40 EC, Starane-M 50 EC, and Puma Super 7.5 EW provided the highest levels of nitrogen. Outstanding increases in crude protein content were observed with all management strategies, particularly with Stomp 330 EC and Puma Super 7.5 EW (+18% on average). Ash content was highly elevated by Stomp 330 EC and Puma Super 7.5 EW, along with wheat straw mulching, reaching levels of 2.96% and 2.94%. Crude fat content experienced consistent elevations across all treatments, with the highest improvements achieved by Stomp 330 EC, Puma Super 7.5 EW, and wheat straw mulching applications. While 2018-19 displayed no significant oil content variations, 2019-20 revealed the highest oil content (5.97% and 5.96%) with herbicides Stomp 330 EC and Puma Super 7.5 EW, respectively, followed by eucalyptus leaves mulching (5.82%). The results here obtained are of key importance in the agricultural and food sector for the sustainable enhancement of chickpea grain's nutritional quality without impacting the environment.

Herbicide association for simultaneous control of seeds and emerged plants of Rottboellia exaltata L.

The species Rottboellia exaltata L. (itchgrass) has become an important weed in cultivated areas, requiring management studies to enhance its control. This study aimed to evaluate the effectiveness of the herbicides pendimethalin (1200 g ha−1), clomazone (1000 g ha−1), indaziflam (100 g ha−1), and trifluralin (900 g ha−1) applied in pre-emergence in association with diquat (400 g ha−1) and glyphosate (1175 g ha−1), in addition to their isolated application, in the simultaneous control of emerged plants and seeds of R. exaltata. The experiments were conducted in a greenhouse in a completely randomized design, with four replications. Evaluations were performed at 7, 14, 21, 28, 35, and 42 days after application (DAA). The associations of diquat + pendimethalin, diquat + clomazone, diquat + indaziflam, diquat + trifluralin, glyphosate + pendimethalin, glyphosate + clomazone, glyphosate + indaziflam, and glyphosate + trifluralin controlled 100% of the species and prevented the germination of new fluxes of R. exaltata. Regarding isolated applications, only clomazone did not differ from herbicide associations in controlling the species. Thus, the interaction promoted by the association between desiccant and residual herbicides was the best option to control R. exaltata, consisting of an important management tool to control the species, considering the post-emergence control and the seed bank.

Growth and Yield Attributes of Groundnut (Arachis hypogaea L.) as Influenced by Tank-mix Application of Early Post Emergence Herbicides

Background: Groundnut or peanut (Arachis hypogaea L.) is known as the ‘king’ of oilseeds. It is one of the most important food and cash crop of India. Among different constraints that limit the productivity of groundnut, weed menace is one of the serious bottlenecks. A field experiment was conducted at Perunthalaivar Kamaraj Krishi Vigyan Kendra, Puducherry during 2019 to 2020 to study the tank mix application of post-emergence herbicides for efficient weed control in Groundnut. Methods: The experiment was laid out in randomized block design with 13 treatments and replicated thrice. The treatments consisted of weed management practices viz., pre emergence herbicide pendimethalin and post emergence herbicide viz., imazethapyr, quizalofop-ethyl and those herbicides used either alone or combined with hand weeding once. In addition, hand weedings twice at 15 and 30 DAS were tested with unweeded check. Result: The experiment results of the two years study revealed that the Pendimethalin @ 1.5 kg ai ha-1 (PE) + tank mix of Imazethpyr (40%) + Quizalofop ethyl (60%) at 20-30 DAS recorded maximum plant height (58.17 cm), DMP (36.81 g plant-1), Significantly higher pod yield (3752 kg ha-1), highest net income (₹ 90,762 ha-1) and B:C ratio (2.80). Correlation and Regression analysis also indicated that the yield attributes had a positive impact on groundnut yield.

Calf thymus ds-DNA intercalation with pendimethalin herbicide at the surface of ZIF-8/Co/rGO/C3N4/ds-DNA/SPCE; A bio-sensing approach for pendimethalin quantification confirmed by molecular docking study

Pendimethalin (PND) is a herbicide that is regarded to be possibly carcinogenic to humans and toxic to the environment. Herein, we fabricated a highly sensitive DNA biosensor based on ZIF-8/Co/rGO/C3N4 nanohybrid modification of a screen-printed carbon electrode (SPCE) to monitor PND in real samples. The layer-by-layer fabrication pathway was conducted to construct ZIF-8/Co/rGO/C3N4/ds-DNA/SPCE biosensor. The physicochemical characterization techniques confirmed the successful synthesis of ZIF-8/Co/rGO/C3N4 hybrid nanocomposite, as well as the appropriate modification of the SPCE surface. The utilization of ZIF-8/Co/rGO/C3N4 nanohybrid as a modifier was analyzed using. The electrochemical impedance spectroscopy results showed that the modified SPCE exhibited significantly lowered charge transfer resistance due to the enhancement of its electrical conductivity and facilitation of the transfer of charged particles. The proposed biosensor successfully quantified PND in a wide concentration range of 0.01–35 μM, with a limit of detection (LOD) value of 8.0 nM. The PND monitoring capability of the fabricated biosensor in real samples including rice, wheat, tap, and river water samples was verified with a recovery range of 98.2–105.6%. Moreover, to predict the interaction sites of PND herbicide with DNA, the molecular docking study was performed between the PND molecule and two sequence DNA fragments and confirmed the experimental findings. This research sets the stage for developing highly sensitive DNA biosensors that will be used to monitor and quantify toxic herbicides in real samples by fusing the advantages of nanohybrid structures with crucial knowledge from a molecular docking investigation.

Evaluation of Some Herbicides for Weed Control in Wheat (Triticum aestivum L.) in Northern Sudan

A field trial was conducted at Hudeiba Research Station Farm,River Nile State, Sudan, during 2001/2002, 2002/2003 and 2003/2004winter seasons. The objective was to evaluate the activity and selectivityof three pre-emergence herbicides for weed control in wheat. Theherbicides treatments were pendimethalin (Stomp) at 1.2, 1.8 and 2.4 kga.i. ha-1, oxyfluorfen (Goal) at 0.24, 0.36 and 0.48 kg a.i ha -1 andoxadiazon (Ronstar) at 0.72, 1.08 and 1.44 kg a.i ha -1 . The prevailingweed species in the experimental sites were Ipomoea sp, wild mustard(Sinapis arvensis L.), common beet (Beta vulgaris L.), sweet signal grass[Brachiaria eruciformis (Sm)] and Bermuda grass [Cynodon dactylon (L.)Pers.]. The results showed that the losses in grain yield of wheat, due toweeds competition, were 37%, 29% and 21% for seasons 2001/2002,2002/2003 and 2003/2004, respectively. The herbicide pendimethalin, atall rates tested, showed no phytotoxicity symptoms on wheat. The higherrates of oxadiazon and oxyfluorfen, however, showed slight phytotoxicityto the wheat crop. All herbicide treatments of Ronstar and Goal resultedin good to excellent control (72%–97%) of both grassy and broad-leavedweeds. The herbicide pendimethalin displayed excellent activity againstgrasses and poor to satisfactory activity (0%-67%) against broad-leavedweeds. The weed Cynodon dactylon tolerated all herbicide treatments.With the exception of Stomp, all herbicide treatments significantlyincreased wheat grain yield compared to the weedy check.

Efficacy of Pendimethalin Rates on Barnyard Grass (Echinochloa crus-galli (L.) Beauv) and Their Effect on Photosynthetic Performance in Rice

Pendimethalin herbicide toxicity to rice plants and barnyard grass invasion have increasingly affected the productivity of direct-seeded rice (DSR) in the fields. Whether and how to promote DSR productivity and sustain weed management depend on the appropriate pre-emergence herbicide application rate to minimise its toxicity in the rice ecosystem. Pot experiments were conducted to determine the effects of pendimethalin rates (1.5, 1.75, 2.0 kg a.i. ha−1, two control treatments include the untreated control and the treated control with 1.5 kg a.i. ha−1 S-metolachlor) on barnyard grass (Echinochloa crus-galli (L.) Beaux) and their potential toxicity risk to photosynthetic performances of rice (Topaz and Sen pidao). All the pendimethalin treatments provided excellent control of barnyard grass. Among the treatments, 1.5, 1.75, 2.0 kg a.i. ha−1 pendimethalin and 1.5 kg a.i. ha−1 S-metolachlor (treated control) decreased leaf area of barnyard grass significantly by 38.9, 49.6, 49.6 and 46.2%, respectively, compared with the untreated control at 40 days after sowing (DAS). The above-ground biomass of barnyard grass significantly decreased by 40% (1.48 g plant−1) with 2.0 kg a.i. ha−1 pendimethalin and by 46.2% (1.33 g plant−1) when 1.5 kg a.i. ha−1S-metolachlor was applied at 40 DAS compared with the untreated pots. Higher pendimethalin rates increased toxicity in Topaz and Sen pidao varieties, and 2.0 kg a.i. ha−1 pendimethalin significantly reduced effective quantum yield (light-adapted) of photosystem (PS) II by 18% (0.58) and 19% (0.52), respectively, compared with the untreated control. Application of 2.0 kg a.i. ha−1 pendimethalin rate significantly decreased the maximum quantum yield (dark-adapted) of Sen pidao (0.66) compared with 1.5 kg a.i. ha−1 pendimethalin (0.68) including the untreated control. All pendimethalin treatments suppressed above-ground biomass at 55 DAS, but above-ground biomass of barnyard grass significantly decreased by 59.9% when 2.0 kg a.i. ha−1 pendimethalin was applied compared with the untreated control. Although application of 1.5 kg a.i. ha−1 pendimethalin rates reduced the effective quantum yield (light-adapted) of photosystem II of Sen pidao (0.55) by a small percentage (8%) than Topaz (0.65), it was non-toxic for both varieties compared with 2.0 kg a.i. ha−1 pendimethalin. Therefore, the use of 1.5 kg a.i. ha−1 pendimethalin can be used for effective weed management in the direct seeding of rice at an early growth stage.

Effects of some control methods on Johnson grass and yield components in tomato fields

Johnson grass is one of the most dangerous and difficult to control weeds. The aim of this study was to determine the effect of different control methods on Johnson grass in tomato fields and to investigate the effect of these methods on the phenological stages and yield indicators of tomatoes. The study was carried out during the 2019 and 2020 seasons. The experiment treatments were as follows: hand hoe, mulch, preemergence herbicide pendimethalin (5 L/ha), postemergence herbicide fluazifop-P-butyl (1 L/ha), and control parcels. The number of flowers, the number of branches, and the length of the plant were determined in tomato. The yield and characteristics of the fruit were calculated and the fruits were analyzed. For Johnson grass, the time for germination, flowering, and seed maturity were determined. Plant height, fresh and dry biomass weight of weed, and rhizomes were also calculated. The results of this experiment showed that the best yield was 64.943 kg/ha in the hand hoe and the fluazifop-P-butyl treatment. The lowest density and fresh biomass of Johnson grass were detected in the fluazifop-P-butyl (217.3 stem/mm$^{2}$, 1009.4 g/m$^{2}$) and the mulch (251.7 stem/mm$^{2}$, 1355.2 g/m$^{2}$) treatments, respectively. The highest density and fresh biomass were detected in control parcels (448.8 stem/m$^{2}$, 3239.2 g/ m2), and in the pendimethalin treatment (334.2 stem/m$^{2}$, 1956.4 g/m$^{2}$), respectively. The percentage of lost yield in the control parcels was 90.1%. Hand hoe was found to be the most effective control method against Johnson grass followed by fluazifop-P-butyl, mulch, and pendimethalin.

Dualistic Fluorescence as Well as Portable Smartphone-Assisted RGB-Relied Sensing Assay for the Ultra-Sensitive Determination of Pendimethalin in Food and Water Samples by AIEE Active Organic Probes.

Herein, a peculiar fluorometric as well as smartphone-assisted RGB-relied sensing assay is introduced for determining pendimethalin (PDM) herbicide contents (in parts per trillion level) based on the anthracene-incorporated pyrimidinone/thione probes (S1 to S4). These compounds offered a unique and impressive aggregation-induced emission enhancement (AIEE) behavior by aggregation in H2O-dimethylformamide medium. Furthermore, these AIEE active compounds were found to display superior selectivity and extraordinary sensitivity for PDM detection via fluorescence quenching response. The extent of quenching degree was found to be linearly varied with the PDM concentration ranging from 0 to 20 nM, with a lower limit of detection of 367.8 pM (103.4 ppt) by S3 nanoaggregates. The detailed investigation revealed that such a high sensitivity of the designed sensor toward PDM is attributable to the existence of dual "photoinduced charge transfer and Förster resonance energy transfer process mechanisms". The Stern-Volmer plots, Job's plot, Benesi-Hildebrand plot, and 1H NMR titrations as well indicated the existence of substantial interactions between the sensor and PDM. The conducted selectivity tests provided distinguishable selectivity for PDM detection over various other insecticides/pesticides as well as other structural nitro analogues. Additionally, the presented sensing assay was also applied to quantify the PDM residues in spiked food (vegetables, fruits, and grains) and water samples. In addition, the sensor-coated fluorescent paper test strips were also fabricated for on-site detection of PDM. The applicability of smartphone-relied RGB analysis significantly streamlined the operation process, speeds up the detection procedure, and also offered a novel methodology for real-time analysis of PDM in real samples.

Hydrothermal synthesis of bifunctional Ag/MnO2 nanowires decorated with V2O5 nanorice: Photocatalytic and electrochemical impedance study for treatment of impurities present in waste water

Organic dyes and herbicides are harmful pollutants that are being increasingly found in the water systems. To treat these waste water pollutants effectively, photocatalysis can be applied as green and eco-friendly clean up technology. In this article, a novel binary composite consisting of Ag doped MnO2 nanowires (NWs) and V2O5 nanorice (NRs) in 1:1 ratio was synthesized for photocatalytic treatment of Congo red (CR) dye and Pendimethalin (PM) herbicide. Physiochemical properties of the composite were determined by XRD, FT-IR, and SEM spectroscopy. Results revealed that the robust interfacial interactions and generation of heterojunctions among Ag/MnO2 NWs and V2O5 NRs improved the electron-hole pair separation. Due to very low aspect ratio of Ag/MnO2 NWs and V2O5 NRs in the composite, Ag/MnO2@V2O5 provided a high surface area and increased the photocatalytic performance of photocatalyst. The photocatalytic efficiency of Ag/MnO2@V2O5 for the removal of CR was 82.9% 0.0142 min−1 that was ∼2.85 and ∼4.15 times higher than Ag/MnO2 and V2O5. In addition, Ag/MnO2@V2O5 showed 50.9% degradation of PM within 120 min with rate constant value of 0.005 min−1. When applied for cyclic test, Ag/MnO2@V2O5 exhibited excellent chemical and photostability. These results proved Ag/MnO2@V2O5 as potential photocatalyst for removal of various industrial and agriculture effluents. Electrochemical impedance spectroscopic (EIS) study was also carried out using three electrode measurements. The electrochemical data obtained showed that the Ag/MnO2@V2O5 has reduced charge transfer resistance and thus electrochemical measurements confirmed the excellent performance of prepared catalyst.

Modeling the Ability of a Maize–Olive Agroforestry System in Nitrogen and Herbicide Pollution Reduction Using RZWQM2 and Comparison with Field Measurements

Agricultural pollution models are a valuable tool for researchers and managers to predict and assess the potential contamination from the use of fertilizers and pesticides in the field. RZWQM2 is a comprehensive software package developed by the US EPA to predict environmental pollution after agrochemical application. The aim of the present study was to predict, using RZWQM2, the nitrogen and pesticides contents in soil of a monocrop and a tree-crop agroforestry system, and evaluate the effect of trees in reducing pollutants. Soil, weather, and agrochemical parameters for each setup were used as inputs in the model. Soil samples were collected at various depths and distances from the olive trees and were analyzed in the laboratory for nitrogen and pesticide contents. From the analysis of the results, it can be concluded that the model could identify the positive impact of the tree-crop agroforestry system in pollution reduction. Comparing the estimates with the relevant field data, the model presented some overestimation of the pesticide levels, particularly for the high-adsorptive and persistent pendimethalin herbicide, and slightly underestimated the concentrations of nitrates in the soil profile, while ammonium concentrations were well described. Overall, the model can be considered a useful and powerful tool for assessing the positive impacts of agroforestry systems in reducing soil pollution.

Bio‐efficacy of different post‐emergence herbicides in mungbean

AbstractWeeds result in a significant yield loss in mungbean (Vigna radiata[L.] R. Wilczek). However, post‐emergence (POST) herbicides are limited in mungbean for broad‐spectrum weed control. Therefore, we evaluated the efficacies of different herbicides in mungbean to find a suitable broad‐spectrum POST herbicide. Nine herbicides, weed‐free check, and unweeded control treatments were tested in a randomised block design with three replications for two consecutive years. Among the tested herbicides, clodinafop‐propargyl + sodium‐acifluorfen 122.5 g a.i. ha−1applied at 15 days after sowing (DAS) reduced the broad‐leaved weed dry weight at 35 DAS and harvest by 55.8% and by 58.6% (p < 0.05) compared with the unweeded control respectively. Notably, it minimised the total weed dry weight by 23.1%–30.3% compared with the recommended herbicide pendimethalin 1 kg a.i. ha−1– quizalopfop‐p‐ethyl 100 g a.i. ha−1(p ≤ 0.05). Clodinafop‐propargyl + sodium‐acifluorfen had higher weed control index (58.2% at 35 DAS and 62.1% at harvest) over the remaining tested herbicides. Unweeded controls resulted in 51% yield loss compared with the clodinafop‐propargyl + sodium‐acifluorfen that did not differ from pendimethalin − quizalofop‐p‐ethyl for seed yield of mungbean. Decreasing order of treatment efficacy on mean grain yield across two years comprised the weed‐free check, clodinafop‐propargyl + sodium‐acifluorfen and pendimethalin − quiza‐lofop‐p‐ethyl, imazethapyr + imazamox, tembotrione, and topramezone. [Correction added on 10 November 2022, after first online publication: In the preceding sentence, changes have been made to the article content to improve clarity in this version.] Application of clodinafop‐propargyl + sodium‐acifluorfen led to the greatest increase in soil microbial biomass carbon, indicating higher levels of soil biological and rhizospheric activity. We suggest that clodinafop‐propargyl + sodium acifluorfen is a suitable broad‐spectrum option for weed management of mungbean.

Mass Spectrometry-Based Peptide Profiling of Haemolymph from Pterostichus melas Exposed to Pendimethalin Herbicide

Pendimethalin-based herbicides are used worldwide for pre-emergence selective control of annual grasses and weeds in croplands. The endurance of herbicides residues in the environment has an impact on the soil biodiversity and fertility, also affecting non-target species, including terrestrial invertebrates. Carabid beetles are known as natural pest control agents in the soil food web of agroecosystems, and feed on invertebrates and weed seeds. Here, a mass spectrometry untargeted profiling of haemolymph is used to investigate Pterostichus melas metabolic response after to pendimethalin-based herbicide exposure. Mass spectrometric data are examined with statistical approaches, such as principal component analysis, for possible correlation with biological effects. Those signals with high correlation are submitted to tandem mass spectrometry to identify the associated biomarker. The time course exposure showed many interesting findings, including a significant downregulation of related to immune and defense peptides (M-lycotoxin-Ls4a, Peptide hormone 1, Paralytic peptide 2, and Serine protease inhibitor 2). Overall, the observed peptide deregulations concur with the general mechanism of uptake and elimination of toxicants reported for Arthropods.