Broad-leaved Weeds Research Articles

Effect of Nano Encapsulated Pendimethalin on Growth Attributes of Rice

Weed infestation is a major problem in upland rice of Kerala. Pendimethalin is a selective pre-emergent herbicide used to control broad-leaved and grassy weeds in rice fields. However, herbicides like pendimethalin often face losses in the agroecosystem through various pathways, reducing their effectiveness and potentially contaminating the environment, including groundwater. Encapsulation of herbicides is an innovative method designed to enhance their efficacy while minimizing environmental contamination, making herbicide application more efficient for weed control. A field experiment was carried out at the Instructional Farm, College of Agriculture, Vellayani, Kerala, India to evaluate the effect of different concentrations of Nano Encapsulated Pendimethalin (NEP) for weed management in upland rice. Synthesis of nano encapsulated pendimethalin was done at Department of Agronomy, College of Agriculture, Vellayani. The study revealed that nano encapsulated pendimethalin had significant influence on growth attributes over normal commercial formulations. Among all the growth parameters Nano Encapsulated Pendimethalin (NEP) with 4% starch aqueous phase at 1.0 kg ha-1 showed comparable result with hand weeding at 15 and 30 Days After Sowing (DAS). The nano encapsulated formulation had a particle size of 486.6 nm and zeta potential of -18 mV.

Herbicide Combinations for Effective Weed Management in Rice

Rice (Oryza sativa L.) is the most important food crop catering half of the world’s population. India being the second largest producer of rice, needs to produce around 120 million tons of rice by 2030 to feed its one and a half billion plus population. Weeds are undoubtedly a major biotic constraint to rice production in most of the rice growing areas of the world. Rice fields are very often characterized by a complex plurispecific weed flora, comprising of grasses, sedges, and broad-leaved weeds (BLWs). They usually grow faster than rice and absorb available water and nutrient earlier than the rice and suppress rice growth. Cultural and mechanical methods of weed management in general, are time consuming, cumbersome and laborious apart from being less effective because of chance of escape and regeneration of weeds from roots or rhizome that are left behind. Herbicides offer the most effective, economical and practical way of weed management. Since rice ecosystems usually harbours a variety of weeds, the use of a single herbicide cannot give satisfactory results. Moreover, continous use of such herbicides leads to the evolution of weeds resistant to several herbicides. Therefore, more convenient option would be single shot application of ready mix or tank mix combination of herbicide. The herbicide mixtures broaden the spectrum of weed control in single application. The ideal herbicide combinations are those that effectively target the weed species while minimizing toxicity to crops, thereby exhibiting enhanced selectivity. Using herbicide combinations allows for reduced herbicide use rates compared to using a single herbicide. Additionally, apart from providing broad-spectrum weed control, herbicide combinations reduce the herbicide load in the environment and minimize application costs. Among the various combination herbicides available, the ones having pre-emergence and post-emergence herbicides combined had shown better weed control with single shot application at reduced cost. Some of the ready-mix herbicide combinations that are gaining greater importance includes Pretilachlor + Pyrazosulfuron-ethyl, Pendimethalin + Penoxsulam and Butachlor + Penoxsulam.

Impact of Different Herbicidal Treatments on Hybrid Maize: A Review

Maize (Zea mays L.) is an important cereal crop grown in the world. The living factors (insects, pests, weeds) and non-living factors (drought, salinity, heat stress) affects the yield of maize; among which weeds are considered as most destructive in decreasing the maize crop yield. Weeds negatively affect the grain yield of maize and increase the production cost of farmers. Various herbicides are used to control weeds in maize including atrazine, tembotrione etc. Atrazine is a pre-emergence herbicide used to control weeds. It is a selective herbicide used to control broad-leaved weeds and annual grasses. Tembotrione is a PoE (Post-emergence) broad spectrum herbicide used to control broad-leaved and grassy weeds in maize. This herbicide effectively reduces the density and dry weight of most of the weeds present in maize crop. Tembotrione gives lower weed index and higher weed control efficiency, when applied at 150 g ha−1 + surfactant and 125 g ha−1 + surfactant at 20 DAS. These herbicide shows no phytotoxicity effect on the crops. They are totally safe for weed control and enhance the productivity and profatibilty of the crop.

Weed Management with New Generation Herbicides in Rabi Lentil in Sub-mountainous Area of Reasi District

In rabi, 2017–18, a field study was carried out at KVK, Reasi, SKUA&T, Jammu & Kashmir to assess the effectiveness of five herbicides applied alone, in combination with mechanical weeding (MW), or in sequence to study the effects of the herbicides on weed control and production economics of lentil variety L4147 (Pusa Ageti). Three replications of the experiment were conducted using completely randomized block design having six treatments with three replications. The treatments included T1:Weedy check (control), T2: Weed free, T3: Hand Weeding at 30 DAS and 45 DAS (Khurpi), T4: Quizalofop-p-ethyl 5% EC @ 50 g ai /ha at 40 DAS, T:5 Imazethapyr 10% SL at 40 DAS @ 37.5 g ai /ha, T6: Chlorimuron ethyl 25% WP (PPI) @ 4 g ai/ha and T7: Pendimethalin 30% EC (PE) @ 1 kg ai/ha. The most successful approach for controlling weeds, after weed free, was two hand weeding (HAND WEEDING), according to the results. However, at 60 DAS, two hand weedings at 30 DAS and 45 DAS produced the dry matter accumulation and lowest density of all weed species, followed by pendimethalin and Imazethapyr (post-emergence/POE). Under two hand weeding, the highest weed control efficiency of 83% was attained, and this was followed by Imazethapyr at 40 DAS. But under weed-free conditions, the maximum yield (1365 kg /ha) as well as the highest pods per plant (66.07), seeds per pod (1.94) and nodules per plant (8.20) were observed. Two hand weeding was then applied at 25 and 40 DAS. Pendimethalin greatly lowered broad leaved weeds but only moderately controlled grasses and sedges, while it was still better than control when applied alone. In contrast, Imazethapyr significantly suppressed both broad and grasses. When it came to the economic component, two-hand weeding outperformed all other treatments, including control, with the highest net returns, benefit cost ratio (~42294.49 /ha and 2.8), and lowest weed index (2.8). It was discovered that this combined treatment was the most profitable and long-lasting weed control method for lentils.

Significance of Insuring Herbicides for Stabilization of Weed Control Effectiveness and Quality when Using Betanals-Generics for Sugar Beet

In the field in 2014–2020, three-component herbicides of betanal generics were tested against juvenile dicotyledonous weeds in sugar beet crops to compare with the effectiveness of the use of the original herbicide Betanal Expert of (BEOF) at application rate of 1.0 l/ha. It is shown that the stability of dilute emulsions of generic betanals depended on the characteristics of the structure and dispersion of working solutions, the ability to crystallize active substances, and reactions to various environmental conditions. The BEOF herbicide in the application rate of 1.0 l/ha differed from generic betanals in the same application rate by a higher effect on weeds. The weeds that formed 2 real leaves showed phase resistance to generic betanals more noticeably. The effectiveness of BEOF on weeds in the cotyledon phase was 6–8% higher than that of generics, and 18% higher when treating weeds in the phase of 2 real leaves. It was found that in the temperature range of 19–22°C, the efficiency of generic betanals was closest to the efficiency of the original BEOF. To stabilize the generic betanals efficacy on weeds with the original BEOF 1.0 l/ha, their application rate was increased by 15–20%. A mixture of generic betanals with the insurance herbicides Mitron and Caribou, applied 3 times in the recommended application rates in accordance with the phase of development of sugar beet, provided high purity of sowing and crop yield at the level of the control group with manual weeding. Herbicides, in addition to broad-leaved dicotyledonous weeds, effectively suppressed young plants of aspens and field bindweed. The insurance herbicides Mitron and Caribou offset the disadvantages of generic betanals when used together in the fight against weeds in sugar beet crops.

Yellow mealworm frass: A promising organic fertilizer for common sowthistle (Sonchus oleraceus L.) and bristly oxtongue (Helminthotheca echioides (L.) Holub) cultivation

Common sowthistle (Sonchus oleraceus L.) and bristly oxtongue [Helminthotheca echioides (L.) Holub] are winter broad-leaved weeds that have gained interest for cultivation as leafy vegetables. The aim of this study was to examine the effects of frass from the yellow mealworm (Tenebrio molitor L.) on nutrient content in soil, growth parameters, and nutrient content in above-ground plant tissues of common sowthistle and bristly oxtongue. Thus, two pot experiments were carried out with 5 treatments [control, calcium ammonium nitrate (CAN) applied at a dose of 100 kg N ha−1, and insect frass applied at a rate of 3500 kg ha−1 (0.5 % w/w) 7000 kg ha−1 (1 % w/w), and 14,000 kg ha−1 (2 % w/w)]. Our results showed that the lowest values of growth parameters for both plant species were recorded in the control treatment. At the final rosette growth stage [e.g., 152 days after sowing (DAS)], the CAN treatment exhibited the highest values of rosette diameter and above-ground dry weight, followed by the highest rate of insect frass. Similarly, at 152 DAS the SPAD index values in the CAN treatment were 28.4–41.5 % higher compared to the control treatment in both species. Regarding root dry weight, the highest values were found in the CAN and insect frass 2 % treatments. In addition, the application of insect frass significantly enhanced soil fertility, with the highest levels of P and K recorded in the insect frass 2 % treatment. In contrast, the CAN treatment resulted in the highest NO3–N content in the soil (15.83 and 19.26 mg kg−1 in common sowthistle and bristly oxtongue, respectively). Moreover, both P and K content in the above-ground plant tissues had the highest values in the insect frass 2 % treatment, while the content of Mg, Mn, and Cu in plant tissues was not affected by the fertilization sources. Therefore, our findings indicate that insect frass can be an additional option in crop fertilization programs as it can improve both the soil fertility and growth of crops compared to conventional inorganic fertilizer sources. However, the effects of insect frass in mixtures with inorganic fertilizers needs to be taken into consideration in future studies.

Glucose-montmorillonite hydrochar composite activating peroxymonosulfate for sulfentrazone rapid degradation and phytotoxicity alleviation to rice

Sulfentrazone is an excellent herbicide for the control of broad-leaved weeds and some grasses. However, its herbicidal residues pose potential risks to the environment. The use of carbonaceous materials as catalysts for activating peroxymonosulfate (PMS) for managing pesticide contamination has attracted considerable attention. Herein, the rapid degradation of sulfentrazone in water and the alleviation of sulfentrazone-induced phytotoxicity alleviation to rice were investigated using glucose-montmorillonite hydrochar (GM-HC) activating PMS. The findings revealed that the GM-HC/PMS system can rapidly degrade sulfamethoxazole and achieved 93.90% of removal efficiency in 24 h. Specifically, GM-HC activating PMS generated the active species, including sulfate radicals (SO4•–), singlet oxygens (1O2) and superoxide radicals (O2•−), which speeds up the degradation of sulfentrazone. Five major degradation products of sulfentrazone and two possible degradation pathways were proposed. The C-Cl and C-CH3 of sulfentrazone molecules are the initiation sites attacked by active species for degradation according to density functional theory (DFT) calculation. Additionally, after the sulfentrazone was degraded by GM-HC/PMS system, sulfentrazone-induced phytotoxicity to rice seeds and seedlings was significantly alleviated. This work presents a novel approach for addressing herbicide wastewater pollution.Graphical

Effect of Planting Methods and Weed Control Treatments on Weed Dynamics, Yield and Economics of Green Gram (Vigna radiata L.)

An experiment was conducted at the Agronomy Research Farm, College of Agriculture, Gwalior (M.P.), during the 2019 kharif season to investigate the effects of different planting methods and weed control treatments on the weeds, growth, yield, and economics of green gram. The field experiment followed a split-plot design with three planting methods as main plot treatments (broadcasting on a flat bed, line sowing on a flat bed, and ridge and furrow) and five weed management practices as sub-plot treatments (Pendimethalin 1000 g/ha, Diclosulam 26 g/ha, Imazethapyr 75 g/ha, hand weeding at 20 and 40 DAS and weedy check), replicated thrice. The experimental field was primarily infested with narrow-leaved weeds such as Cyperus rotundus, Cynodon dactylon, Echinochloa spp., and Dactyloctenium aegyptium, and broad-leaved weeds like Digera arvensis, Celosia argentea, Commelina benghalensis, and Phyllanthus niruri. Among the herbicidal treatments, Imazethapyr at 75 g/ha effectively controlled both narrow-leaved and broad-leaved weeds, resulting in the lowest weed index. The ridge and furrow planting method recorded the highest values in growth parameters, yield attributes, and seed yield, proving to be more remunerative compared to other methods. These findings indicate that the combination of ridge and furrow planting with effective weed management, particularly using Imazethapyr, optimizes green gram productivity and economic returns.

Enantiomeric purity determination of lactofen formulations through Chemometric Deconvolution of partially overlapped chromatographic profiles

Lactofen is a chiral restricted-use herbicide, classified as toxicity class I by the Environmental Protection Agency (EPA), commonly used to control broadleaved weeds. While the observed herbicidal activity mostly derives from the (S)-(+)-enantiomer, formulations have been manufactured as a mixture of both enantiomers. In this work, we present a quantitative method for the enantiomeric determination of lactofen in commercial formulations based on the development of a second-order calibration to assist the selectivity of chiral separation under reversed-phase liquid chromatographic mode coupled to diode array detection. Chromatographic conditions were aimed to minimize analysis time and solvent consumption. This approach is feasible because second-order calibration allows for the quantification of overlapping bands and analytes in the presence of interferences. Chromatographic-spectral matrices were processed by unfolded partial least-squares coupled to residual bilinearization. The proposed methodology was evaluated through validation samples, achieving relative errors of predictions of 2–4 %. Finally, commercial formulations were subjected to minimal sample treatment and analyzed, and figures of merit for real samples were determined. The described methodology results suitable for the determination of enantiomeric purity and quality control in commercial lactofen formulations.

Time-Efficient Low-Resolution RGB Aerial Imaging for Precision Mapping of Weed Types in Site-Specific Herbicide Application

An efficient method for weed detection and the precise generation of spraying maps is crucial to optimising weed management strategies and minimising the costs associated with herbicide use. This study presents a method that leverages low-resolution UAV images to accurately detect and map weeds in sugarcane fields. The proposed approach integrates RGB images, vegetation indices and the HSV colour space, enhancing segmentation through histogram equalization (HE) and object-based image analysis (OBIA). The models developed in this study demonstrate exceptional performance in weed detection, with the most suitable dataset, achieving a detection capability of 95.78% for Broad-leaved Weeds (BLW) and the highest accuracy of 94.45% for Narrow-leaved Weeds (NLW). When considering multiple targets such as BLW, NLW, soil and sugarcane, the models exhibit a detection accuracy of 89.69%. Furthermore, the precision spraying maps generated by the coverage model method (CM) demonstrate remarkable accuracy, reaching 97.50% for weed control using agricultural drones. This method offers an efficient, cost-effective, and timely solution for precise weed detection, leading to improved weed control outcomes by enabling the selection of appropriate chemical substances tailored to each weed species. It reduces repetitive spraying costs and minimises chemical usage through spot spraying.

Occurrence and Mechanisms Conferring Multiple Resistance to ALS-Inhibiting and Auxins Mimics Herbicides in Papaver rhoeas from Tunisia

Herbicide-resistant corn poppy (Papaver rhoeas L.) is one of the most important broadleaved weeds and the number of resistant cases is still growing. The aims of this study were to confirm the resistance of P. rhoeas from Tunisia to ALS inhibitors and auxin mimics and investigate the mechanisms of Target-Site Resistance (TSR) and Non-Target Site Resistance (NTSR) involved. Dose–response trials to determine cross-resistance patterns for ALS inhibitors and auxin mimics were conducted in a greenhouse. In this study, multiple resistance to tribenuron-methyl and dicamba but not to 2,4-D was found in P. rhoeas populations. Cross-resistance to imazamox was confirmed as well. Sequence analysis of the ALS gene detected target-site mutations in codon 197 of the ALS gene, namely, Pro197His, Pro197Thr, Pro197Leu, and Pro197Asn. In this study, the metabolism experiments with malathion (a cytochrome P450 inhibitor) showed that malathion reduced resistance to imazamox, indicating that P450 is involved in the resistance. TSR and NTSR mechanisms to ALS inhibitors likely coexist. The findings of this study revealed a significant synergistic interaction between malathion and dicamba in particular populations, suggesting that the resistance to auxin mimics can be conferred by enhanced metabolism.

Weed Biology and Ecology Studies: Diversity, Dominance and Prediction of Yield Loss of Corn (Zea mays L.) Due to Broadleaf Weeds Competition in Dryland

The aim of the research was to determine the diversity, distribution, dominance, and yield loss of corn due to competition from broadleaf weeds. Descriptive research method with direct survey techniques of research objects. Data were collected using 10 sample plots measuring 1 m2, which were placed using random sampling. Observation parameters include the population and dry biomass weight of weeds and corn. The data was analyzed descriptively and comparatively by calculating density, frequency, and dominance to obtain an important value index and summation diminance ratio (SDR). The results of the research showed that 14 species of broad-leaved weeds were found with high species diversity, distribution, dominance, and abundance indices. The competitiveness and relative weighted dominance of six weed species, namely Amaranthus spinusus, Amaranthus gracilis, Synedrella nodiliflora, Acalypha indica, Ageratum conyzoides, and Alternanthera philoxeroides, are higher than those of other weed species, causing corn yield losses of 5.56%–21.90%. Therefore, these six weed species must be controlled.

Pyroxasulfone based tank-mix herbicide combinations for diverse weed flora control in wheat

Field studies were conducted to assess the efficacy of pyroxasulfone alone and its combinations with other herbicides at different time of application against a diverse weed flora in wheat (Triticum aestivum L). Applications of pyroxasulfone at 125 g/ha as pre-emergence (PE) or early post-emergence (EPO) at 20 days after sowing effectively controlled the grass weeds (Phalaris minor Retz. and Avena ludoviciana Durieu). However, pyroxasulfone alone exhibited poor control of broad-leaved weeds, such as Medicago denticulata Willd and Rumex dentatus L. To address the limitations in controlling broad-leaved weeds, tank mix combinations of pyroxasulfone at 125 g/ha with either pendimethalin at 1000 g/ha or metsulfuron at 4 g/ha or metribuzin at 300 g/ha proved highly effective. Pre-emergence pyroxasulfone application in combination with either metsulfuron (125 + 4 g/ha) or with metribuzin (125 + 300 g/ha) in wheat gave effective control of diverse weed flora and improved wheat productivity by 52.1% and 51.2%, respectively, over untreated control. Ready mix combination of clodinafop + metribuzin 60 + 210 g/ha applied as post emergence (32 DAS) provided >99% control of P. minor, A. ludoviciana, M. denticulata and R. dentatus L., however the phytotoxicity with this treatment produced 6.7% lower yield as compared to season long weed free conditions. Among the herbicidal treatments, pre-emergence application of pyroxasulfone + metsulfuron at 125 + 4 g/ha had the highest net returns followed by alone application of pre-emergence metribuzin at 300 g/ha.

Comparative Efficacy of Weed Management Practices on Grain and Straw Yields of Wheat

Wheat is central to Afghanistan's food security. It accounts for 76 percent of the annual grain cereal harvest and 57 percent of the country's total food crop production. Several factors, such as low-yielding varieties, low soil fertility, low-quality agrochemicals, widespread pest and disease infestations, and widespread distribution of weeds, are the leading causes of low wheat productivity in the country. The current study was conducted at the Student Research farm of the Faculty of Agriculture at Kabul University to determine the overall effects of weeds on wheat grain and straw yields and to evaluate and compare different weed management practices in the wheat field. After applying the weed management practices, among the treatments, T1, T3, and T4 showed only 8.3, 5, and 2.3 percent weed populations, respectively, compared to the untreated control. Regarding grain and straw yields, mechanical control (hand weeding) ranked first with a grain yield of 4,867 kg/ha, followed by T1 (4,580 kg/ha), T3 (4,513 kg/ha), T2 (4,133 kg/ha), and T5 (3,416 kg/ha), respectively. The difference in straw yield among the treatments was not significant; however, mechanical control ranked first (7,103 kg/ha), followed by T1 (6,783 kg/ha), T3 (6,700 kg/ha), T2 (6,207 kg/ha), and T5 (5,280 kg/ha), respectively. The study findings concluded that by eliminating weeds, wheat grain and straw yields could be increased by an average of 30 and 26 percent, respectively. As broad-leaved weeds are widely distributed in the wheat fields, applying relative herbicides such as 2,4-D is more effective and recommended for all cultivation methods.

Mapping weed infestation in maize fields using Sentinel-2 data

Weed management in maize farms is a time-specific activity and requires timely detection of weed infestations. The challenge to early detection of weeds is that many dicotyledonous crops and broad-leaved weeds often display similar reflectance profile in the early growth stage and requires hyperspectral data to detect them. However, the advent of Sentinel-2 sensor series, with enhanced spectral configuration featuring red-edge bands that are known for species-level discrimination of plants, presents an affordable opportunity to detect weeds using multispectral data. The present study explores the question of whether Sentinel-2 sensor with its advanced spectral configuration can differentiate weeds from maize (Zea mays) in the early growth stages of maize. The study recorded 165 GPS points of weeds, maize, and mixed class in six maize farms during the early stages of maize growth. These GPS points were overlaid on Sentinel-2 images acquired within two days of field data gathering to guide the collection of spectral signatures of the maize, mixed, and weed classes. Spectral signatures were divided into training (70%) and validation (30%) data in a Random Forest (RF) model with S-2 spectral bands and vegetation indices as predictor variables. Spectral signatures were firstly tested for spectral separability between classes using ANOVA. The results of spectral analysis showed that the weed class had higher interclass variability from the maize and mixed class particularly in the red-edge and NIR regions of Sentinel-2. The classification matrix consistently showed that weeds were detected with high user and producers’ accuracy of 95%. These results indicate the utility of the enhanced spectral configuration of Sentinel-2 data in the early detection of weeds in maize farms.

Weed science research achievements on maize in Ethiopia: a review

Recent research into assessing and combatting maize weeds was reviewed based on scientific and working reports from the year 2011 onwards in Ethiopia. This review paper covered two main topics: assessment of major weed types and their impacts, and research results of weed management in the maize cropping system of the country. More than 80 major weed floras dominated by broad leaved weeds were found infesting maize fields in different localities. By competing, toxifying and/or parasitizing maize plants, they reduce the crop germination, growth and productivity. Several experiments indicated that maize yield loss due to uncontrolled weed growth varied from 35 to 87.5%, indicating that weed management is a critical factor for maize production in the country. Hoeing, hand weeding and pre-emergence herbicides application have been the most frequently used weed control practices to minimize the competition effect of weeds. So far, there has been no effective and sustainable individual weed control method for maize fields. Thus, future research should focus on developing integrated weed management that effectively reduce weed infestation and associated impacts, and improve productivity of the crop considering socio-economic condition of a specific maize producing agro-ecology of the country.

Influence of Weed Management Practices and Biochar on Weed Dynamics of Fenugreek (Trigonella foenumgraecum L.)

A field experiment was conducted at Instructional farm, Rajasthan College of Agriculture, MPUAT, Udaipur (Rajasthan) during rabi season 2021-22 and 2022-23 to study the influence of weed management practices and biochar on weed dynamics of fenugreek. The experiment consists of eight weed management treatments and three biochar levels thereby involving 24 treatment combinations replicated thrice in factorial randomized block design. The pooled results revealed that pre-emergence application of oxyfluorfen 120 g ha-1 recorded significantly lowest density and dry matter of narrow-leaved, broad-leaved and total weeds and highest weed control efficiency (78.28%).

Efficacy of Tribinuron–methyl, Fluroxypyr and their Combinations in Controlling Broad-Leaved Weeds in Wheat

Efficacy of Tribinuron–methyl, Fluroxypyr and their Combinations in Controlling Broad-Leaved Weeds in Wheat

Effects of Herbicides and Nano Urea Mixture on Weeds, Yield Attributes and Yield of Wheat (Triticum aestivum)

Wheat (Triticum aestivum) is second most important staple crop in India after rice. Weeds have emerged as the major biotic stress in wheat. Post-emergence herbicidal combinations are used widely to control the complex weed flora in wheat crops. A field experiment was carried out to study the “Effects of herbicides and nano urea mixture on weeds, yield attributes and yield of wheat (Triticum aestivum)”. The experiment was performed in randomized blocked design with three replications and fourteen treatments in Rabi season 2022-23 at Agronomy Research Farm, CCS Haryana Agricultural University, Hisar. Significantly minimum weed count (1.52 m-2) and dry weight (1.49 g m-2) and maximum weed control efficiency (88.6%) of Phalaris minor and broadleaved weeds (87%) was recorded with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1 at 90 DAS. In case of yield attributes i.e. number of effective tillers per meter row length (92.5), spike length (11.4 cm), number of grains spike-1 (55.9) and 1000-grain weight (43.8) were higher with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1. Grain yield (5876 kg ha-1) and B:C (1.94) was recorded higher with application of clodinafop + metribuzin 60 + 210 g ha-1 with nano urea 3 ml L-1 followed by clodinafop + metribuzin 60 + 210 g ha-1 which was significantly higher than weedy check but at par with the weed free treatment.

Uptake, translocation, accumulation, and metabolism of fluroxypyr-meptyl and oxidative stress induction in rice seedling.

Fluroxypyr-meptyl (FLUME) is heterocyclic herbicide with internal absorption and transmission characteristics. Owing to its low cost and rapid efficacy, it has been widely used to control broad-leaved weeds in wheat, corn, and rice fields. However, the uptake, translocation, accumulation, and metabolism of FLUME in rice seedlings and the extent of oxidative stress induced by it remain largely unknown, which consequently restricts the comprehensive risk assessment of FLUME residues in the environment during rice production. Hence, we systematically investigated the growth and physiological responses of rice to FLUME and analyzed its uptake, translocation, accumulation, and metabolism in rice seedlings. The results indicated that under 0-0.12 mg/L FLUME treatment, only a small proportion of FLUME was translocated upward and accumulated in rice shoots following absorption via roots, with all the translocation factor values being < 1. Moreover, the distribution and enrichment ability of FLUME in rice seedlings were greater in roots than in shoots. Furthermore, we revealed that FLUME accumulation in rice seedlings evidently inhibited their growth and activated the defense system against oxidative stress, with an increase in the activity of antioxidant and detoxifying enzymes. In addition, multiple metabolic reactions of FLUME were observed in rice seedlings, including dehalogenation, hydroxylation, glycosylation, acetylation, and malonylation. Our study provides systematic insights into the uptake, translocation, accumulation, and metabolism of FLUME in rice seedlings as well as the oxidative stress induced by FLUME accumulation, which can help improve FLUME applications and environmental risk assessments in crops.