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The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Italy, and co‐rapporteur Member State, Poland, for the pesticide active substance penoxsulam are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of penoxsulam as a herbicide on rice and chicory. The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified. [ABSTRACT FROM AUTHOR]

Grass damage has become an important factor restricting foxtail millet production; chemical weeding can help resolve this issue. However, special herbicides in foxtail millet fields are lacking. Penoxsulam has a broad weed control spectrum and a good control effect. In this project, Jingu 21 was used as the test material, and five different concentrations of penoxsulam were used for spraying test in the three–five leaf stage. In this experiment, the effects on the growth of foxtail millet were discussed by measuring the agronomic characters and antioxidant capacity of foxtail millet after spraying penoxsulam. The results showed that: (1) penoxsulam is particularly effective in controlling Amaranthus retroflexus L. (A. retroflexus) and Echinochloa crus-galli (L.) Beauv. (E. crus-galli), but is ineffective in controlling Chenopodium album L. (C. album) and Digitaria sanguinalis (L.) Scop. (D. sanguinalis); (2) the stem diameter, fresh weight, and dry weight of the above-ground parts decreased with the increase in spraying amount; (3) as the spraying dosage increased, the superoxide (SOD), peroxidase (POD), and catalase (CAT) activities in the foxtail millet initially increased and subsequently decreased; the malonaldehyde (MDA) content increased. Our experiment found that 1/2X and 1X spraying dosages had certain application value in controlling gramineous weeds in foxtail millet field. Other spraying dosages are not recommended as they may harm the crops. Our findings provide reference for identifying new herbicides in the foxtail millet field. [ABSTRACT FROM AUTHOR]

Recently, due to the widespread use of the acetolactate synthase (ALS)-inhibiting herbicide penoxsulam in paddy fields in China, Echinochloa crus-galli (L.) P. Beauv. has become a problematic grass weed that is frequently not controlled, posing a threat to weed management and rice yield. There are many reports on target-site mutations of ALS inhibiting herbicides; however, the detailed penoxsulam resistance mechanism in E. crus-galli remains to be determined. Greenhouse and laboratory studies were conducted to characterize target-site resistance mechanisms in JL-R, AH-R, and HLJ-R suspected resistant populations of E. crus-galli survived the field-recommended dose of penoxsulam. The whole-plant dose–response testing of E. crus-galli to penoxsulam confirmed the evolution of moderate-level resistance in two populations, JL-R (9.88-fold) and HLJ-R (8.66-fold), and a high-level resistance in AH-R (59.71-fold) population. ALS gene sequencing identified specific mutations in resistant populations, including Pro-197-His in ALS1 for JL-R, Trp-574-Leu in ALS1 for AH-R, and Pro-197-Leu in ALS2 for HLJ-R. In vitro ALS activity assays demonstrated a significantly higher activity in AH-R compared to the susceptible population (YN-S). Molecular docking studies revealed that Trp-574-Leu mutation primarily reduced the enzyme’s ability to bind to the triazole-pyrimidine ring of penoxsulam due to decreased π–π stacking interactions, while Pro-197-His/Leu mutations impaired binding to the benzene ring by altering hydrogen bonds and hydrophobic interactions. Additionally, the Pro-197-His/Leu amino acid residue changes resulted in alterations in the shape of the active channel, impeding the efficient entry of penoxsulam into the binding site in the ALS protein. The three mutant ALS proteins expressed via the Bac-to-Bac baculovirus system exhibited notably lower activity inhibition rates than the non-mutant ALS proteins to penoxsulam, indicating all three ALS mutations reduce sensitivity to penoxsulam. This study elucidated the distinct impacts of the Pro-197-His/Leu and Trp-574-Leu mutations in E. crus-galli to penoxsulam resistance. Notably, the Trp-574-Leu mutation conferred stronger resistance to penoxsulam compared to the Pro-197-His/Leu mutations in E. crus-galli. The Pro-197-His/Leu mutations were first detected in E. crus-galli conferring penoxsulam resistance. These findings provide deeper insights into the molecular mechanisms underlying target-site resistance to penoxsulam in E. crus-galli.

Abstract The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Italy, and co‐rapporteur Member State, Poland, for the pesticide active substance penoxsulam are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of penoxsulam as a herbicide on rice and chicory. The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Foxtail millet planting has a long history and profound role in agricultural civilization. However, weeds have become one of the obstacles restricting the development of the foxtail millet industry. Penoxsulam, as an early post-emergence herbicide for controlling gramineous weeds in paddy fields, is effective for some broadleaf weeds. In this study, six different doses (CK, 0.5X, 1X, 2X, 3X, 4X) of penoxsulam were sprayed at the 3–5 leaf stage of the conventional variety Jingu 21 to study its effect on the growth and development of foxtail millet, in order to screen out the appropriate spraying concentration. The main results are as follows: Within 15 days after spraying penoxsulam, the plant height and leaf area of foxtail millet decreased with the increase in spraying dose, and gradually recovered 15–25 days after spraying, but there were still significant differences compared with CK. The photosynthetic pigment content, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), the maximum photochemical efficiency (Fv/Fm), photosynthetic system II actual photochemical efficiency (Y(II)), and photochemical quenching coefficient (qP) of foxtail millet decreased with an increase in the penoxsulam spraying dose, while the intercellular CO2 concentration (Ci) and non-photochemical quenching coefficient (NPQ) showed an upward trend. There was almost no significant difference in each index between the spraying dose of 0.5X and 1X and CK, but the photosynthesis of foxtail millet leaves was still significantly inhibited under a spraying dose of 3X and 4X. Penoxsulam had certain growth-inhibiting effects on Echinochloa crus-galli (L.) Beauv. (E. crus-galli), Digitaria sanguinalis (L.) Scop. (D. sanguinalis), Chenopodium album L. (C. album), and Amaranthus retroflexus L. (A. retroflexus) which increased as the spraying dosage increased. Our study found that spraying dose groups of 0.5X and 1X penoxsulam were safe for foxtail millet growth and could be used to control gramineous weeds in fields. Other spraying doses are not recommended in the field due to their serious phytotoxicity to foxtail millet, which provides a new measure for weed control in foxtail millet fields. [ABSTRACT FROM AUTHOR]

Objective: To establish a new QuEChERS-ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the detection of chlorantraniliprole and penoxsulam residues in rice. Methods: After the sample was extracted with 0.2% formic acid-acetonitrile, purified with N-propylethylenediamine (PSA) and graphitized carbon black (GCB) packing, 0.2% formic acid water and acetonitrile were used as mobile phases for gradient elution, and then subjected to C18 chromatography. UPLC-MS/MS was used to column separation and determination. Results: The limits of quantification (LOQ) of chlorantraniliprole and penoxsulam were both 0.004 mg/kg, and the method detection limits (LOD) were both 0.001 mg/kg. Chlorantraniliprole and penoxsulam had a good linear relationship in the range of 0.002~0.5 mg/L, and their coefficient was greater than 0.993. At the addition levels of 0.05, 0.1, and 0.5 mg/kg, the average recovery rates of chlorantraniliprole and penoxsulam were 86% to 110% with the relative standard deviations (RSD) of 1.5% to 6.1%. Conclusion: This method is efficient and simple, has good stability and high sensitivity, and is suitable for the detection of chlorantraniliprole and penoxsulam in rice.

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Grass damage has become an important factor restricting foxtail millet production; chemical weeding can help resolve this issue. However, special herbicides in foxtail millet fields are lacking. Penoxsulam has a broad weed control spectrum and a good control effect. In this project, Jingu 21 was used as the test material, and five different concentrations of penoxsulam were used for spraying test in the three–five leaf stage. In this experiment, the effects on the growth of foxtail millet were discussed by measuring the agronomic characters and antioxidant capacity of foxtail millet after spraying penoxsulam. The results showed that: (1) penoxsulam is particularly effective in controlling Amaranthus retroflexus L. (A. retroflexus) and Echinochloa crus-galli (L.) Beauv. (E. crus-galli), but is ineffective in controlling Chenopodium album L. (C. album) and Digitaria sanguinalis (L.) Scop. (D. sanguinalis); (2) the stem diameter, fresh weight, and dry weight of the above-ground parts decreased with the increase in spraying amount; (3) as the spraying dosage increased, the superoxide (SOD), peroxidase (POD), and catalase (CAT) activities in the foxtail millet initially increased and subsequently decreased; the malonaldehyde (MDA) content increased. Our experiment found that 1/2X and 1X spraying dosages had certain application value in controlling gramineous weeds in foxtail millet field. Other spraying dosages are not recommended as they may harm the crops. Our findings provide reference for identifying new herbicides in the foxtail millet field.

Ukraine is one of the world’s guarantors of food security and has the potential to further increase agricultural production. However, the vast majority of herbicides used on crops are acetolactate synthase (ALS) inhibitors, which poses a threat of herbicide-resistant weed species. The emergence and spread of herbicide-resistant weed biotypes can significantly increase the cost of growing crops to the point of loss of profitability. Herbicide resistance in barnyardgrass (Echinochloa crus-galli var. crus-galli) has been studied in long-term field and greenhouse experiments. Resistance of E. crus-galli to the ALS herbicide triazolopyrimidine derivative ‒ penoxsulam was identified. Expressed resistance was observed in weed plants grown from seeds collected under production conditions in Kherson region in 2015–2016 and 2020–2021. Cross resistance was observed for imidazolinone and sulfonylurea derivatives. It should be noted that the level of cross resistance to ALS herbicides was slightly higher for plants derived from weed seeds harvested in 2020–2021 compared to those harvested in 2015–2016. The introduction of a herbicidal composition of a herbicide mixture ‒ an inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD) (an enzyme in plants in the chain of carotenoid synthesis) ‒ mesotrione with an ALS-inhibitor (nicosulfuron) allowed effective control of the weed, which indicates the absence of multiple resistance to herbicides ‒ inhibitors of carotenoid synthesis. The high efficiency of E. crus-galli control was established by the application of herbicides ‒ inhibitors of fatty acid synthesis (graminicides). The highest level of efficiency in the experiments was observed with the application of fluazifop-butyl and somewhat less ‒ with pinoxaden. A tendency to reduce phytotoxicity to barnyardgrass from the south of Ukraine was observed with the introduction of tepraloxydim and quizalofop-ethyl. A lower level of phytotoxicity of fenoxaprop-p-ethyl on E. crus-galli should be noted compared to the effect of pinoxaden. No multiple resistance was observed with glyphosate (5-enolpyruvylshikimate-3-phosphate synthase inhibitor) and reglone (photosystem I inhibitor), allowing control of vegetative weeds at the beginning and end of the growing season. It has been established that monocot weed species have significantly increased their presence and harmfulness in agrophytocenoses in Ukraine and in the world since the 1950s with the widespread introduction of selective dicotyledonous species control with aryloxyphenoxyacetic, propionic and benzoic acid derivatives. This trend has been maintained until recently ‒ barnyardgrass is one of the dominant weed species in modern agrophytocenoses of Ukraine. Therefore, the identification of the ALS-resistant biotype of barnyardgrass complicates weed control in the following crops in rotations in the southern regions of the country: in maize crops with cross resistance to nicosulfuron, in sunflower ‒ to imidazolinones (imazamox, imazapyr), and also makes it impossible to use penoxsulam in rice production. Traditionally, the use of synthetic auxins, phenoxyacetic acid derivatives, etc. is used to control ALS-resistance. However, in Kherson region of Ukraine, already in the third year of application of rinskor (florpyrauxifen-benzyl), some weed plants were found on rice fields affected by ALS-resistant barnyardgrass, which recovered after the use of synthetic auxin. Therefore, the control of ALS-resistance (penoxsulam, etc.) in E. crus-galli with the application florpyrauxifen-benzyl in the Kherson region of Ukraine is already limited. An obvious and economically feasible preventive measure against the emergence of resistant weed biotypes is the implementation of GAP (Good Agricultural Practice, FAO) approaches: in particular, the use of high quality seeds without weed impurities, increasing the proportion of agrotechnical weed control measures, restoring and expanding crop rotations with mandatory rotation of herbicides with different modes of action, introducing dicotyledonous/leguminous crops into rotations, and using herbicides with different modes of action in crops separately or in mixtures. At the same time, agrotechnical measures and the preservation of biodiversity in agrophytocenoses should be the main factor in controlling resistance in weeds. The use of herbicides and their mixtures with different modes of action is of secondary importance. The identification of highly damaging ALS-resistant E. crus-galli in southern Ukraine indicates the insufficient effectiveness of weed control exclusively with herbicides with a single mechanism of action and requires a significant revision of the principles of crop rotation and ways of weed control in the country to maintain high levels of profitability and productivity of agrophytocenoses. Solving this problem is urgent for the preservation of Ukraine's potential as one of the guarantors of global food security.

Penoxsulam is an acetolactate synthase (ALS)-inhibiting herbicide usually applied by post-emergence foliar spraying (PFS) for the control of Echinochloa crus-galli and numerous annual weeds in paddy fields. Herbicides applied by foliar spraying can have negative impacts on the environment, ecosystems, and human health. In this study, the response of E. crus-galli and rice to the PFS and post-emergence water-dispersal (PWD) applications of penoxsulam, and the differences in the detoxification displayed by them between the two treatment methods were compared. The results showed that the PWD application of penoxsulam provides a similar control efficacy against E. crus-galli as PFS at the 1-, 3-, and 5-leaf stages. Meanwhile, the PWD application had a higher safety for the rice. After being treated with 30 g a.i. ha−1 penoxsulam, residues were not detected in the rice treated by the PWD application method, whereas, with the PFS treatment, there was 59.0 µg/kg penoxsulam remaining. With the PFS application, there were many more residues of penoxsulam in the E. crus-galli than with the PWD method; the amount of residues was 32-fold higher 12 h after treatment. The in vitro enzyme activity assays revealed that the activities of ALS, glutathione-S-transferase (GST), and cytochrome P450 monooxygenases (P450) were increased in the PWD treatments, and were 1.5-, 1.3-, and 2.3-fold higher than with PFS 72 h after treatment. The real-time quantitative PCR (qRT-PCR) revealed that the GST1 and P450 genes, CYP81A14, CYP81A12, CYP81A18, and CYP81A21 were upregulated with the PWD application versus PFS in the E. crus-galli. In summary, these results demonstrate that the herbicidal activity was not affected by the upregulation of target and metabolic enzyme activities with the PWD application of penoxsulam. This research could contribute to application strategies reducing the risk of rice injury and environmental impacts by using water-dispersal formulations of penoxsulam. [ABSTRACT FROM AUTHOR]

Threespike goosegrass (Eleusine tristachya) is a difficult-to-control perennial grass of increasing concern for orchard production systems in the Central Valley of California, USA. This grass has a bunch-type growth habit when tillered, which can interfere with orchard operations, particularly nut pickup from the ground at harvest. From 2016 to 2019, herbicide efficacy on threespike goosegrass was evaluated in a walnut (Juglans regia) orchard in Chico, CA, USA; an almond (Prunus dulcis) orchard in Livingston, CA, USA; and a prune (Prunus domestica) orchard in Orland, CA, USA. At each location, two independent experiments were conducted to evaluate 12 preemergent (PRE) herbicide treatments and eight postemergent (POST) treatments over several years, for a total of 16 trials. PRE herbicides were applied in January according to the region’s typical winter orchard management practices. One treatment included an additional sequential application in March to extend residual activity later into the warm season when threespike goosegrass germinates or resumes growth. In separate studies, POST control of established stands of threespike goosegrass was evaluated in May and June of each year. Each trial was conducted in a randomized complete block design with four replications. Threespike goosegrass control was visually estimated monthly for 5 months after the PRE treatments or at weekly intervals for 5 weeks following POST treatments. The most effective PRE treatment was a sequential application of indaziflam in January, followed by a March application of pendimethalin, providing 90% or greater control of threespike goosegrass 5 months after treatment across all sites and all years. Of the POST treatments, the three graminicides outperformed the other treatments with 73% to 91% control overall sites and years at 5 weeks after treatment. Fluazifop had the highest control ratings (85% to 91%) among the graminicide herbicides but was not always statistically better than clethodim or sethoxydim (74% to 83% control). Glyphosate alone resulted in unacceptable control (33% to 51%) regardless of rates tested, experimental sites, or years. Together, these results confirm grower reports of poor glyphosate performance on threespike goosegrass but suggest that effective herbicide programs can be developed to manage threespike goosegrass using PRE herbicides and POST graminicides registered in California orchard crops.

Oil dispersible suspension concentrates are safe, green, and environmentally friendly formulations. Problems such as layering, pasting, and bottoming are frequently encountered during the production, storage, and transportation process. Polyisobutylene succinimide functions as a dispersant and exhibits great potential to improve the physical stability of the oil dispersible suspension concentrate. From a microscopic perspective, the sorption characteristics of the polyisobutylene succinimide dispersant T151 on penoxsulam particle surfaces were comprehensively evaluated with XPS, FTIR, and SEM. The T151 adsorption procedure complied with a pseudo- second-order kinetic adsorption model, and it was a kind of physical sorption with an Ea of 22.57 kJ·mol-1. The T151 sorption model was consistent with the Langmuir isotherm. The adsorption process was spontaneous and followed by an entropy increase. The ΔHθ of dispersant T151 on the surface of penoxsulam particles was 31.59 kJ·mol-1. The adsorption procedure was endothermic, and the primary force was hydrogen bonding. The XPS results showed that the F and S electronic peaks at the penoxsulam interface decreased, and that the C electronic peak increased significantly after the adsorption of dispersant T151, indicating the adsorption on the surface of penoxsulam particles. The results of this study provide a vital theoretical basis for the application of polyisobutylene succinimide dispersants in oil dispersible suspension systems. [ABSTRACT FROM AUTHOR]

Rice yield in Southern Brazil has increased linearly over the years. Early season sowing is the primary contributor to rice yield increase in Southern Brazil. However, that practice might expose rice seedlings to the risk of low-temperature stress, which can enhance herbicide injury and reduce rice yield. This research evaluated the effect of sowing dates on herbicide selectivity and agronomical rice traits. We conducted field experiments during the 2010/11 and 2011/12 growing seasons in Capão do Leão, RS, Brazil. The experimental design was a complete randomized block with a factorial arrangement. Factor A was early-sowed (in September) and late-sowed (in November); factor B was herbicide treatment (bispyribac-sodium, cyhalofop-butyl penoxsulam, metsulfuron-methyl, and nontreated check). Rice response to herbicide treatments differed between years. In 2010/11, bispyribac-sodium, penoxsulam, and metsulfuron-methyl injured rice only on early-sowed. In both years, early sowing rice promoted higher yield potential despite herbicide injury. The injury caused by the herbicides bispyribac-sodium, penoxsulam and metsulfurom-methyl was transient did not lead to yield losses. Cold temperature close the application increases the injury of ALS herbicides. [ABSTRACT FROM AUTHOR]

Foxtail millet planting has a long history and profound role in agricultural civilization. However, weeds have become one of the obstacles restricting the development of the foxtail millet industry. Penoxsulam, as an early post-emergence herbicide for controlling gramineous weeds in paddy fields, is effective for some broadleaf weeds. In this study, six different doses (CK, 0.5X, 1X, 2X, 3X, 4X) of penoxsulam were sprayed at the 3–5 leaf stage of the conventional variety Jingu 21 to study its effect on the growth and development of foxtail millet, in order to screen out the appropriate spraying concentration. The main results are as follows: Within 15 days after spraying penoxsulam, the plant height and leaf area of foxtail millet decreased with the increase in spraying dose, and gradually recovered 15–25 days after spraying, but there were still significant differences compared with CK. The photosynthetic pigment content, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), the maximum photochemical efficiency (Fv/Fm), photosynthetic system II actual photochemical efficiency (Y(II)), and photochemical quenching coefficient (qP) of foxtail millet decreased with an increase in the penoxsulam spraying dose, while the intercellular CO2 concentration (Ci) and non-photochemical quenching coefficient (NPQ) showed an upward trend. There was almost no significant difference in each index between the spraying dose of 0.5X and 1X and CK, but the photosynthesis of foxtail millet leaves was still significantly inhibited under a spraying dose of 3X and 4X. Penoxsulam had certain growth-inhibiting effects on Echinochloa crus-galli (L.) Beauv. (E. crus-galli), Digitaria sanguinalis (L.) Scop. (D. sanguinalis), Chenopodium album L. (C. album), and Amaranthus retroflexus L. (A. retroflexus) which increased as the spraying dosage increased. Our study found that spraying dose groups of 0.5X and 1X penoxsulam were safe for foxtail millet growth and could be used to control gramineous weeds in fields. Other spraying doses are not recommended in the field due to their serious phytotoxicity to foxtail millet, which provides a new measure for weed control in foxtail millet fields.

Effective broad-spectrum herbicides are needed to address the issues of herbicide resistance and weed shifts in common cropping systems. A field experiment was conducted in 2016 and 2017 in West Bengal, India to compare the performance of three post-emergence herbicides (bispyribac-sodium; fenoxaprop-p-ethyl; penoxsulam) in monsoon rice (Oryza sativa L.) and their residual effects on succeeding rapeseed (Brassica rapa L.). Rice yield loss due to competition with Echinochloa colona (L.) Link, Leersia hexandra Sw., Cyperus iria L., Ludwigia parviflora L., and Monochoria vaginalis (Burm f.) C. Presl. Ex Kunth was 64% compared with weed-free control. Bispyribac-sodium 10% SC applied at 30 g a.i. ha−1 20 days after transplanting reduced weed density over the weedy control, ranging from 37% (M. vaginalis) to 87% (L. hexandra). Fenoxaprop-p-ethyl and penoxsulam applied, respectively, at 86 and 20 g a.i. ha−1 were effective in controlling grasses, but less effective against sedges and broadleaves. Bispyribac-sodium application resulted in highest rice yield (5.45 t ha−1), net return (Indian Rupees 42,677 ha−1), and benefit cost ratio (1.72). Bispyribac-sodium had neither adverse effect on soil microbes nor phytotoxic effect on rice and subsequent rapeseed. We recommend bispyribac-sodium for weed control in transplanted rice under rice-rapeseed system in eastern India. [ABSTRACT FROM AUTHOR]

A simple, efficient and cost-effective ultrasound-assisted extraction method for the quantification of penoxsulam, anilofos, bispyribac sodium, butachlor and pretilachlor from soil and rice was developed and validated. Three independent variables, including ultrasonication temperature, ultrasonication time, type and volume of solvent, were studied by single-factor experiments. Box–Behnken design (BBD) was also used to determine the optimal parameters for efficient extraction of penoxsulam, anilofos, bispyribac sodium, butachlor and pretilachlor herbicides from soil and rice. Under optimum conditions, the mean percent recoveries ranged from 82.1 ± 3.32 to 93.8 ± 2.56 from soil and rice grain with relative standard deviation <10% and limit of quantification less than the maximum residue limits imposed by principal regulatory agencies. Results depicted that the experimental values were consistent with the predicted values, indicating that RSM is accurate and reliable method to find the optimal UAE extraction conditions for studied herbicides from soil and rice. Furthermore, the greenness was evaluated using AGREE metrics, and UAE was found to be a greener and efficient method for the determination of herbicides from soil and rice. The developed method was extended to the analysis of real samples and concentration of herbicides at 0 day in soil samples varied from 0.483 ± 1.65 to 1.420 ± 1.41 µg g−1. At harvest, the concentrations of herbicides in soil and rice were below the permissible limit (<0.01 µg g−1). [ABSTRACT FROM AUTHOR]

A field experiment was conducted at the Research Farm, Institute of Agricultural Sciences, SOA, Bhubaneswar during Kharif, 2019. The experiment was laid out in split-plot design with three replications. The treatment comprised of three nitrogen levels (30, 60 and 90 kg ha-1) assigned in the main plot and six weed management practices viz., penoxsulam + cyhalofop butyl @ 125 g ha-1 at 20 DAT fb one hand weeding at 40 DAT, penoxsulam + cyhalofop butyl @ 125 g ha-1 at 20 DAT, bispyribac sodium @ 25 g ha-1 at 20 DAT fb one hand weeding at 40 DAT, bispyribac sodium @ 25 g ha-1 at 20 DAT, two hand weeding at 20 & 40 DAT, weedy check were assigned in the sub plot. The soil of the experimental site was sandy loam in texture with pH value of 5.7. Application of 90 kg N ha-1 recorded highest grain and straw yield and it was at par with application of 60 kg N ha-1. Among the weed management practices two hand weeding recorded the highest grain yield (5.01 t ha-1) followed by penoxsulam+cyhalofop butyl fb one hand weeding (4.81 t ha-1). The nitrogen level of 90 kg N ha-1 along with post-emergence application of penoxsulam+cyhalofop butyl @ 125 g/ha registered highest net return of Rs. 53,976 ha-1 and Rs. 53,569 ha-1, respectively with B:C ratio of 2.23 in each case. [ABSTRACT FROM AUTHOR]

Echinochloa phyllopogon is a noxious weed that can harm rice over prolonged periods. Recently, a penoxsulam-resistant variant of E. phyllopogon with a mutation in the acetolactate synthase (ALS) gene was collected in Northeastern China. In the present study, the molecular mechanism underlying herbicide resistance in mutant populations was evaluated. The GR 50 and IC 50 values of the herbicide-resistant mutant 1–11 were 27.0- and 21.4-fold higher than those of the susceptible population 2–31, respectively. In addition, pre-application of malathion reduced the GR 50 value of the resistant population. Additionally, mutant populations developed cross-resistance to other ALS inhibitors. E. phyllopogon ALS sequencing showed a Trp-574-Leu mutation in ALS2 variant 1–11. Molecular docking showed that the Trp-574-Leu substitution reduced the number of hydrogen bonds and altered the interaction between penoxsulam and ALS2. Transgenic Arabidopsis plants harboring the ALS2 mutant gene also showed resistance to penoxsulam and other ALS inhibitors. Overall, our study demonstrated that the Trp-574-Leu mutation and P450-mediated metabolic resistance lead to the cross-resistance of E. phyllopogon to ALS inhibitors. [Display omitted] • Target-site resistance of Echinochloa phyllopogon to ALS inhibitor was investigated. • Mutant population developed cross-resistance to ALS inhibitors. • The W574L mutation in the ALS2 protein results in reduced binding affinity for ALS inhibitors. • P450-mediated metabolic resistance might be involved in resistance to penoxsulam in mutant population. • Overexpression of mutant ALS2 in Arabidopsis thaliana showed resistance to ALS inhibitors. [ABSTRACT FROM AUTHOR]

Penoxsulam is an acetolactate synthase (ALS)-inhibiting herbicide usually applied by post-emergence foliar spraying (PFS) for the control of Echinochloa crus-galli and numerous annual weeds in paddy fields. Herbicides applied by foliar spraying can have negative impacts on the environment, ecosystems, and human health. In this study, the response of E. crus-galli and rice to the PFS and post-emergence water-dispersal (PWD) applications of penoxsulam, and the differences in the detoxification displayed by them between the two treatment methods were compared. The results showed that the PWD application of penoxsulam provides a similar control efficacy against E. crus-galli as PFS at the 1-, 3-, and 5-leaf stages. Meanwhile, the PWD application had a higher safety for the rice. After being treated with 30 g a.i. ha−1 penoxsulam, residues were not detected in the rice treated by the PWD application method, whereas, with the PFS treatment, there was 59.0 µg/kg penoxsulam remaining. With the PFS application, there were many more residues of penoxsulam in the E. crus-galli than with the PWD method; the amount of residues was 32-fold higher 12 h after treatment. The in vitro enzyme activity assays revealed that the activities of ALS, glutathione-S-transferase (GST), and cytochrome P450 monooxygenases (P450) were increased in the PWD treatments, and were 1.5-, 1.3-, and 2.3-fold higher than with PFS 72 h after treatment. The real-time quantitative PCR (qRT-PCR) revealed that the GST1 and P450 genes, CYP81A14, CYP81A12, CYP81A18, and CYP81A21 were upregulated with the PWD application versus PFS in the E. crus-galli. In summary, these results demonstrate that the herbicidal activity was not affected by the upregulation of target and metabolic enzyme activities with the PWD application of penoxsulam. This research could contribute to application strategies reducing the risk of rice injury and environmental impacts by using water-dispersal formulations of penoxsulam.

Diflufenican is a carotenoid biosynthesis inhibiting herbicide, the synergistic effect, and field efficacy of diflufenican mixed with acetolactate synthase inhibiting herbicide penoxsulam against weeds in rice were evaluated in greenhouse and field. The results showed that penoxsulam combined with diflufenican exhibited an additive effect for the control of Echinochloa crusgalli, Digitaria sanguinalis, Cyperus difformis and Eclipta prostrata. When the dose ratio of penoxsulam and diflufenican was (1- 2)﹕(5-10), the weed control efficacy was higher than penoxsulam or diflufenican applied alone. The results of field experiments showed that the penoxsulam + diflufenican 300 g/L SC was safe for transplanted rice, and had good efficacy against E. crusgalli, C. difformis, Ammannia arenarid, and Ludwigia prostrata by spraying treatment on stem and leaf of rice 8 days after transplanting, especially to the notorious weeds such as A. arenarid and L. prostrata. The ratios of weed density and the fresh weight reduction were 93.8%-95.8% and 94.1%-96.1% 35 days after treatment with the doses of the active ingredients as 112.5-135.0 g/hm2 . The mixtures had significantly higher control efficacy than the conventional herbicides bensulfuron methyl + acetochlor 22% WP and penoxsulam or diflufenican alone. The combination of penoxsulam and diflufenican was safe for rice and could expand the weed control spectrum with high efficacy, which could be used in transplanted rice fields for annual weed control. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City, Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium. [Methods] The resistance to penoxsulam and bispyribac-sodium was screened in 11 E. crusgalli populations collected from rice production areas in Changde, Yiyang and Yueyang Cities, Hunan Province, and the resistance level of population HU-2 to penoxsulam was determined. [Results] HU-1 to HU-6 and HU-8A, a total of seven populations showed high levels of resistance to penoxsulam and bispyribac-sodium. The resistance level of population HU-2 to penoxsulam was extremely high; population HU-7 showed low-level resistance to both drugs; HU-11 population showed low-level resistance to penoxsulam and was susceptible to bispyribac-sodium; and populations HU-8 and HU-9 were susceptible to penoxsulam and bispyri-bac-sodium. [Conclusions] This study provides a technical basis for the rational for E. crusgalli in paddy fields. [ABSTRACT FROM AUTHOR]

Solid-phase extraction (SPE) and salting-out-assisted liquid–liquid extraction (SALLE) method was optimized and validated for the extraction and quantification of anilofos, bispyribac sodium, butachlor, pendimethalin, pretilachlor and penoxsulam from environmental water, soil and rice samples using HPLC and LC–MS/MS. The limit of detection and limit of quantification ranged from 0.0026 to 0.03 and 0.008 to 0.09 μg mL−1 in different matrices using HPLC and LC–MS/MS. Under the optimal conditions, mean percent recoveries ranged from 81.6 ± 4.1 to 98.6 ± 3.5, 84.1 ± 3.5 to 99.4 ± 3.2 and 81.3 ± 4.2 to 94.6 ± 3.5 in water, soil and rice, respectively, using SPE while 84.9 ± 2.9 to 102.3 ± 2.3, 90.0 ± 4.1 to 103.2 ± 4.1 and 86.3 ± 2.7 to 94.6 ± 3.5 using SALLE. Acceptable recoveries (> 80%) and precision (< 10%) for studied herbicides in water, soil and rice samples were obtained using SPE and SALLE. Further, the greenness was evaluated using AGREE metrics and Analytical Eco-Scale. SPE and SALLE were found to be greener methods and were efficient for the determination of herbicides from water, soil and rice. However, SALLE is advantageous over SPE in terms of cost-effectiveness, simplicity and easy handling. SALLE was used for extraction and quantification of herbicide from environmental water, soil and rice samples. Herbicide concentrations in soil and water samples at 0 day varied from 0.083 ± 1.65 to 1.381 ± 1.41 µg g−1. The concentration of studied herbicides in soil, rice and water at harvest was below the permissible limit (< 0.01 µg g−1). [ABSTRACT FROM AUTHOR]

A research trial was conducted at Agronomy Farm (SKUAST-K, Wadura, Jammu & Kashmir), during kharif 2017 and 2018 to evaluate nutrient removal in rice under various rice establishment methods and weed control measures. The study comprised of two factors: rice establishment techniques {Transplanting (TPR); Direct seeding (DSR) and System of rice intensification (SRI)} as main plot treatments and weed control measures {Butachlor @ 1500 g a.i ha−1 (B); Penoxsulam @ 22.5 g a.i ha−1 (P); Pyrazosulfuron ethyl + Pretilachlor @ 15 and 600 g a.i ha−1 (PP); Bensulfuron methyl + Pretilachlor @ 60 and 600 g a.i ha−1 (BP); 2 Conoweeding/Hand Weeding (CW/HW); Weed free (WF) and weedy check (WC)} as sub-plot treatments meant to evaluate the best establishment method and weed management practice for rice. Over DSR and transplanted rice, the SRI technique yielded a significant increase in dry biomass accumulation (17.04 and 17.20 t ha−1) and grain (7.92 and 8.17 t ha−1) and straw (9.60 and 10.17 t ha−1) yields. Penoxsulam herbicide significantly showed higher grain and straw yield of 8.19 and 8.28 t ha−1 and 10.13 and 10.44 t ha−1, respectively, than other weed management measures by comparing the means using critical difference. TPR excelled in reducing dry weed biomass more than other established methods. All herbicides considerably reduced dry weed biomass, but Penoxsulam herbicide showed the greatest reduction in dry weed biomass and proved superior against complex weed flora. Weeds showed maximum contribution towards total Biomass under DSR, among rice establishment techniques. In contrast, among different weed control measures, it was maximum in weedy check treatment (Untreated Control) and minimum in penoxsulam treatment. SRI significantly excelled in crop (grain and straw) nutrient uptake compared to the DSR and TPR method, although different crop establishment techniques non-significantly influenced nutrient concentrations. Furthermore, penoxsulam treatment demonstrated higher crop (grain and straw) nutrient uptake among the various weed management measures. However, available soil nutrients were observed among establishment techniques, highest in DSR and lowest in SRI. Moreover, direct-seeded rice excelled SRI and transplanted rice in weed nutrient uptake, and among the different herbicidal treatments, penoxsulam recorded the lowest uptake in weeds. Nutrient budgeting demonstrated that DSR showed the maximum percentage of nutrient removal by weeds, and the minimum ratio was in TPR. In contrast, the lowest rate of nutrients removed via weeds were seen in penoxsulam application under various weed management measures. [ABSTRACT FROM AUTHOR]

Penoxsulam is a new acetolactate synthase inhibitor (ALS) herbicide developed by Dow AgroSciences. In order to explore the sensitivity of Echinochloa spp. to penoxsulam on rice field, whole-plant bioassay experiments were conducted to evaluate the resistance level of 70 field populations of Echinochloa spp. from main rice production in seven provinces of China. The results showed that 50.0% of the 70 populations had evolved high resistance, 47.1% of the populations was moderate resistance, and only 2.9% of the populations exhibited low resistance. None populations were sensitive to penoxsulam. More than 60% of the populations had evolved high resistance from Hubei, Anhui, Ningxia and Heilongjiang Province. The populations of high level resistance was more than 25% in other three province. More than 60% of the population with moderate level resistance were from Hunan, Jiangxi and Jiangsu Province, and the populations of 20.0%-40.0% were also with moderate level resistance in others 4 provinces. The 10.0% and 12.5% of population were with low level resistance in Hubei and Heilongjiang Province, while other 5 provinces had no low level resistant populations. This work investigated the evaluation and monitoring of the field resistance of populations of Echinochloa spp. to penoxsulam, which provided a theoretical basis for the scientific application of penoxsulam to control Echinochloa spp. in the main rice cultivation area. [ABSTRACT FROM AUTHOR]

The study reports the results of in vitro experiments of compatibility of a new broad-spectrum herbicide mixture, penoxsulam + cyhalofopbutyl with Azospirillum lipoferum, Azotobacter chroococcum, Fraturaia aurantia and Bacillus megatherium and bio-control agent Pseudomonas fluorescens by disc diffusion method and Trichoderma viride by poison food technique. Results revealed that biofertilizer organisms A.lipoferum, A.chroococcum, F.aurantia and B.megatherium and bio-control agent P.fluorescens did not produce any zone of inhibition around the filter paper disc impregnated with 230, 240, 250, 260, 270, 280 and 290 Sl concentration of herbicide corresponding to herbicide dose of 115,120, 125, 130,135, 140 and 145 g ha-1, indicating that penoxusulam + cyhalofopbutyl is highly compatible with these organisms. The radial colony diameter of T. viride was significantly influenced by different concentrations of penoxsulam + cyhalofopbutyl. With an increase in the concentration of penoxsulam + cyhalofopbutyl, a decrease in colony diameter was observed and the percentage growth inhibition was in the range of 51.85 to 74. 82, indicating that penoxsulam + cyhalofopbutyl is moderately toxic to T.viride. The in vitro results revealed the possibility of using penoxsulam + cyhalofopbutyl for weed control at recommended doses (125, 130 or 135 g ha-1) under bio intensive disease management programme involving P.fluorescens and nutrient management programme involving A.lipoferum / A.chroococcum / B.megaterium / F.aurantia, suggesting the environmental safety of the herbicide. [ABSTRACT FROM AUTHOR]

Penoxsulam is new triazolopyrimidine sulfonamide herbicides; it is used to control annual grass and weeds in rice but it disrupts internally growing weeds in rice and inhibits the acetolactate synthase which is commonly found in plants. Sulfonamides drugs may also implicate in any allergic reactions in the body. In agricultural field farmers deals with various herbicides. Skin is the vital path of enter into the body for vulnerability situations and due to large surface area lot of chemicals infilterate the skin can metabolize foreign compound. As Rat and Human both have similar body plans and organs, therefore rat is used as the best model for biological scanning. The present study was conducted to determine the effect of repeated exposure of Penoxsulam herbicide for 28 days by topical route on the physiology of Wistar rats. This study evaluates that there was no clinical signs, skin reactions (Draize method) was noticed and no significant changes was observed in Bodyweight, Haematology, Biochemistry and Histopathology in treated groups after compared with control group of animals. Therefore, Penoxsulam at 1000 mg/kg body weight did not showed any adverse effect on skin to treated rats during the experimentation period. [ABSTRACT FROM AUTHOR]

The potential toxicity of five selected herbicides i.e. bispyribac-sodium, penoxsulam, haloxyfop-p-ethyl, pinoxaden, and tralkoxydim, and a pyrethriod insecticide deltamethrin was determined on the early 4th instar larvae (after 24, 48 and 72-h exposure) and pupae (after 24 and 48-h exposure) of Culex pipiens L. in the laboratory. As a result, deltamethrin was count as the most toxic compound on the early 4th instar larvae and pupae of Cx. pipiens compared with all tested herbicides after exposure times. For the tested herbicides, pinoxaden was the most potent herbicide against both tested developmental stages followed by bispyribac-sodium and penoxsulam, which exhibited a moderate toxicity; while haloxyfop-p-ethyl and tralkoxydim were deemed to be the lowest toxic compounds among all tested pesticides after exposure times. In addition, the toxicity of all pesticides against larval and pupal stages of mosquito was increased gradually as exposure time increased especially after 72-h exposure for larvae and 48-h exposure for pupae. In conclusion, this is the first report on the side toxicity effects of haloxyfop-p-ethyl, tralkoxydim, penoxsulam and bispyribac-sodium on immature stages (larvae and pupae) of Cx. pipiens mosquitos in Egypt.

A safe use of herbicide in the environment can be assessed by it's adsorption – desorption behavior in soil. In the present work laboratory studies were performed to examine adsorption-desorption behavior of penoxsulam herbicide on six soils having widely different properties. Adsorption kinetics of penoxsulam was best accounted by pseudo-first order model. Among acidic soils, soil having the lowest pH (5.36) showed highest partition coefficient (kd) whereas, in case of alkaline soils, soil of relatively less alkaline pH (7.88) and higher silt and organic content had higher kd value. The kd of penoxulam showed a highly significant and negative correlation with soil pH (r = −0.987, significant at p ≤ 0.01). Adsorption-desorption data fitted well to Freundlich isotherm model. Percent desorption of penoxsulam showed a highly significant and positive correlation with soil pH (r = 0.973, significant at p ≤ 0.01). Step-wise multiple regression analysis revealed that kd, Freundlich adsorption-desorption isotherm constants and hysteresis of penoxulam in soils could be successfully predicted by soil properties. The fourier transformed infrared spectral comparisons showed that adsorption of penoxsulam on soil occurred through H-bonding of several polar moieties with soil constituents besides a likely complex reaction of triazole group with some transition metals present on soil exchange complex. [ABSTRACT FROM AUTHOR]

A research trial was conducted at Agronomy Farm (SKUAST-K, Wadura, Jammu & Kashmir), during kharif 2017 and 2018 to evaluate nutrient removal in rice under various rice establishment methods and weed control measures. The study comprised of two factors: rice establishment techniques {Transplanting (TPR); Direct seeding (DSR) and System of rice intensification (SRI)} as main plot treatments and weed control measures {Butachlor @ 1500 g a.i ha−1 (B); Penoxsulam @ 22.5 g a.i ha−1 (P); Pyrazosulfuron ethyl + Pretilachlor @ 15 and 600 g a.i ha−1 (PP); Bensulfuron methyl + Pretilachlor @ 60 and 600 g a.i ha−1 (BP); 2 Conoweeding/Hand Weeding (CW/HW); Weed free (WF) and weedy check (WC)} as sub-plot treatments meant to evaluate the best establishment method and weed management practice for rice. Over DSR and transplanted rice, the SRI technique yielded a significant increase in dry biomass accumulation (17.04 and 17.20 t ha−1) and grain (7.92 and 8.17 t ha−1) and straw (9.60 and 10.17 t ha−1) yields. Penoxsulam herbicide significantly showed higher grain and straw yield of 8.19 and 8.28 t ha−1 and 10.13 and 10.44 t ha−1, respectively, than other weed management measures by comparing the means using critical difference. TPR excelled in reducing dry weed biomass more than other established methods. All herbicides considerably reduced dry weed biomass, but Penoxsulam herbicide showed the greatest reduction in dry weed biomass and proved superior against complex weed flora. Weeds showed maximum contribution towards total Biomass under DSR, among rice establishment techniques. In contrast, among different weed control measures, it was maximum in weedy check treatment (Untreated Control) and minimum in penoxsulam treatment. SRI significantly excelled in crop (grain and straw) nutrient uptake compared to the DSR and TPR method, although different crop establishment techniques non-significantly influenced nutrient concentrations. Furthermore, penoxsulam treatment demonstrated higher crop (grain and straw) nutrient uptake among the various weed management measures. However, available soil nutrients were observed among establishment techniques, highest in DSR and lowest in SRI. Moreover, direct-seeded rice excelled SRI and transplanted rice in weed nutrient uptake, and among the different herbicidal treatments, penoxsulam recorded the lowest uptake in weeds. Nutrient budgeting demonstrated that DSR showed the maximum percentage of nutrient removal by weeds, and the minimum ratio was in TPR. In contrast, the lowest rate of nutrients removed via weeds were seen in penoxsulam application under various weed management measures.

Results of field experiments conducted during kharif 2016 and 2017 to study the effect of penoxsulam on weeds in transplanted rice are reported. The study comprised 7 treatments consisting of 3 doses of penoxsulam 2.5 per cent OD (20, 22.5 and 25 g ha-1), bispyribac-Na 10 per cent SC (20 g ha-1), pretilachlor 50 per cent EC (750 g ha-1), hand weeding (20 and 40 d after transplanting, DAT) and un-weeded control. Echinochloa crusgalli, Leptochloa chinensis, Caesulia axillaris and Cyperus iria were the major weeds. Application of herbicides reduced weed density and increased grain yield as compared to un-weeded control during both the growing seasons. Penoxsulam at 25 g ha-1 provided effective control of grasses and broad-leaved weeds and sedges with 88.24 and 87.05 per cent weed control efficiency at 45 and 60 DAT. The treatment recorded significantly more panicle length, though the grain yield was at par with penoxsulam @ 22.5 g ha-1 (7.14 and 7.12 t ha-1 and 7.23 and 7.37 t ha-1, during 2016 and 2017 respectively). Penoxsulam at 25 g ha-1 recorded 21.5 and 23.9 per cent increase in grain yield over unweeded control during 2016 and 2017 respectively. [ABSTRACT FROM AUTHOR]

Ludwigia decurrens Walter is a dicotyledonous plant belonging to the family Onagraceae. It is native to Central Eastern USA but has been spreading quickly and has naturalized in aquatic and riparian ecosystems (including rice paddy fields) in many countries; therefore, it is now considered an invasive noxious weed. L. decurrens is highly competitive with rice and causes a significant reduction in rice production. The objective of the present study was to evaluate the efficacy of the herbicide penoxsulam for the control of L. decurrens in rice fields. The seeds of L. decurrens were collected from four villages in Indonesia, and penoxsulam was applied to L. decurrens in seven dosages (0, 2.5, 5, 10, 20, 40, and 80 g a.i. ha−1) 3 weeks after seed sowing. The plant populations from Hegarmanah, Jatisari, and Joho showed complete mortality at the recommended dosage of penoxsulam (10 g a.i. ha−1). However, the plants from Demakan grew, flowered, and produced seeds 56 days after treatment with 40 g a.i. ha−1 of penoxsulam. The resistance index value of the population was 36.06. This is the first report of a penoxsulam-resistant weed from a dicotyledonous plant species and also the first report of a herbicide-resistant population of L. decurrens. The appearance of herbicide-resistant L. decurrens is a serious issue from both an environmental and an economic perspective, especially since protected forest and freshwater ecosystems are located at a short distance from the study area. Further research is needed to evaluate herbicide mixtures and/or the rotation of herbicide action sites. The identification of the penoxsulam-resistance mechanism in L. decurrens is also necessary to develop a herbicide resistance management strategy.

The title compound, C16H14F5N5O5S [systematic name: 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy-1,2,4-triazolo[1,5-c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide], is used as a herbicide. The asymmetric unit of this structure comprises two independent molecules, A and B. The dihedral angles between the ring planes of the triazolopyrimidine ring systems and the benzene rings are 68.84 (7)° for A and 68.05 (6)° for B. In the crystal, weak intermolecular π–π interactions, with centroid–centroid separations of 3.4456 (17) and 3.5289 (15) Å and C—F...π [3.5335 (17) Å and 107.92 (13)°] contacts link adjacent molecules into chains along [001]. C—H...O and C—H...F hydrogen bonds link type B molecules into chains parallel to (100). Additional C—H...F hydrogen bonds together with short F...F contacts further aggregate the structure into a three-dimensional network.