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Scott J Mcelroy - One of the best experts on this subject based on the ideXlab platform.
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a novel mutation a212t in chloroplast protoporphyrinogen oxidase ppo1 confers resistance to ppo inhibitor Oxadiazon in eleusine indica
Pest Management Science, 2020Co-Authors: Bo Bi, Qiang Wang, Jeffrey J Coleman, Aimone Porri, John Peppers, Jinesh D Patel, Michael Betz, Jens Lerchl, Scott J McelroyAbstract:BACKGROUND: Protoporphyrinogen oxidase (PPO) with two isoforms, chloroplast-targeted (PPO1) and mitochondrial-targeted (PPO2), catalyzes a step in the biosynthesis of chlorophyll and heme. PPO1 and PPO2 are herbicide target sites of PPO-inhibiting herbicides. Target-site mutations conferring resistance to PPO inhibitors have all thus far been in PPO2. Oxadiazon is a unique PPO inhibitor utilized for preemergence Eleusine indica control. In this research, we evaluated the response of two previously confirmed Oxadiazon-resistant and susceptible E. indica biotypes to other PPO inhibitors and identified the resistance mechanism in two Oxadiazon-resistant E. indica biotypes. RESULTS: Two E. indica biotypes were resistant to Oxadiazon, but not to other structurally unrelated PPO inhibitors, such as lactofen, flumioxazin and sulfentrazone. A novel mutation A212T was identified in the chloroplast-targeted PPO1, conferring resistance to Oxadiazon in a heterologous expression system. Computational structural modeling provided a mechanistic explanation for reduced herbicide binding to the variant protein: the presence of a methyl group of threonine 212 changes the PPO1 active site and produces repulsive electrostatic interactions that repel Oxadiazon from the binding pocket. CONCLUSION: The novel A212T mutation in PPO1 conferring resistance specifically to PPO inhibitor Oxadiazon was characterized. This is the first evidence of the direct role of PPO1 in the PPO mode of action, and the first evidence of evolved resistance in PPO1. (c) 2019 Society of Chemical Industry.
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identification of goosegrass eleusine indica biotypes resistant to preemergence applied Oxadiazon
Weed Technology, 2017Co-Authors: Scott J Mcelroy, William B Head, Glenn WehtjeAbstract:Goosegrass biotypes from golf courses in Richmond, VA (CCV) and New Bern, NC (RB) historically treated with Oxadiazon were identified as resistant compared to susceptible standard (PBU) based on comparisons of Oxadiazon applied preemergence at increasing rates (0.03 to 2.24 kg ha-1). Oxadiazon at rates ≤ 2.24 kg ha-1 rate did not prevent emergence of suspected resistant CCV and RB seedlings. PBU emergence was completely prevented at 0.14 kg ha-1. Based on percent seedling emergence relative to non-treated and percent above-ground biomass reduction relative to nontreated, the Oxadiazon rate at which emergence would be reduced 50% (I50) or 90% (I90) ranged from 0.12 to 0.18 kg ha-1 or 10.83 to 85.57 kg ha-1, respectively for suspected resistant CCV and RB, compared to 0.03 to 0.4 kg ha-1 or 0.12 to 0.19 kg ha-1, respectively for susceptible standard PBU. Seedling emergence data predicted 7.9 and 3.0 times greater I90 values for CCV and RB, respectively compared to biomass data. All three biotypes were compl...
Bo Bi - One of the best experts on this subject based on the ideXlab platform.
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a novel mutation a212t in chloroplast protoporphyrinogen oxidase ppo1 confers resistance to ppo inhibitor Oxadiazon in eleusine indica
Pest Management Science, 2020Co-Authors: Bo Bi, Qiang Wang, Jeffrey J Coleman, Aimone Porri, John Peppers, Jinesh D Patel, Michael Betz, Jens Lerchl, Scott J McelroyAbstract:BACKGROUND: Protoporphyrinogen oxidase (PPO) with two isoforms, chloroplast-targeted (PPO1) and mitochondrial-targeted (PPO2), catalyzes a step in the biosynthesis of chlorophyll and heme. PPO1 and PPO2 are herbicide target sites of PPO-inhibiting herbicides. Target-site mutations conferring resistance to PPO inhibitors have all thus far been in PPO2. Oxadiazon is a unique PPO inhibitor utilized for preemergence Eleusine indica control. In this research, we evaluated the response of two previously confirmed Oxadiazon-resistant and susceptible E. indica biotypes to other PPO inhibitors and identified the resistance mechanism in two Oxadiazon-resistant E. indica biotypes. RESULTS: Two E. indica biotypes were resistant to Oxadiazon, but not to other structurally unrelated PPO inhibitors, such as lactofen, flumioxazin and sulfentrazone. A novel mutation A212T was identified in the chloroplast-targeted PPO1, conferring resistance to Oxadiazon in a heterologous expression system. Computational structural modeling provided a mechanistic explanation for reduced herbicide binding to the variant protein: the presence of a methyl group of threonine 212 changes the PPO1 active site and produces repulsive electrostatic interactions that repel Oxadiazon from the binding pocket. CONCLUSION: The novel A212T mutation in PPO1 conferring resistance specifically to PPO inhibitor Oxadiazon was characterized. This is the first evidence of the direct role of PPO1 in the PPO mode of action, and the first evidence of evolved resistance in PPO1. (c) 2019 Society of Chemical Industry.
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A Novel Mutation A212T in Chloroplast Protoporphyrinogen Oxidase (PPO1) Confers Resistance to PPO Inhibitor Oxadiazon in Eleusine indica
Pest Management Science, 2019Co-Authors: Bo Bi, Qiang Wang, Jeffrey J Coleman, Aimone Porri, John Peppers, Jinesh D Patel, Michael Betz, Jens Lerchl, J. Scott McelroyAbstract:Protoporphyrinogen oxidase (PPO) with two isoforms, chloroplast-targeted (PPO1) and mitochondrial-targeted (PPO2), catalyzes a step in the biosynthesis of chlorophyll and heme. PPO1 and PPO2 are herbicide target sites of PPO-inhibiting herbicides. Target-site mutations conferring resistance to PPO inhibitors have all thus far been in PPO2. Oxadiazon is a unique PPO inhibitor utilized for preemergence Eleusine indica control. In this research, we evaluated the response of two previously confirmed Oxadiazon-resistant and susceptible E. indica biotypes to other PPO inhibitors and identified the resistance mechanism in two Oxadiazon-resistant E. indica biotypes. Two E. indica biotypes were resistant to Oxadiazon, but not to other structurally unrelated PPO inhibitors, such as lactofen, flumioxazin and sulfentrazone. A novel mutation A212T was identified in the chloroplast-targeted PPO1, conferring resistance to Oxadiazon in a heterologous expression system. Computational structural modeling provided a mechanistic explanation for reduced herbicide binding to the variant protein: the presence of a methyl group of threonine 212 changes the PPO1 active site and produces repulsive electrostatic interactions that repel Oxadiazon from the binding pocket. The novel A212T mutation in PPO1 conferring resistance specifically to PPO inhibitor Oxadiazon was characterized. This is the first evidence of the direct role of PPO1 in the PPO mode of action, and the first evidence of evolved resistance in PPO1. © 2019 Society of Chemical Industry. © 2019 Society of Chemical Industry.
Miriam Hiroko Inoue - One of the best experts on this subject based on the ideXlab platform.
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determination of Oxadiazon residues in the field treated soil with and without organic matter incorporated
Environmental Earth Sciences, 2016Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ana Beatriz Rocha De Jesus Passos, Miriam Hiroko Inoue, Antonio Alberto Silva, Daniel Valadao SilvaAbstract:The behavior of Oxadiazon (5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2 (3H)-one) in the soil may be influenced by organic material content. The objective of this study was to chromatographically determine soil Oxadiazon residue content as a function of organic material and soil depth. A randomized block design was used, with treatments arranged in a scheme comprising 2 × 4 × 8 + 1 sub-subdivided plots with four repetitions. Plots were comprised of soil with (8 t ha−1) and without organic material incorporated, together with a control (0 t ha−1 and 0 g ha−1 of Oxadiazon). Subplots were based on soil depth (0.00–0.05; 0.05–0.10; 0.10–0.15 and 0.15–0.20 m) and sub-subplots on soil collection time (0, 2, 4, 8, 16, 32, 64 and 128 days after application—DAA). Oxadiazon was applied at 1 kg ha−1. For residue determination, samples were quantified via high performance liquid chromatography (HPLC) using the solid–liquid extraction with low temperature partitioning (SLE-LTP) technique. In the superficial layer at 0.00–0.05 m, dissipation t1/2 of Oxadiazon took between 56 and 51 days in soil with and without organic material incorporated, respectively. Oxadiazon was found in the upper layer (0.00–0.10 m) of soil until 64 DAA and did not occur at any other depth, demonstrating low soil mobility potential. In soils containing incorporated organic material, higher concentrations of Oxadiazon were observed over different depths and evaluation periods.
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dinâmica de plantas daninhas apos aplicacao de Oxadiazon com simulacao de lâminas d agua e incorporacao de material orgânico
Revista Brasileira de Ciências Agrárias - Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Resumen pt: Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de ...
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Dinâmica de plantas daninhas após aplicação de Oxadiazon com simulação de lâminas d’água e incorporação de material orgânico
Revista Brasileira de Ciências Agrárias - Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Resumen pt: Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de ...
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dinâmica de plantas daninhas apos aplicacao de Oxadiazon com simulacao de lâminas d agua e incorporacao de material orgânico doi 10 5039 agraria v9i1a3679
Revista Brasileira de Ciências Agrárias (Agrária) Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de lâminas d’agua e incorporacao de material orgânico. Utilizou-se o delineamento em blocos casualizados com tratamentos dispostos em esquema fatorial 5 x 2, com 4 repeticoes. Os tratamentos foram constituidos pela combinacao da incorporacao (8 t ha-1) ou nao de material orgânico no solo e do momento de aplicacao de lâminas d’agua (0; 10 mm antes; 10 mm depois e sequencial de 10 mm antes e depois da aplicacao do Oxadiazon); alem da testemunha (0 mm e 0 g ha-1 de Oxadiazon). Foram obtidas a densidade relativa, a frequencia relativa, a abundância relativa, o indice de valor de importância (IVI) e o indice de similaridade (IS) da flora de plantas daninhas. Nao houve interacao significativa entre o material orgânico e as lâminas d’agua. A especie Cyperus rotundus apresentou maior IVI, independente do tratamento avaliado, seguidas da Urochloa decumbens , Galinsoga parviflora , Bidens pilosa e Melampodium perfoliatum . A maior similaridade (IS = 0,75) foi observada entre o tratamento que recebeu a aplicacao de 10 mm de lâmina d’agua antes associado com o de 10 mm depois de aplicacao do Oxadiazon.
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Leaching and residual effects of Oxadiazon as a function of the movement of water depth application and incorporation of soil organic matter
2014Co-Authors: Kassio Ferreira Mendes, Miriam Hiroko Inoue, Marcelo Rodrigues, Roque De Carvalho Dias, Cláudio Pagotto RonchiAbstract:Knowledge of soil and herbicide interactions is of fundamental importance for minimizing negative environmental consequences, especially to water resources, and to increase weedy plant control efficiency. The objective of this work was to evaluate the leaching and residual effects of Oxadiazon applied to pre-emergent plants by means of a bioassay as a function of the time of water depth application and soil organic matter. Using a randomized block design, the treatments were arranged in a scheme of subdivided parcels 4 × 2 × 4 + 1, with four repetitions. The experimental parcels were composed of the application time of the water depth (0; 10 mm before; 10 mm afterward; and 10 mm before and after the Oxadiazon application), beyond the control (0 mm and 0 g ha -1 of Oxadiazon). The subparcels that with or without soil organic matter incorporated (8 t ha -1 ) were evaluated, as were the subsubparcels of the soil depths (0.00 - 0.05, 0.05 - 0.10, 0.10 - 0.15 and 0.15 - 0.20 m). To determine Oxadiazon leaching (1,000 g ha -1 ), soil samples were collected 0, 30, 60 and 90 days after application (DAA) of Oxadiazon, and the residual effect was determined at 0, 15, 30, 45, 60, 75, 90 and 105 DAA. At 0 DAA, the leaching was greater with a sequential application of the water depth at 10/10 mm, reaching a depth of 0.15 - 0.20 m. The greatest half-life (t 1/2 ) of Oxadiazon was 54 days at the 0.00 - 0.05 m depth with the application 10 mm before and after the Oxadiazon application. Results showed that the application time of the water depth interfered with the leaching and residual effect of Oxadiazon in the soil, and may interfere with herbicide efficiency in controlling weedy plants and reaching the deepest soil depths. The incorporation of 8 t ha -1 of soil organic matter did not have any effect on these processes.
J. L. Vílchez - One of the best experts on this subject based on the ideXlab platform.
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determination of Oxadiazon residues by headspace solid phase microextraction and gas chromatography mass spectrometry
Journal of Chromatography A, 2002Co-Authors: A. Navalón, A. Prieto, L. Araujo, J. L. VílchezAbstract:Abstract A method for the determination of trace amounts of the herbicide Oxadiazon was developed using headspace solid-phase microextraction (HS-SPME), gas chromatography–mass spectrometry (GC–MS) and selected ion monitoring. It was applied to determine Oxadiazon in ground water, agricultural soil, must, wine and human urine samples. To determine Oxadiazon in liquid samples, a response surface methodology generated with a Doehlert design was applied to optimize the HS-SPME conditions using a 100 μm polydimethylsiloxane fibre. For the analysis of soil samples, they were mixed with water and the SPME fibre suspended in the headspace above the slurry. Ground water, human urine and must show linear concentration range of application of 0.5–50 ng ml−1 with detection limits ≤0.02 ng ml−1. HS-SPME–GC–MS analysis yielded good reproducibility (RSD values between 6.5 and 13.5%). The method validation was completed with spiked matrix samples. The developed analytical procedure is solvent free, cost effective and fast.
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Determination of Oxadiazon residues by headspace solid-phase microextraction and gas chromatography–mass spectrometry
Journal of Chromatography A, 2002Co-Authors: A. Navalón, A. Prieto, L. Araujo, J. L. VílchezAbstract:Abstract A method for the determination of trace amounts of the herbicide Oxadiazon was developed using headspace solid-phase microextraction (HS-SPME), gas chromatography–mass spectrometry (GC–MS) and selected ion monitoring. It was applied to determine Oxadiazon in ground water, agricultural soil, must, wine and human urine samples. To determine Oxadiazon in liquid samples, a response surface methodology generated with a Doehlert design was applied to optimize the HS-SPME conditions using a 100 μm polydimethylsiloxane fibre. For the analysis of soil samples, they were mixed with water and the SPME fibre suspended in the headspace above the slurry. Ground water, human urine and must show linear concentration range of application of 0.5–50 ng ml−1 with detection limits ≤0.02 ng ml−1. HS-SPME–GC–MS analysis yielded good reproducibility (RSD values between 6.5 and 13.5%). The method validation was completed with spiked matrix samples. The developed analytical procedure is solvent free, cost effective and fast.
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Determination of tebufenpyrad and Oxadiazon by solid-phase microextraction and gas chromatography-mass spectrometry
Chromatographia, 2001Co-Authors: A. Navalón, A. Prieto, L. Araujo, J. L. VílchezAbstract:A method for determination of trace amounts of the pesticides tebufenpyrad and Oxadiazon, previous solid-phase microextraction (SPME), was developed using gas chromatographymass spectrometry and selected ion monitoring (GC-MS; SIM). Both pesticides were extracted with a fused silica fiber coated with 100 μm polydimethylsiloxane. The effects of pH ionic strength, sample volume, extraction and desorption times as well as extraction temperature were studied. The linear concentration range of application was 0.5–250 ng mL^−1 for both compounds, with a detection limit of 0.06 ng mL^−1 for tebufenpyrad and 0.02 ng mL^−1 for Oxadiazon. SPME-GC-MS analysis yielded good reproducibility (RSD between 7.5–10.1%). It was used to check the eventual existence of tebufenpyrad and Oxadiazon above this limit in water and soil samples from Granada (Spain) as well as in human urine samples. The method validation was completed with spiked matrix samples. It can be applied as a monitoring tool for water, soil and urine in the investigation of environmental and occupational exposure to tebufenpyrad and Oxadiazon.
Kassio Ferreira Mendes - One of the best experts on this subject based on the ideXlab platform.
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determination of Oxadiazon residues in the field treated soil with and without organic matter incorporated
Environmental Earth Sciences, 2016Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ana Beatriz Rocha De Jesus Passos, Miriam Hiroko Inoue, Antonio Alberto Silva, Daniel Valadao SilvaAbstract:The behavior of Oxadiazon (5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2 (3H)-one) in the soil may be influenced by organic material content. The objective of this study was to chromatographically determine soil Oxadiazon residue content as a function of organic material and soil depth. A randomized block design was used, with treatments arranged in a scheme comprising 2 × 4 × 8 + 1 sub-subdivided plots with four repetitions. Plots were comprised of soil with (8 t ha−1) and without organic material incorporated, together with a control (0 t ha−1 and 0 g ha−1 of Oxadiazon). Subplots were based on soil depth (0.00–0.05; 0.05–0.10; 0.10–0.15 and 0.15–0.20 m) and sub-subplots on soil collection time (0, 2, 4, 8, 16, 32, 64 and 128 days after application—DAA). Oxadiazon was applied at 1 kg ha−1. For residue determination, samples were quantified via high performance liquid chromatography (HPLC) using the solid–liquid extraction with low temperature partitioning (SLE-LTP) technique. In the superficial layer at 0.00–0.05 m, dissipation t1/2 of Oxadiazon took between 56 and 51 days in soil with and without organic material incorporated, respectively. Oxadiazon was found in the upper layer (0.00–0.10 m) of soil until 64 DAA and did not occur at any other depth, demonstrating low soil mobility potential. In soils containing incorporated organic material, higher concentrations of Oxadiazon were observed over different depths and evaluation periods.
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dinâmica de plantas daninhas apos aplicacao de Oxadiazon com simulacao de lâminas d agua e incorporacao de material orgânico
Revista Brasileira de Ciências Agrárias - Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Resumen pt: Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de ...
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Dinâmica de plantas daninhas após aplicação de Oxadiazon com simulação de lâminas d’água e incorporação de material orgânico
Revista Brasileira de Ciências Agrárias - Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Resumen pt: Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de ...
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sorption of Oxadiazon in soils cultivated in the brazilian cerrado
Planta Daninha, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, A A Pereira, A R S Nunes, C E M Santos, Ana Caroline De Lourdes Pereira AssisAbstract:The objective of this study was to evaluate Oxadiazon sorption in different soils of the Brazilian Cerrado, highlighting the correlations of lethal doses of this herbicide capable of inhibiting 50% of the dry matter accumulation of the bio-indicator (LD50) among the chemical characteristics of the soil and its direct and indirect effects. The experiment was carried out in a greenhouse in a randomized block design and four repetitions. Each experimental unit consisted of a pot with increasing rates of Oxadiazon and oat (Avena sativa), as the bio-indicator species. For sorption evaluation, washed sand and 22 soils (substrates) from Cerrado Brazilian's Alliaceae cultivated areas were used. LD50 and sorption ratio (SR) = [(LD50soil - LD50sand)/LD50sand] to the substrates were determined. Pearson correlation analysis was performed between the chemical characteristics of the substrates and the LD50 of Oxadiazon. A path analysis was quantified, to deploy only the significant correlations estimated in direct and indirect effects of the characters on LD50, which is a basic variable. A more pronounced LD50 (528.09 g ha-1) for the Cerrado soil sample resulted in higher SR (> 53.00), while in the washed sand substrate, LD50 corresponded only to 9.74 g ha-1 of the Oxadiazon (available in soil). It was concluded that Oxadiazon sorption is influenced by the chemical characteristics of the soils, highlighting the correlation with pH (CaCl2), magnesium content, aluminum, organic matter, organic carbon, and aluminum saturation.
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dinâmica de plantas daninhas apos aplicacao de Oxadiazon com simulacao de lâminas d agua e incorporacao de material orgânico doi 10 5039 agraria v9i1a3679
Revista Brasileira de Ciências Agrárias (Agrária) Brazilian Journal of Agricultural Sciences, 2014Co-Authors: Kassio Ferreira Mendes, Marcelo Rodrigues Dos Reis, Ronaldo Matias Reis, Remon Ribeiro Da Silva, W L Almeida, Miriam Hiroko InoueAbstract:Objetivou-se, neste trabalho, determinar o efeito do Oxadiazon no comportamento da comunidade de plantas daninhas em diferentes momentos de aplicacao de lâminas d’agua e incorporacao de material orgânico. Utilizou-se o delineamento em blocos casualizados com tratamentos dispostos em esquema fatorial 5 x 2, com 4 repeticoes. Os tratamentos foram constituidos pela combinacao da incorporacao (8 t ha-1) ou nao de material orgânico no solo e do momento de aplicacao de lâminas d’agua (0; 10 mm antes; 10 mm depois e sequencial de 10 mm antes e depois da aplicacao do Oxadiazon); alem da testemunha (0 mm e 0 g ha-1 de Oxadiazon). Foram obtidas a densidade relativa, a frequencia relativa, a abundância relativa, o indice de valor de importância (IVI) e o indice de similaridade (IS) da flora de plantas daninhas. Nao houve interacao significativa entre o material orgânico e as lâminas d’agua. A especie Cyperus rotundus apresentou maior IVI, independente do tratamento avaliado, seguidas da Urochloa decumbens , Galinsoga parviflora , Bidens pilosa e Melampodium perfoliatum . A maior similaridade (IS = 0,75) foi observada entre o tratamento que recebeu a aplicacao de 10 mm de lâmina d’agua antes associado com o de 10 mm depois de aplicacao do Oxadiazon.
