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| Registros recuperados: 22 | |
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| RUCHEL,Q.; VARGAS,L.; AGOSTINETTO,D.; FERNANDO,J. A.; LÜDTKE,R.; BOBROWSKI,V. L.. |
| RESUMOO azevém é uma planta daninha de ciclo anual, encontrada em praticamente todas as lavouras de inverno, em pomares e vinhedos da região Sul do Brasil. A espécie é normalmente controlada pelo herbicida glyphosate, no entanto, o uso continuado desse produto selecionou biótipos resistentes. Diferenças na suscetibilidade do azevém a herbicidas têm sido atribuídas a características morfológicas, anatômicas e genéticas das plantas. Os objetivos deste trabalho foram realizar a caracterização morfoanatômica, adequar metodologia para a análise citológica de cromossomos e indicar corantes para testes de viabilidade polínica de biótipos de azevém suscetível e resistentes ao herbicida glyphosate. As sementes dos biótipos de azevém suspeitos de resistência... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anatomia; Cromossomos; Lolium multiflorum; Morfologia; Poaceae. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582015000300567 |
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| AGOSTINETTO,D.; TAROUCO,C.P.; LANGARO,A.C.; GOMES,J.; VARGAS,L.. |
| ABSTRACT The main limiting factors for the productive potential of wheat crops are related to the competition with weeds for resources such as water, light and nutrients. Nitrogen (N) is an important nutrient used to maintain crop productivity, as well as promoting the competitive ability of crops and therefore suppress the weed growth. In this context, the goal of this study was to evaluate the effects of wheat plants in competition with ryegrass under different levels of nitrogen fertilization. Treatments were arranged in a factorial design, where factor A consisted in nitrogen rates (0, 60, 120, 180 and 240 kg ha-1) and factor B consisted in ryegrass and wheat plants ratios, which were: 100/0 (pure stand of 64 wheat plants), 50/50 (32 wheat plants and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen; Replacement series; Triticum aestivum; Lolium multiflorum. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582017000100247 |
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| DURIGON,M.R.; MARIANI,F.; CECHIN,J.; CAMERA,A.S.; VARGAS,L.; CHAVARRIA,G.. |
| ABSTRACT: This work aimed to compare the competitive ability of canola hybrids susceptible (conventional) or resistant to triazine or imidazolinone group herbicides, with turnip. The experiments were conducted in greenhouse, in a completely randomized design, with four replicates. The hybrids Hyola 571CL (resistant to imidazolinone), Hyola 555TT (resistant to triazine), and Hyola 61 (conventional) were used. The treatments consisted of ratios (100:0; 75:25; 50:50; 25:75; 0:100%) of canola and turnip plants. The evaluation was performed 44 days after emergence, determining the leaf área (AF), dry matter of aerial part (MSPA), and stature (EST) of the plants. The competitiveness analysis was performed through diagrams and interpretation of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brassica napus L.; Raphanus sativus L.; Interference; Competitiveness. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100171 |
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| GALON,L.; AGAZZI,L. R.; VARGAS,L.; NONEMACHER,F.; BASSO,F. J. M.; PERIN,G. F.; FERNANDES,F. F.; FORTE,C. T.; ROCHA,A. A.; TREVISOL,R.; WINTER,F. L.. |
| ABSTRACTThe objective of the study was to assess the relative competitive ability of canola hybrids in the presence of turnip (Raphanus sativus) and ryegrass (Lolium multiflorum) in different ratios of plants in the mixture. The experiments were conducted in a greenhouse, in a completely randomized design with four replications. Treatments were arranged in ratios of canola against turnip or ryegrass: 100:0, 75:25, 50:50, 25:75 and 0:100. Competitive analysis of the species was accomplished by means of diagrams usually applied to replacement series and also by the relative competitiveness indices. Fifty days after the emergence of the species, measurements of leaf area and shoot dry mass were performed. There was a competition between canola hybrids and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brassica napus; Raphanus sp; Lolium multiflorum. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582015000300413 |
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| DURIGON,M.R.; CAMERA,A.S.; CECHIN,J.; VARGAS,L.; CHAVARRIA,G.. |
| ABSTRACT: Canola is an important rotation crop for the winter season and the use of atrazine-resistant hybrids can lead to an increase in yield. This work was aimed at evaluating the effect of atrazine on photochemical and biochemical processes of photosynthesis in triazine-resistant canola. The experiment was conducted in a greenhouse, with triazine-resistant hybrid Hyola® 555TT, in a randomized block design with three replications. The treatments consisted of application or no application of atrazine on canola plants. The plants were assessed at one, three, five, and eight days after application (DAA) for chlorophyll indexes, modulated chlorophyll a fluorescence and gas exchange. Chlorophyll indexes were higher in canola plants treated with atrazine.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brassica napus; Chlorophyll indexes; Gas exchange; Modulated fluorescence. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100284 |
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| MARIANI,F.; SENSEMAM,S.A.; VARGAS,L.; AGOSTINETO,D.; ÁVILA,L.A.; SANTOS,F.M.. |
| ABSTRACT: Ryegrass(Lolium multiflorum)is one of the most worrisome species with regard to herbicide resistance. This study aimed at characterizing the acetolactate synthase (ALS) enzyme activity of resistant biotypes (NC and AR) and susceptible biotypes to iodosulfuron-methyl-sodium (iodosulfuron). Different concentrations of pyruvate (1, 10, 20, 40, 60, 80 and 100 mM), of iodosulfuron (0 to 100 µM for the resistant biotypes and 0 to 0.5 µM for the susceptible biotype) and concentrations of valine, leucine and isoleucine (0, 0.001, 0.01, 0.1, 1, 10 and 100 mM) were used for the in vitro characterization. According to the results, the Michaelis constant (Km) values (pyruvate) for the assessed biotypes were similar. With iodosulfuron, resistant biotypes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acetolactate synthase (ALS); Lolium multiflorum; Amino acids; Sulfonylurea. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100201 |
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| SCHMITZ,M.F.; CECHIN,J.; HENCKES,J.R.; PIASECKI,C.; AGOSTINETTO,D.; VARGAS,L.. |
| ABSTRACT: The intergenotypic competition of tetraploid ryegrass with natural diploid population may be a tool to reduce the frequency of resistant individuals in an area. This study aimed to identify and compare the phenological development, fitness cost, and competitive ability between diploid and tetraploid ryegrass genotypes. Genotypes were grown in pots, and the morphological variables of genotype growth were assessed every 15 days up to 120 days after emergence to evaluate the fitness cost. Phenological development and seed yield components were measured in a single time together with the fitness cost. Competitive ability was determined in a replacement-series experiment with proportions of tetraploid and diploid ryegrass, in which the number of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lolium multiflorum; Competition; Diploid; Tetraploid; Integrated weed management. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100189 |
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| VARGAS,L.; SCHNEIDER,T.; AGOSTINETTO,D.; BIANCHI,M.A.. |
| ABSTRACT Ryegrass is a weed of annual cycle that is present in winter crops, in orchards and vineyards of the South region of Brazil. The species is normally controlled by the glyphosate herbicide, but the continuous use of this product caused the selection of resistant biotypes. The use of ACCase inhibitor herbicides is the main alternative for the control of this species, but it has not been satisfactory in some places, thus causing suspicion of resistance to this action mechanism. Thus, the objective of this paper was to evaluate the occurrence and geographic distribution of ryegrass biotypes that are resistant to the clethodim herbicide in the state of Rio Grande do Sul. For that, seeds of ryegrass plants that survived the application of clethodim were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lolium multiflorum; Resistance; Chemical control; Acetyl coenzyme A carboxylase. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000200365 |
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| PIASECKI,C.; MAZON,A.S.; MONGE,A.; CAVALCANTE,J.A.; AGOSTINETTO,D.; VARGAS,L.. |
| ABSTRACT: Glyphosate-resistant hairy fleabane [Conyza bonariensis (L.) Cronq.] is one of the most important weeds in the world. Among the factors that make this weed species widely distributed in the most diverse environments is the high seed production capacity and dispersal. Hairy fleabane plants not controlled by herbicide application regrowth and overcome crop canopy, use environmental resources, interfere with crops, and complete their life cycle by producing thousands of seeds and replenishing the seed bank. Management strategies that reduce production and viability of hairy fleabane seeds can be adopted within the integrated management to reduce the seed bank and prevent further infestations. In this way, experiments were carried out in a greenhouse... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza bonariensis; Resistance; Integrated weed management; Prevention; Soil seed bank. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100198 |
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| BENEMANN,D.P.; NOHATO,A.M.; VARGAS,L.; AVILA,L.A; AGOSTINETTO,D.. |
| ABSTRACT Real time reverse transcription polymerase chain reaction (RT-qPCR) is an important technique to analyze differences in gene expression due to its sensitivity, accuracy, and specificity. However, before analyzing the expression of the target gene, it is necessary to identify and evaluate the stability of candidate reference genes for the proper normalization. This study aimed at evaluating the stability of candidate reference genes in order to identify the most appropriate genes for the normalization of the transcription in rice and red rice in competition under different nitrogen levels, as well as to demonstrate the effectiveness of the reference gene selected for the expression of the cytosolic ascorbate peroxidase (OsAPX2). Eleven candidate... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Gene expression; Normalization. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582017000100215 |
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| LANGARO,A.C.; AGOSTINETTO,D.; OLIVEIRA,C.; FRANCO,J.J.; ZANDONÁ,R.R.; VARGAS,L.. |
| ABSTRACT: Chemical weed control and nitrogen fertilization are common practices in irrigated rice crops. Nitrogen is an essential element for growth and development of plants and may influence herbicide selectivity. In this study, herbicide selectivity was evaluated according to nitrogen application time in irrigated rice crops. The experiment was conducted in the field in a split-plot design with four replications. Treatments were arranged in a factorial scheme: factor A consisted of different nitrogen application times (without nitrogen, all nitrogen applied before flooding, half of the nitrogen rate applied before flooding and the other half after flooding, all nitrogen applied after flooding); factor B consisted of the application of the herbicides... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Nitrogen; Selectivity; Weeds. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100318 |
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| SILVA,D.R.O.; AGOSTINETTO,D.; VARGAS,L.. |
| ABSTRACT With the increase of glyphosate resistance evolution in hairy fleabane, the knowledge of genetic diversity is essential to assist in the weed management. The objective was to characterize the genetic diversity of glyphosate resistant Conyza species in Rio Grande do Sul. Hairy fleabane biotype seeds were collected in fields of glyphosate-resistant soybean, generating seedlings used for extracting DNA from the leaves to perform a genetic diversity analysis, using the RAPD technique. The DNA was used in polymerase chain reaction and DNA fragments were assessed for polymorphism bands in electrophoresis. Biotypes were identified as Conyza bonariensis and microcephala varieties. In molecular analysis, among 25 primers RAPD, eight were reproducible... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza bonariensis; Polymorphism; Glyphosate; PCR. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000300433 |
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| AISENBERG,G.R.; WESTENDORFF,N.R.; LANGARO,A.C.; VARGAS,L.; AGOSTINETTO,D.. |
| ABSTRACT: Horseweed control through application of 2.4-D in the winter season is an alternative to manage biotypes resistant to herbicides that belong to other mechanisms of action. The objectives of this study were to assess the physiological quality of wheat seeds and determine the rate of 2.4-D residue, as function of application stages and herbicide rates. The treatments were arranged in factorial scheme, with three application stages (flowering, soft dough and hard dough), and four 2.4-D rates (0; 504; 1,008 and 2,015 g a.i. ha-1). The application of 2.4-D in the wheat crop changed physiological seed quality by increased the rate and total percentage of germination. The application of 2.4-D resulted in herbicide accumulation in seeds, especially when... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum; Weeds; Germination; Dry matter. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100205 |
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| VARGAS,L.; HENCKES,J.R.; GAVA,F.; AGOSTINETTO,D.; CARVALHO,I.R.; RAMOS,R.; RODRIGUES,R.. |
| ABSTRACT: Resistance to herbicides is one of the main factors responsible for weed control failures. Once uncontrolled and stressed, resistant weeds demand a new application of herbicides from different modes of action, which results in higher monetary costs and environmental impact. Knowledge of weed sensitivity levels to herbicides before making decisions for their management in the field is paramount to increasing the efficiency of integrated weed management. Thus, methods that allow the rapid determination of sensitivity levels can help to the correct recommendation before the application, and thus, favor the greater technical, economic and environmental efficiency of weed management. The objective of this work was to validate a rapid method to detect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Integrated weed management; Resistance; Control; Efficiency. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100222 |
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| CECHIN,J.; VARGAS,L.; AGOSTINETTO,D.; ZIMMER,V.; PERTILE,M.; GARCIA,J.R.. |
| The repetitive use of iodosulfuron for the control of weeds in winter cereals in the south of Brazil has favored the emergence of resistant Raphanus sativus biotypes. The objective of this study was to evaluate: the response of Raphanus sativus biotypes susceptible and resistant to different dosages of iodosulfuron; the control of biotypes with alternative registered herbicides for the control of the species in crops of wheat, corn and soybean; and the existence of cross-resistance of the biotypes. Thus, four experiments were done in a greenhouse, with a completely randomized design and four replicates. The experimental units were composed of vases with a volumetric capacity of 0.75 L filled with substrate, containing a plant each. For the dose-response... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Raphanus sativus; Dose-response; Acetolactate synthase; Weed. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000100151 |
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| Registros recuperados: 22 | |
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