|
|
|
| Registros recuperados: 35 | |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| SCHMITZ,M.F.; ZANDONÁ,R.R.; VARGAS,A.A.M.; GARCIA,J.R.; TUNES,L.V.M.; AGOSTINETTO,D.. |
| ABSTRACT: The commercialization of ryegrass seeds with the presence of resistant biotypes is a serious issue that increses the dispersion of resistance to new areas without this problem. Therefore, this study aimed to develop a quick test to detect susceptible and resistant seeds to the glyphosate herbicide in order to identify contaminated seed lots with glyphosate resistance. Three experiments were carried out, one in greenhouse and the other two in the seed laboratory. First, the resistance factor (RF) was determined by a dose-response curve experiment in biotypes suspected to be resistant and susceptible to glyphosate. Then, the germination test was conducted with the selected biotypes under increasing glyphosate rates (0, 3.5, 6.9, 13.9, 27.8, 55.5,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lolium multiflorum; Germination; Herbicide; Methodology. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100243 |
| |
|
|
| 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 |
| |
|
|
| CARATTI,F.C.; LAMEGO,F.P.; SILVA,J.D.G.; GARCIA,J.R.; AGOSTINETTO,D.. |
| ABSTRACT Plants compete for resources present below and above the soil surface. The objective of this work was to separate the individual effects of the competition for resources between soybean and corn as competitor plants. The experiment was conducted in a greenhouse, in 2014/2015. The treatments consisted of soybean cultivars (TEC 5718 and TEC 6029) in competition conditions with corn (no competition, competition for soil resources, competition for solar radiation and total competition). The variables evaluated were plant height at 7, 14, 21, 28, 35 and 42 days after emergence (DAE), stem/culm diameter, leaf area, shoot dry mass, root dry mass and the chlorophyll index, at 42 (DAE). The competition for soil resources between soybean and corn is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Zea mays; Water; Competitiveness; Solar radiation; Competitor plant. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000400657 |
| |
|
| |
|
|
| VARGAS,A.A.M.; AGOSTINETTO,D.; ZANDONÁ,R.R.; FRAGA,D.S.; AVILA NETO,R.C.. |
| ABSTRACT: Horseweed (Conyza spp.) is considered as one of the major weeds occurring in the agricultural areas of South America, especially in Brazil. This species stands out from the other weeds due to characteristics such as large seed production, continued seed production, dispersion over long distances and resistance to 5-enolpyruvoylshikimate 3-phosphate (EPSP) and acetolactate synthase (ALS) inhibiting herbicides, features that increase their management. Therefore, this study aimed at determining the physiological quality and longevity of horseweed seeds over 12 months. The experiment was established under field conditions, using a randomized block design with four replications. Fifty horseweed seeds were distributed into 50 g of dry soil, placed in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza spp.; Survival; Dormancy; Germination; Viability. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100249 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| MARCHEZAN,M.G.; AVILA,L.A.; AGOSTINETTO,D.; SCHAEDLER,C.E.; LANGARO,A.C.; OLIVEIRA,C.; ZIMMER,M.; SCHREIBER,F.. |
| ABSTRACT Herbicide selectivity in paddy rice varies in several aspects, among which are the environmental conditions. The aim of the study was to evaluate the effect of herbicide application and total plant submersion on morphological and biochemical changes in paddy rice. Total chlorophyll and carotenoids, catalase activity, ascorbate peroxidase and superoxide dismutase, total phenolic content, lipid peroxidation and hydrogen peroxide levels were assessed. Leaf samples were collected 24 hours and 7 days after the application of water regimes. The results observed in the first experiment show that cultivars Puitá INTA CL, IRGA 417 and IRGA 422 CL are more tolerant to total submersion. The most sensitive cultivars are IRGA 424, BRS Querência, EPAGRI 108 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oxidative stress; Hypoxia; Oryza sativa; Herbicide selectivity. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582017000100201 |
| |
|
|
| TAVARES,L.C.; LEMES,E.S.; RUCHEL,Q.; WESTENDORFF,N.R.; AGOSTINETTO,D.. |
| ABSTRACT: Weed competition limits wheat yield by reducing the availability of essential resources for its growth and development. In this sense, this study aimed to estimate the economic threshold level (ETL) of wild radish (Raphanus raphanistrum) in competition with wheat cultivars. Treatments were arranged in a factorial scheme. The factor wheat cultivar consisted of early (BRS 328), medium (BRS 177), and late (BRS Umbu) cycles and the factor wild radish population ranged from 0 to 564 plants m-2 (10 populations) for the cultivar BRS 328, 0 to 472 plants m-2 for the cultivar BRS 177 (11 populations), and 0 to 724 plants m-2 for the cultivar BRS Umbu (10 populations). The early-cycle BRS 328 presented a higher competitive ability when compared to the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum L.; Raphanus raphanistrum; Cultivars; Populations. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100204 |
| |
|
|
| OLIVEIRA,C.; AGOSTINETTO,D.; LANGARO,A.C.; GARCIA,J.R.; LAMEGO,F.P.. |
| ABSTRACT: The global temperature to rise 0.3 to 4.8 oC to century. Supra-optimal temperatures can affect plants at different organizational levels, causing morphological, physiological, biochemical and gene expression alterations. Rice, weedy rice, and barnyardgrass may to response differently when subjected to supra-optimal temperatures. Thus, the aimed at determining the physiological response and expression of the genes APX2, HSP24.15 e HSP71.10 in rice, weedy rice, and barnyardgrass when in to supra-optimal temperatures. A greenhouse experiment was conducted in randomized complete desing with four repetitions, with a factorial combination of temperature x plantas, where: factor A consisted of two temperatures (25 oC and 40 oC); and factor B of three... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Echinochloa spp.; Photosynthesis; Oxidative stress; Gene expression. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100239 |
| |
|
|
| 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 |
| |
|
|
| KASPARY,T.E.; LAMEGO,F.P.; LANGARO,A.C.; RUCHEL,Q.; AGOSTINETTO,D.. |
| ABSTRACT The resistance of weeds to herbicides is a consequence of one or more mechanisms in the plant, responsible for not allowing the herbicide to act properly at the active site. The objective of this study was to investigate the mechanism(s) of resistance to glyphosate in Conyza bonariensis. An experiment was conducted in November and December, 2012 and repeated in February and March, 2013 using a factorial arrangement of the treatments, where the factor A corresponded to biotypes of hairy fleabane, susceptible (S) and resistant (R); the factor B to seven rates of glyphosate from 0 to 11,520 g e.a. ha-1, and factor C were simulated environmental conditions of winter (12/8 oC day/night of temperature and 10/14 h of photoperiod) and summer (28/20 oC... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza bonariensis; Temperature; Photoperiod; EPSPs. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000300555 |
| |
|
| |
|
|
| LANGARO,A.C.; AGOSTINETTO,D.; OLIVEIRA,C.; SILVA,J.D.G.; BRUNO,M.S.. |
| ABSTRACT The application of herbicides, even if selective, can cause biochemical and physiological changes, resulting in oxidative stress. This stress comes from the accumulation of reactive oxygen species produced due to exposure to the herbicide. However, plants have developed defense strategies, which can be enzymatic or non-enzymatic. The objective of this study was to evaluate the morphological and metabolic changes such as photosynthetic parameters, oxidative damage and antioxidant enzyme activity of rice plants after applying herbicides. For this, a study was conducted in a greenhouse and laboratory and the treatments consisted of application of imazapic + imazapyr, quinclorac, bentazon, cyhalofop-butyl, penoxsulan, bispyribac-sodium and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Oxidative stress; Lipid peroxidation; Selectivity. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000200277 |
| |
|
| |
| Registros recuperados: 35 | |
|
|
|
