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Registros recuperados: 136 | |
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SILVA,J.R.O.; MARQUES,J.N.R.; GODOY,C.V.C.; BATISTA,L.B.; SILVA,A.A.; RONCHI,C.P.. |
ABSTRACT: The hormesis effect of 2,4-D, applied at two stages of soybean development, on the physiological components of crop yield, was investigated. Soybean seeds of the cultivar ‘AG 3680 IPRO’ were sown in pots containing 7 L of a substrate and kept in a greenhouse. A randomized complete block design with four replicates was used. Eighteen treatments were tested, arranged in a split-plot scheme. The plots consisted of two stages of herbicide application (V4 and V6), and the split-plots were arranged by nine 2,4-D doses (0, 5, 10, 15, 20, 25, 30, 40, and 50 g ha-1). At the time of harvest, 100 days after sowing, significant interactions between crop development stages and 2,4-D doses were observed for the number of nodes in the main stem (NNMS) and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Auxin; Herbicide. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100154 |
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Roso,A.C.; Vidal,R.A.. |
Glyphosate is an herbicide that inhibits the enzyme 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPs) (EC 2.5.1.19). EPSPs is the sixth enzyme of the shikimate pathway, by which plants synthesize the aromatic amino acids phenylalanine, tyrosine, and tryptophan and many compounds used in secondary metabolism pathways. About fifteen years ago it was hypothesized that it was unlikely weeds would evolve resistance to this herbicide because of the limited degree of glyphosate metabolism observed in plants, the low resistance level attained to EPSPs gene overexpression, and because of the lower fitness in plants with an altered EPSPs enzyme. However, today 20 weed species have been described with glyphosate resistant biotypes that are found in all five... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Membrane carrier proteins; Herbicide; Weed resistance. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582010000500025 |
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Kogan,Marcelo; Metz,Alejandra; Ortega,Rodrigo. |
The objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series - Valdivia (Andisol), Clarillo (Inceptisol) and Chicureo (Vertisol) - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mg g¹ for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Dosage effects; Models. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2003000400010 |
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NAEEM,M.; CHEEMA,Z.A.; IHSAN,M.Z.; HUSSAIN,Y.; MAZARI,A.; ABBAS,H.T.. |
ABSTRACT: Use of synthetic herbicides to control weeds poses serious threats to sustainable agricultural production around the globe. The phytotoxic effect of different plant water extracts (i.e., sorghum, sunflower and mulberry) against weeds has been previously studied; however, their combined effects at different rates are yet to be explored. In this study, mixtures of allelopathic water extracts of sorghum + sunflower and sorghum + sunflower + mulberry were sprayed each at 12, 15, 18 and 21 L ha-1 at 40 and 55 days after sowing in wheat to control wild oats (Avena fatua), little seed canary grass (Phalaris minor), lamb’s quarters (Chenopodium album) and swine cress (Coronopus didymus). A synthetic herbicide Affinity 50 WP (Carfentrazone-ethyl 0.75% +... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Weed management; Allelopathy. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100299 |
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El-Rokiek,K.G; Eid,R.A. |
A Petri dish assay was carried out for screening different concentrations of aqueous extracts of fresh and dry leaves of Eucalyptus citriodora on germination and seedling growth of wild oat weed (Avena fatua). Seed germination, root and shoot length of wild oat exhibited different degrees of inhibition according to the concentration of the aqueous extract. Maximum inhibitions of germination percentage, root and shoot length were recorded when using 25% fresh leaf extract. Based on this preliminary work (Petri dish assay), studies were conducted under greenhouse conditions at the National Research Center, Egypt, in the two winter seasons of 2006/2007 and 2007/2008 to evaluate the effects of foliar and soil treatments of aqueous extracts of Eucalyptus... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aqueous extract; Herbicide; Phytotoxic; Total phenols; Tralkoxydim. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582009000500002 |
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SILVA,K.S.; FREITAS,F.C.L.; BRAGA,D.F.; DOMBROSKI,J.L.D.; SANTOS,A.F.B.. |
ABSTRACT Ametryn is one of the most widely used herbicides in the sugarcane culture. Little is known about the interactions between this herbicide and the attributes of soils in the sugarcane region of northeastern Brazil. This knowledge, before recommending herbicide, will minimize the negative effects on the environment, particularly on water resources, and will ensure weed control efficacy. In this work, ametryn leaching potential was estimated through bioassays and chromatography, in five soils from the sugarcane region in northeastern Brazil: Quartzarenic Neosol (Entisol); Red Argisol (Ultisol); Ferrihumiluvic Spodosol (Spodosols); Red-Yellow Acrisol (Oxisol) and Haplic Cambisol (Inceptisols). To achieve this, columns were prepared with samples of the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Liquid chromatography; Bioassay; Mobility. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000400839 |
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P. Ronchi,Cláudio. |
Abstract Background: Weed control in the pre-harvest of the coffee crop is essential to enable mechanized coffee harvesting. Objective: Testing the efficacy of pre-emergent herbicides, applied after brush shredder or desiccation operations, on the weed control during the coffee crop’s pre-harvest. Methods: Two separate trials were accomplished in commercial Coffea arabica crops in the Cerrado Mineiro Region. In the first one, oxyfluorfen and sulfentrazone were applied after either brush shredder or burndown operation; in the second, they were tested as a tank mixture with glyphosate. Results: In the first assay, the brush shredder use, associated to the rains that follow, stimulated a sharp weed infestation during the pre-harvest, which was not... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coffea arabica; Burndown; Herbicide; Integrated weed management. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100329 |
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WANG,Y.; YU,J.; ZHOU,B.; SAPKOTA,S.; WEI,F.; WANG,Z.. |
ABSTRACT: The effect of atrazine, mesotrione, and joint activity of atrazine plus mesotrione on pigment, lipid peroxidation, and antioxidant enzyme activity was studied. Atrazine and mesotrione treatments significantly reduced chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid concentrations, and protein content in bermudagrass (Cynodon dactylon L.) plants, whereas they significantly enhanced lipid peroxidation. The treatment of atrazine plus mesotrione caused greater phototoxic effect on bermudagrass than either herbicide alone, which was evident from the significantly decreased membrane stability noted as a function of the enhanced singlet oxygen and malondialdehyde (MDA) contents, as well as from the greater reduction in Chl a, Chl b, and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant; Carotenoids; Herbicide; Reactive oxygen species. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100337 |
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Gonçalves,Morgana S.; Sampaio,Silvio C.; Coelho,Silvia R. M.; Suszek,Floriano L.; Cordovil,Claudia M. D. S.. |
The effects of swine wastewater on atrazine dissipation and formation of bound residues in subtropical clay soil were investigated in this study. The experiment was carried out in laboratory, under room conditions, where samples of Rhodic Hapludox soil received 168.61 mg kg-1 of atrazine and were incubated for 60 days in the following treatments: T1 (sterilized soil + swine wastewater), T2 (sterilized soil + distilled water), T3 (Non sterilized soil + swine wastewater) and T4 (Non sterilized soil + distilled water). The extractable residues and bound residues of atrazine were extracted and analyzed by high performance liquid chromatography. The results showed no effect of swine wastewater on atrazine dissipation. However, the addition of swine wastewater... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Degradation; Sorption; Organic matter. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600017 |
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Souza,M.D. de; Basssoi,L.H.; Bacchi,O.O.S.; Reichardt,K.; Hermes,L.C.; Abakerli,R.B.; Pilotto,J.E.. |
Atrazine displacement was studied in a soil profile as a function of water movement and time after herbicide application, taking into account possible influence of preferential flow on leaching. The experiment consisted of two 7 x 7m plots of a dark red latosol (Kanduidalfic Eutrudox), located at Piracicaba, SP, Brazil (22º 43'S and 47º 25'W), 250km inside continent, at an altitude of 580m. One plot was previously treated with 1,000 kg/ha of lime, in order to increase base saturation to 88%, and 500kg/ha of gypsum. Each plot was instrumented with tensiometers, neutron probe access tubes and soil solution extractors, in order to monitor water and atrazine flows. Atrazine was applied at the high rate of 6 kg/ha of active principle. Results showed intensive... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atrazine; Leaching; Preferential flow; Adsorption; Herbicide; Tropical soil. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161997000300013 |
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PADILHA,M.; BARROSO,A.A.M.; CARVALHO,L.B.; COSTA,F.R.; BIANCO,S.. |
ABSTRACT The objective was to determine whether a change occurs in the critical period of weed interference prevention in narrow row corn with the use of atrazine and whether there is influence of the herbicide on crop yield components. The treatments consisted of periods without or with an initial weed control (0, 21, 35, 49, 63, 77, and 91 days after emergence), with or without application of atrazine in spikely post-emergence. The experiment was carried out in a 2 x 7 randomized blocks design (with and without weed control and seven periods with three replications). The use or not of atrazine was arranged in a split plot design. The most important weed species were Senecio brasiliensis, Urochloa plantaginea, Conyza bonariensis, Sida rhombifolia, and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Period of coexistence; Zea mays. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000400721 |
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Albrecht,A.J.P.; Albrecht,L.P.; Krenchinski,F.H.; Placido,H.F.; Lorenzetti,J.B.; Victoria Filho,R.; Barroso,A.A.M.. |
Recent studies indicate that glyphosate applied in post-emergence in RR soybean can eventually cause phytotoxic effects. However, there are many questions that need to be clarified in the scientific and technical contexts, involving the issue of RR soybeans regarding the use of glyphosate. This study has assessed the impact of the application of different doses and formulations of glyphosate in the reproductive period of RR soybean (R1 stage). For that purpose, an experiment in the field was conducted in two harvests (2011/12 and 2012/13), in which a 2 x 5 factorial design was used (formulations versus doses) totaling 10 treatments. In these two experiments the variables related to agronomic performance were: phytotoxicity (7, 14, 21 and 28 days after... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Herbicide; Transgenic crops; Phytotoxicity. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000400020 |
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Registros recuperados: 136 | |
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