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| Albrecht, Alfredo Junior Paiola; Pereira, Vinicius Gabriel Caneppele; Souza, Cristian Natalino Zanfrilli de; Zobiole, Luiz Henrique Saes; Albrecht, Leandro Paiola; Adegas, Fernando Storniolo. |
| Fleabane (Conyza spp.) is an important weed in grain production systems and is currently one of the most problematic weeds in Brazil. An important factor related to weeds such as fleabane is the characteristic of herbicide-resistant biotypes developed under selection pressure, with multiple resistance previously detected for Conyza spp. Thus, the aim of this study was to demonstrate the multiple resistance of Conyza sumatrensis to the herbicides paraquat, glyphosate, and chlorimuron. From the F2 seeds of biotypes with suspected resistance to paraquat, glyphosate, and chlorimuron, dose-response greenhouse experiments were conducted for the three herbicides. Herbicides were applied when the plants had 6-8 leaves that were at a height of 8 cm. At the end of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza spp.; Dose-response; Paraquat; Glyphosate; Chlorimuron. Conyza spp.; Dose-response; Paraquat; Glyphosate; Chlorimuron.. |
| Ano: 2020 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/42485 |
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| Trezzi,M.M.; Balbinot Jr.,A.A.; Benin,G.; Debastiani,F.; Patel,F.; Miotto Jr.,E.. |
| The existence of large areas infested with populations of Conyza spp. resistant to glyphosate in Brazil demands appropriate and integrated management strategies. This experiment aimed to identify soybean cultivars with greater competitive ability with horseweed plants and to determine plant characteristics associated with this ability. The experiment was arranged in a randomized complete block design with split plots. Seven soybean cultivars (CD 225 RR, BRS 232, CD 226 RR, NK 7054 RR, BMX Apollo RR, BRS 245 RR and BRS 255 RR) were allocated in the plots, and two interference situations (absence and 13.3 plants of Conyza m-2, transplanted seven days before soybean planting) in the subplots. The average yield loss due to competition with horseweed was 25%.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza spp.; Interference; Competition; Grain yield. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000300006 |
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| ROCHA,F.C.; OLIVEIRA NETO,A.M.; BOTTEGA,E.L.; GUERRA,N.; ROCHA,R.P.; VILAR,C.C.. |
| The aim of this study was to identify and map the weed population in a no-tillage area. Geostatistical techniques were used in the mapping in order to assess this information as a tool for the localized application of herbicides. The area of study is 58.08 hectares wide and was sampled in a fixed square grid (which point spaced 50 m, 232 points) using a GPS receiver. In each point the weeds species and population were analyzed in a square with a 0.25 m2 fixed area. The species Ipomoea grandifolia, Gnaphalium spicatum, Richardia spp. and Emilia sonchifolia have presented no spatial dependence. However, the species Conyza spp., C. echinatus and E. indica have shown a spatial correlation. Among the models tested, the spherical model has shown had a better fit... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conyza spp.; Geostatistics; Foci; No-tillage farming. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582015000100157 |
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| 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 |
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| Correia,Núbia Maria. |
| Abstract Background: Fleabane plants (Conyza spp.) resistant to glyphosate herbicide are found infesting areas in the Central-West and Southeast regions of Brazil, but its management is not a concerning problem for summer crops in these regions as in the South region of Brazil. Objective: To evaluate the management of adult fleabane plants at the summer soybean crop and off-season (autumn-winter), monitoring new emergences to assess the dynamics of plants from November 2018 to March 2020, and the residual effect of herbicides applied at the end of the rainy season in the Cerrado biome, in Brasília, DF, Brazil. Methods: Four field experiments were developed from November 06, 2018 to April 02, 2020; all under randomized block design, with four... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Conyza spp.; Residual herbicide; Weed control; Soybean. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100340 |
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| Bottega,Eduardo L.; Pegoraro,Camilo; Guerra,Naiara; Oliveira Neto,Antonio M. de; Queiroz,Daniel M. de. |
| ABSTRACT Brazil is one of the largest grain producers in the world, due to its extensive arable land and favorable climate for the cultivation of any species. The production could be higher, but problems such as competition between crops and weeds reduces crop yields. This study aimed to analyze the spatial distribution of weeds, especially milkweed (Sonchus oleraceus), horse weed (Conyza spp.) and ‘maria-mole’ (Senecio brasiliensis) in an area under no-tillage system for two harvests. The work was carried out during the 2013/14 and 2014/15 crop years in an area of 22.5 ha, where soybean is grown in the summer and oat in the winter. The weeds were mapped using a sampling grid of 85 points. The number of plants present in 0.25 m2 was recorded at each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Precision agriculture; Spatial variability; Sonchus oleraceus; Conyza spp.; Senecio brasiliensis. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001201107 |
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