Scientific Research Publishing

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53030#.VLSCz8nQrzE Author(s)    Vijay K. Nandula 1* , Daniel H. Poston 2 , Clifford H. Koger 3 , Krishna N. Reddy 1 , K. Raja Reddy 4   Affiliation(s) 1 US Department of Agriculture-Agricultural Research Service (USDA-ARS), Crop Production Systems Research Unit, Stoneville, MS, USA . 2 Pioneer Hi-Bred International—Southern Business Unit, Huntsville, AL, USA . 3 Silent Shade Planting Company, Belzoni, MS, USA . 4 Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA . ABSTRACT Horseweed is traditionally considered a non-cropland weed. However, populations resistant to glyphosate have eventually become established in no-till agronomic cropping systems. Growth chamber and greenhouse experiments were conducted to compare selected biological and physiological parameters of glyphosate-resistant (GR) and -suscepti...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53010#.VK9E9cnQrzE Author(s)     Eduardo Puricelli 1* , Delma Faccini 1 , Marcelo Metzler 2 , Patricia Torres 1   Affiliation(s) 1 Facultad de Ciencias Agrarias and Consejo de Investigaciones, Universidad Nacional de Rosario, Rosario, Argentina . 2 INTA Paraná, Paraná, Argentina . ABSTRACT The aim of this study was to compare control of three stages biotypes (rosette, bolting, and repro- ductive stage) of Conyza bonariensis glyphosate susceptible biotype (S) and tolerant biotype (T) to glyphosate with glyphosate and mixtures of acetolactate synthase (ALS)-inhibiting. For glyphosate, the dose-response curves confirmed that injury of the biotype T relative to biotype S was signifi- cantly lower for both rosette and bolting stages. Resistance index (RI) for this herbicide was approximately 4 for both weed stages. At bolting, for both biotypes do...