Different Non-Target Site Mechanisms Endow Different Glyphosate Susceptibility in Avena Species from Spain

In recent decades, cereal agriculture across main producing areas in Spain has progressively adopted direct sowing, associated with an increased use of herbicides pre-sowing. Weedy species from genus Avena have been observed after the application glyphosate wheat. Here, fatua (two accessions), byzantina and sterilis subsp. sterilis, one accession each, were taxonomically characterized by a biometric study. Dose-response trials confirmed that A. evolved to resistance, because it was four times more resistant (R) than others, ascribed as susceptible (S). addition, based on LD50, had low susceptibility glyphosate, 604 458 g ae ha−1. Shikimic acid accumulation able discriminate between high (A. (S)), sterilis), (R)) populations. On other hand, study revealed (R), foliar uptake decreased movement glyphosate. metabolism showed less metabolite However, at 96 h application, convert 30% aminomethylphosphonic (AMPA) sarcosine. Enzyme basal activity I50 values predicted affinity herbicide target enzyme for all accessions, thus indicating target-site (TS) mechanism is probably not involved differences susceptibility. closing, non-target site (NTS) mechanisms could participate both R Spain.