Greater beggarticks (Bidens pilosa and Bidens subalternans) biotypes have been under selection pressure of ALS-inhibitors since early 90’s in Brazil. The objectives of this work were to investigate whether there are different cross-resistance patterns among ALS-inhibitors herbicides in Bidens spp. biotypes; to understand the geographic distribution of resistance patterns in grains producing regions in Brazil; and evaluate the possibility of multiple resistance to ALS-inhibitors, EPSPs inhibitor and photosystem II inhibitors. Dose-response experiments were carried out with imazethapyr, chlorimuron and diclosulam in three populations. Sensibility to others 34 populations both from Paraná State (PR) and from others Brazilian regions were also evaluated. The dose-response assay revealed cross-resistance with different patterns. One population was resistant to all three herbicides, the second population was tolerant to both imazethapyr and chlorimuron, but not to diclosulam, while a third population was resistant merely to imazethapyr. The results exhibited different cross-resistance patterns, since they can be found in other Bidens spp. populations. However, no relationship was observed between geographic areas where samples were collected and resistance patterns. Conclusively, the most frequent resistance pattern was R2 (resistance to imazethapyr, chlorimuron and diclosulam).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.