Confirmation of Multiple Resistant Chloris radiata Population, Harvested in Colombian Rice Fields

This paper reports the first C. radiata population with resistance to glyphosate and multiple acetolactate synthase (ALS) inhibitor, imazamox. Two populations, one putative resistant (R) susceptible (S), were used in studies. Dose–response experiments performed evaluate factor (RF). Shikimic acid accumulation, 5-enolpyruvylshikimate-3-phosphate (EPSPS) ALS enzyme activities studied together chemical integrated weed management (adjuvants alternative herbicides). The imazamox was confirmed based on dry weight reduction, visual evaluation survival. results of dose–response curve assays showed for R intermedium RF (5.1 9.7 amount herbicide needed reduce by 50% GR50 lethal dose LD50, respectively) high (34.9 37.4, respectively). low shikimic accumulation resistance. concentration which inhibited EPSPS (I50) approximately 20 times higher than S population, while I50 plants 89 greater plants. In management, foliar retention effectivity that use adjuvants improves imazamox, reduction weeds. herbicides study acetyl-CoA carboxylase (ACCase) inhibitors, paraquat glufosinate, had better control this species. However, poor observed bispyribac-sodium, metsulfuron-methyl quinclorac, indicating possible cross-resistance ALS-inhibitors also auxinic (quinclorac). Nevertheless are required confirm assumption.