Abstract: Background: The advance of smooth pigweed and fleabane in soybean-ryegrass systems is associated with the evolution of weed resistance. Objective: Evaluate combinations of herbicides in burndown and pre-emergence for the control of smooth pigweed and fleabane in soybean, and the efficacy of herbicides in off-season management of smooth pigweed in ryegrass. Methods: Two field trials carried out in a complete randomized block design with four blocks. The first trial tested burndown (carfentrazone, carfentrazone+saflufenacil, carfentrazone+diquat, and diquat) and pre-emergent (PRE) […]