Response of stevia to herbicides applied post-transplant in the greenhouse

Abstract Greenhouse studies were conducted to determine the response of stevia to several herbicide modes of action applied 2 wk after transplanting (WAP). At 1 wk after treatment (WAT), aciflourfen, metribuzin, and carfentrazone injured stevia 34 to 39%. In contrast, S -metolachlor, linuron, halosufluron, ethalfluralin, pyroxasulfone, pendimethalin, and tryfloxysulfuron injured stevia <20%, 1 WAT. By 4 WAT, stevia injury was ≤ 19% regardless of treatment, except metribuzin and trifloxysulfuron with 84 and 69% injury, respectively. S -metolachlor, linuron, ethalfluralin, pendimethalin, and pyroxasulfone did not reduce aboveground biomass compared to the nontreated check, 4 WAT. Linuron, ethalfluralin, pendimethalin, and pyroxasulfone did not reduce belowground biomass. Linuron, pendimethalin, and ethalfluralin may provide new modes of action for POST-transplant weed management in stevia. However, further research is needed to evaluate the effect of these herbicides on stevia growth and quality in the field.