Applying soil-residual herbicides with non-residual, foliar-applied herbicides can help reduce additional weed emergence following application and, therefore, reduce the need for another application later. The “lateness” of this year’s soybean crop undoubtedly will decrease the number of acres where layered residuals are applied, but nonetheless keep in mind that labels for most soil-residual herbicides used in foliar applications include soybean growth stages or time intervals beyond which applications cannot be made. Additionally, these labels include time intervals for rotational crops, such as wheat. A partial listing of soil-residual herbicides sometimes applied post-emergence in soybean is presented in this table. Be sure to consult the label of any product used to determine maximum crop growth stage and rotational crop intervals.
Product | Maximum Soybean Growth Stage | Wheat Rotational Interval |
Anthem Maxx | Apply through third trifoliolate | 1 month at up to 3.25 oz. |
Dual Magnum | At least 90 days before harvest | 4.5 months |
FirstRate | Prior to R2 | 4 months |
Outlook | Fifth trifoliolate | 4 months |
Prefix | At least 90 days before harvest | 4.5 months |
Warrant | Before soybean reach R2 | 4 months |
Warrant Ultra | Before soybean reach R2 | 4 months |
Zidua SC | Third trifoliolate | 1 month at up to 3.25 oz. |