Fierceâ„¢ Herbicide (active ingredients: flumioxazin + pyroxasulfone), the newest residual from Valent U.S.A. Corporation, has received US EPA registration in soybeans. Fierce, which received registration for corn earlier this year, is now available to soybean growers for the longest-lasting, broadest spectrum control of broadleaves and grasses, including species that are resistant to glyphosate and other chemistries.