glyphosate
Rate 1 to 2 lb ae/A
Time When plants are at least 15 inches tall and growing rapidly.
Remarks Established stands are controlled best by the 2-lb rate applied after May 1 to undisturbed sites. Newly sprouted corms are controlled with the 1-lb rate, but less herbicide will move into attached unsprouted corms. A single application to dormant corms gives only limited long-term control; tillage and repeated applications will be required.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted