Invigor 2663 canola was seeded May 4 into 6-inch rows at 600,000 pls/A in a conventional tillage system. Individual plots were 10 x 30 ft and replicated three times. Treatments were applied preplant incorporated (PPI) on May 2, or postemergence on May 25 (0-2 lf), June 2 (3-4 lf), or June 8 (5-6 lf). The primary weeds were green foxtail (Grft), wild buckwheat (Wibw), common lambsquarters (Colq), and kochia (Kocz).

The study area had a low population of kochia, common lambsquarters, and wild buckwheat; and a moderate population of green foxtail. All Liberty treatments provided good to excellent control of green foxtail, wild buckwheat, common lambsquarters, and kochia at any rate or timing. None of the treatments caused visible crop injury. The treatments increased canola yield 250-550 lb/A over the untreated check. The canola crop was very competitive with the weeds, thus allowing even the reduced herbicide rates to be effective. The labeled use rate of Liberty is 28-34 fl oz/A. Higher weed densities and non-ideal spraying conditions may result in unacceptable weed control from reduced herbicide rates.