Cereal growers in Canada are being offered what's touted as the first-ever cereal burnoff herbicide with two separate modes of action, through two active ingredients.

Nufarm Agriculture has rolled out BlackHawk, a combination of 2,4-D ester 700 (Group 4) and carfentrazone (Group 14) for use in spring and durum wheat, barley, winter wheat and soybean crops.

Nufarm, which deals mainly in off-patent active ingredients, already markets canfentrazone under the name Aim, and in combination with glyphosate under the name CleanStart.

The company said it recommends BlackHawk for use by growers who are facing "hard-to-kill broadleaf weeds ahead of seeding" such as kochia (including Group 2- and glyphosate-resistant biotypes), volunteer canola and narrow-leaved hawk's beard.

Other "key weeds" on the label include Russian thistle, shepherd's purse, pigweed and flixweed, Nufarm's Calgary-based Canadian subsidiary said.

The product may also be tank-mixed to "heighten the performance of glyphosate" on dandelion, chickweed, cleavers and thistle, the company said.

"With so many glyphosate-resistant weeds out there, a straight glyphosate burndown is no longer as effective as it once was," Kim Bedard, Nufarm's marketing manager, said in a release Tuesday.