Dont bother if any stem has elongated. Liberty is a little bit more forgiving on the reproductive organs than roundup ( with roundup if you see any buds=no go)
If you have buds but no stem elongation ok... If you do youre just hurting it. Better off to let it be a bit dirty. Hope the canola cabbages out and chokes out some of the weeds. Then take it off dirty and get .5% more dockage. Big deal. Rather have a 50 crop at 2% than a 45 @ 1% dockage