I have a field that had a few yellow weeds a few years ago, sprayed it along with the other weeds with roundup in corn.  Turns out it wasn't buttercup or mustard like I though it was.  It was RR canola, anyway it went to seed that year on me and now I have a little here and there in the field yet, coming volunteer.  What would give me a good knockdown and a residual to keep any from coming late season and going to seed again.  My spray dealer recommended Callisto 3oz. plus Flame water conditioner surfectant and I figure I'd throw a little Glyfosate in there to see if it does anything anymore.   Not saying what he recommended won't work, just wondering if there is something better or cheaper?  I have never seen a canola field within 40 miles of here.  I think it was in the broadcasted fertilizer.