Tough to give good answer without being there and knowing all variables, but mixing halo- with gly- is fine. One oz/A is plenty with that material. I used to use a bunch of it and only used 2/3 oz when I did with good results. Only reason I switched to a different material is price.
I'll say this, I treat 6-7k acres for nutsedge every year with the top three sulfos for that purpose, and I never seem to see major consistencies from any.
Nutsedge is a plague, no different than bermuda. Treat and Re-treat....over and over and over. Year after year after year.
Should you plant corn again next year, you may want to consider metolachlor(Dual) as part of your pre-emergent app. Can also be found in "Halex".
Thanks for the info! The corn was planted just because I wanted a crop of some kind there while I was trying to kill the nutsedge. I knew I wouldn't wipe it out with gly, but I thought I could set it back some. Wrong on that; I think it likes gly. I'm starting to understand why so many people hate yellow nutsedge so much.
So do you think that spraying the nutsedge areas with halo again just before the first frost would slow it up any next year? Or would it be a better use of the expensive chemical to just wait until it comes up next spring and hit it then?