I'm not familiar with Impact or Python.  Are these post herbicides?  Any residual activity (that is what I am needing)?

Teaweed is kind of like nightshade.  It's one of those weeds that for a long time has never caused any problems.  But in these 2 fields in tis rotation (seed corn, wheat/double crop soybeans) it has just gotten worse and worse.

And the fact it is seed production limits my options.  We have one field with a Liberty Link male and a Roundup Ready female.  If I were really good with a sprayer ...