It's not a pre em.
dont normally do maize except for one tight customer who wont pay another local contractor who charges more for lower acreages as my wheel settings dont meet row size and too wide so flatten one row but everyone round here seems to be using PDM this year pre em so got lots to doNever done pre ems unless huge grass weed pressure. Callisto + Millagro (Samson) post em isn't cheap but it nails everything & keeps it clean all season.