Mark VanGessel, Extension Weed Specialist; email@example.com
Some of the earliest planted corn fields were sprayed with preemergence herbicide, but then had 7 to 10 days without rain to activate them. You need to check to those fields for emerging weeds and be prepared to spray earlier than you may have expected. Also, I have seen more yellow nutsedge this year than I have in the past few years. So be sure to identify those “grasses”, and be sure you know what grass species it is or whether it is nutsedge.