^{I am looking for the answer also.
Seems like a residual is needed for this.
What to use?
Seems like it has to either be an ALS or a PPO.
Metribuzin is probably good for early to mid season cocklebur and waterhemp control.
Metribuzin is probably all gone by late season.
ALS’s are possibly better on cocklebur and not so good on waterhemp.
PPO’s are possibly better on waterhemp and not so good on cockleburs.}