Updated: Kochia control in corn
It should be noted that Balance Flexx and Corvus can be applied either preemergence or up through the 2-leaf stage of corn. If applied postemergence to corn, Balance Flexx and Corvus can be applied with atrazine only. No glyphosate or other adjuvants can be used. These products can do an excellent job of controlling kochia throughout the season if they are tankmixed with at least 1 lb/acre of atrazine. These products require moisture for soil activation, however they do have foliar activity.
Lumax and Lexar, which are best used as preemergence treatments, can also be applied early postemergence up to 12-inch corn when weeds are very small. Although waiting until this stage before application may work for controlling kochia, it is risky. Also, to get adequate grass control, these products must be applied preemergence to the grass.