Updated: Kochia control in corn
* Verdict, formerly known as Integrity, which is a Kixor-powered combination of Sharpen and Outlook herbicides.
* Prequel, which is a premix of Resolve and Balance.
Balance Flexx, Corvus, and Prequel cannot be applied on coarse-textured soils with shallow (25 feet or less) groundwater. Always consult the labels for details.
If kochia becomes a problem after the corn has emerged, there are several postemergence herbicide options. In Roundup Ready corn, glyphosate should be used even though resistant populations of kochia may be present. It is also a good idea to add one or more herbicides with a different mode of action to the glyphosate. This will not only help control any glyphosate-resistant populations present, but will also help prevent the development of glyphosate-resistant populations of kochia where such populations do not yet exist.
Possible glyphosate tankmix partners would include Status, Impact, Callisto, Laudis, Starane, Starane NXT, or Starane Ultra. If an HPPD-containing herbicide was used in the preemergence application (Lexar, Lumax, Corvus, or Balance Flexx), it would be a good idea not to use this mode of action in the postemergence treatment to help reduce the chances of resistant weeds developing. Another option in Roundup Ready corn is Halex GT plus atrazine. Halex GT is a premix consisting of a high rate of glyphosate, Dual II Magnum, and Callisto. Atrazine should be added to this product to get the best season-long control of kochia. With Impact, Callisto, Capreno, and Laudis, producers should include a half-pound of atrazine. (Note: The herbicide Impact has been marketed by AMVAC through an exclusive licensing agreement with BASF, which owns the active ingredient, topramezone. That licensing agreement is no longer exclusive with AMVAC. Starting in 2012, BASF will also begin marketing topramezone under the tradename Armezon. Both Impact and Armezon will be 2.8 lb/gal topramezone.)
In conventional corn, any of those postemergence herbicides mentioned above as tankmix partners with glyphosate can also be used alone, without the glyphosate tankmix partner. Halex GT cannot be used on conventional corn since it contains glyphosate.
Ignite can also be used as a postemergence treatment if the corn is Liberty Link. Ignite alone will not control kochia, however. For kochia control, Ignite should be tankmixed with Status or other more effective postemergence products. Ignite herbicides are soon to be renamed Liberty to better associate their use with Liberty Link crops. Existing stocks of Ignite products in the marketplace can still be used according to label directions.