Camix and Lumax Labeled on Sweet Corn

Chris Boerboom, Ext. Weed Scientist

April 6, 2006

Camix and Lumax have been labeled for use on processing and fresh market sweet corn.  Camix is a premixture of the ingredients in Callisto (mesotrione) and Dual II Magnum (s-metolachlor).  Lumax is a similar premixture, but includes atrazine in addition to the ingredients in Camix.  The atrazine concentration in Lumax is relatively low so that the atrazine rate limits for Wisconsin are not exceeded.  Because the Camix formulation lacks atrazine, it can be used in atrazine prohibition areas.  Camix can be tank mixed with Princep in atrazine prohibition areas if additional broadleaf control is needed.

Both Camix and Lumax can be applied as a preplant surface treatment up to 14 days before planting sweet corn or preemergence after planting sweet corn.  Do not apply either product postemergence to sweet corn.

Specifically, Camix is labeled at 2.0 qt/a on soil with less than 3% organic matter and at 2.4 qt/a on soil with greater than 3% organic matter.  Lumax is labeled at 2.5 and 3.0 qt/a on soils with less than and greater than 3% organic matter, respectively.                                                                                         

These premixtures will control a broad range of annual grass and broadleaf weeds.  For annual grasses, both products will provide good or excellent control of foxtails, crabgrass, barnyardgrass, and fall panicum.  Wild proso millet and sandbur may be controlled or suppressed initially, but some will likely escape control by midseason. Quackgrass will not be controlled.  Both products will also control many broadleaf weeds including lambsquarters, pigweeds, waterhemp, nightshades, and velvetleaf.  Lumax often controls common ragweed adequately, but Camix may be less consistent.  Both products are generally better on common ragweed than giant ragweed (both common and giant ragweed are labeled as being partially controlled).  Lumax controls wild buckwheat, but it generally escapes control with Camix.

We have not seen any injury from preemergence applications of the mesotrione ingredient in these products on the sweet corn hybrids that we have tested. However, the specific precautions for both products should still be followed.  Do not apply either product postemergence because the sweet corn may be injured.  Do not apply either product if wind speeds exceed 10 mph. 

The rotational restrictions may limit the use of Camix and Lumax in some crop rotations (see table). For later sweet corn plantings, both labels warn that applications after June 1 may injury rotational crops other than corn or sorghum.