Callisto (mesotrione) is a new grass herbicide for use in sweet corn. It is labeled for both PRE and POST application. Excellent control of most broadleaves is obtained, with the exception of purslane and common ragweed. Its efficacy can be extended by tank mixing with Dual and/or AAtrex. In 2005 we applied alone, or in combination, Callisto, Dual II Magnum, and AAtrex 4L to Precious Gem sweet corn grown on a Clarion loam soil at the Horticulture Station, Gilbert, IA. The normal Callisto rate is 6 oz/acre PRE or no more than two 3 oz/acre applications as POST. Our highest POST application of Callisto was 12 oz/acre, 6 oz on June 22 and 6 oz on June 29, 2005. Injury to sweet corn, in form of bleaching of 10% of leaves, on July 7 was noted. Nonetheless, yields were high, averaging 1,931 dozen/acre.
Iowa State University
Taber, Henry G. and Lawson, Vincent, "Callisto Residual Evaluation Sweet Corn HerbicideTrial" (2007). Iowa State Research Farm Progress Reports. 852.