Interest in using foliar fungicides continues to increase. Foliar fungicides have always been considered an effective management tactic when disease pressure warrants the application (Boerboom et al., 2008). Recently, however, foliar fungicides are being marketed for things like Plant Health or Plant Performance. Therefore, it is critical to further our understanding regarding if and when a foliar fungicide is effective for corn production in Wisconsin. Estimates for 2008 indicate that the number of acres in Wisconsin that received a foliar fungicide increased over 2007, when approximately 10% of the acreage was sprayed (400,000- 500,000 acres). Across the U.S., management of corn diseases is a process that requires decisions at multiple hierarchies (Table 1), including decisions made both pre- and post-planting. In this hierarchy is the use of foliar fungicides. The same factors that are used for managing corn diseases can be applied to determine the relative efficacy of an application of a foliar fungicide. Hybrid susceptibility is the number one factor to consider, followed by production practices like continuous corn and no-tillage corn, and having a high risk for leaf diseases.
Soil Science Extension
University of Wisconsin Madison