 I'm Nicole Haslip with Ag Headline News. I'm Brownfield. Tar spot prevention and detection are top of mind for many corn growers. University of Minnesota Extension's Angie Pelter says, When corn begins to tassel, that's really when we would target a fungicide application. Many farms in the upper Midwest are overwhelmed by astonishing amounts of water. Minnesota's Darren Johnson says a year's worth of rain has fallen in less than three weeks.