Jeff Coulter, Extension Corn Agronomist
In the past few years, the use of foliar fungicide on corn has gained considerable attention. In 2008, with generous support from the Minnesota Corn Growers Association and BASF, research was conducted in southern Minnesota at Lamberton and Waseca to determine how planting date impacted corn response to foliar fungicide. In these trials, corn followed soybean at 32,400 plants per acre, and the hybrid was DKC52-59. At both locations, there was little to no foliar disease at the time of fungicide application. The same was true at the early dent stage, regardless of whether fungicide was used. Nonetheless, yield was generally 3 to 4% (5 to 6 bushels per acre) higher when fungicide was applied, regardless of planting date or location (Figures 1 and 2). The exception was the early planting date at Waseca, where foliar fungicide resulted in a 6% yield increase (Figure 1). However, these numerical yield increases were not statistically significant, even at the 10% probability level. In other words, additional replication is needed in order to ensure that these differences are actually due to the treatments imposed, rather than random variability in soil productivity from one plot to the next.