Summary Of Corn Fungicide Results From On-Farm Trials In Iowa In 2011

LEXINGTON, KY.

    Colleagues at Iowa State University (Drs. Daren Mueller and Alison Robertson) recently shared results of 23 on-farm fungicide trials, comparing different fungicides and timings. Most of these trials were conducted in low-disease conditions. (For the full report, go to:

 http://www.extension.iastate.edu/NR/rdonlyres/88CDD37F-E5D6-4CBA-B207-CA6B677942C8/164380/ISUFARMFinal.pdf.)

   I have summarized their timing work in Table 1. You can see that these studies show no advantage to applying fungicide early, and provided a modest positive response in about 40 percent of fields sprayed under mostly low disease conditions. These findings are consistent with the results of small-plot research conducted by other universities.

   Bottom line: On-farm studies in Iowa in 2011 showed no benefit to applying fungicide early in the season. A significant benefit was sometimes found when applied near R1. This is consistent with results of small-plot research. Δ

   DR. PAUL VINCELLI: Extension Plant Pathologist, University of Kentucky