Hot, humid weather, which now hits much of the South, spurs corn diseases. As corn reaches tasseling stage, is a fungicide needed to secure yield?

In a June 26 blog, Heather Young Kelly, University of Tennessee Extension plant pathologist, says fungicide application decisions should be based on several factors:

  • Hybrid (hybrids susceptible to gray leaf spot and other diseases are at higher risk for disease)
  • Cropping history (continuous corn is at higher risk for disease)
  • Disease pressure (diseases should be clearly identified to better choose a fungicide with good efficacy for that specific disease   
  • Weather conditions/irrigation (corn under irrigation or in years with moderate to high rainfall is likely to be at higher risk for disease)

Research data from University of Tennessee and other universities has continuously found these factors to strongly influence the magnitude and consistency of yield response to a foliar fungicide application in corn. The higher the risk for disease the greater the potential a corn field has from benefiting from a fungicide application. Lastly, fungicides applied at tasseling have shown in university research trials to have the most consistent results for controlling disease and protecting yield.

Read more of her blog to get further information and see tables to help make corn fungicide applications decisions.