Corn Product Yield Response to Fungicide – Scott City, KS

Trial Objective

  • The highest yielding corn products do not always have the best disease tolerance package, but that should not deter a grower from planting that product; however, there should be a plan in place to manage the risk of disease with a foliar fungicide.
  • The objective of this study was to evaluate the effect of an application of a foliar fungicide at tassel on the yield of six DEKALB® corn products.

Research Site Details

  • Six DEKALB® brand blend corn products were planted at 32,000 seeds/acre in a continuous no-till corn environment.
  • Each product was replicated three times in a small-plot set up. Two blocks were established as treated and untreated.
  • A total of 18 inches of rainfall was received during the growing season.
  • Irrigation was provided with a center pivot system with nozzles placed within the crop canopy.
  • There was very little disease pressure noted at this location. Staygreen ratings were similar between the treated and untreated plots.
  • 12 oz of Headline AMP® was applied at tassel with a hand boom delivering 15 gallons/acre. 2 oz of Headline AMP® was applied at tassel with a hand boom delivering 15 gallons/acre.

Understanding the Results

  • On average, the fungicide application improved yields across products.
  • The yield of DKC63-21RIB brand blend did not respond to the fungicide application as the untreated plots yielded the same as the treated plots.
  • On average, the staygreen rating was slightly better with the fungicide treatment vs. without treatment.
  • The yield response to the fungicide treatment was likely due to factors other than control of diseases since the staygreen ratings were similar in the treated vs. untreated blocks. The fungicide application may have been effective in reducing other plant stresses that helped to improve yield.

What Does This Mean for Your Farm?

  • Corn products may have different yield responses to the application of a foliar fungicide at tassel.
  • Generally, in a fully-irrigated environment, an application of a fungicide may be needed for control of Southern rust or grey leaf spot in Kansas.
  • Farmers should work closely with their local sales team in selecting corn products that have solid disease tolerance when planting continuous corn and may have to plan for a fungicide application at tassel. However, the best yielding products could be prone to certain foliar diseases and a planned application of a foliar fungicide can limit the risk of yield loss.
  • Similar trials will be conducted in the 2019 growing season.