In 2011, we set up three commercial-scale, on-farm fungicide tests in fields of yellow and white corn in western Kentucky. It was challenging to balance scientific standards of experimental design with the need to keep it doable for the aerial applicator and the producer. Nevertheless, we did it and, to my surprise, a single fungicide application resulted in 20+ bushel yield increases in two of the three tests. 

We also observed improved stalk strength in one of the trials. Surprisingly, all of this occurred in the absence of significant disease pressure. 

Please note that, in one of those two trials, the fungicide application included an insecticide, so we can’t be sure how much of the yield increase was due to the fungicide.  In any case, the results were impressive, and we wanted to repeat those experiments to see how robust our results were.

This past summer, we were fortunate to have the cooperation of several large grain producers in West Kentucky.  Consequently, we were able to successfully complete three commercial-scale, replicated fungicide trials.

Read more about the Results from 2013 On-Farm Fungicide Trials in Corn.

Across the country, corn pathologists agree that fungicides are most likely to provide a benefit under conditions of moderate to severe pressure from key disease diseases.  Our results from 2013 affirm that guideline.  This is because two of our three trials had enough disease pressure that fungicide application very likely provided an economic benefit in corn grown for grain, especially for the test in white corn. 

In contrast, in 2011, we saw that substantial increases in yield and stalk health were sometimes (but not always) possible from a fungicide application even in the absence of significant disease.  This is consistent with the experience of some producers, who believe they are getting substantial agronomic benefits rather consistently.  

If a producer is still undecided about whether fungicide applications have a place in their production system, they should consider leaving several untreated strips in an otherwise treated field.  This will help them see for themselves whether yield is increased under their farming conditions.