Farm Journal Test Plots Answer Three Questions on Foliar Fungicide ROI

A decade ago, few farmers thought about using a foliar fungicide on soybeans. Then fungicide prices declined, crop prices had a nice run and yields continued to increase. Diseases and insects didn’t let up, so fungicide use intensified. 

Since 2015, the Farm Journal Test Plots have studied fungicide use, initially as it relates to disease pressure. From there, Farm Journal Field Agronomists Missy Bauer and

Ken Ferrie have more closely examined the plant health response and where the yield benefit actually comes from.

In 2019, foliar fungicide use in the Michigan test plots increased yield by 3.47 bu. to 4.7 bu. per acre versus the control. The average four plot locations in southern Michigan was 4.23 bu. per acre. Over the course of four years (2015 to 2019) that average increased to 4.91 bu. per acre (with a range of 5.9 bu. per acre in 2015 to 2019’s average).