The ISU opinion around fungicide applications has not been consistent with real world results. I don't know why that is and I don't really care to speculate why it is. Absent disease pressure, two years ago check strips ranged from 12-23 bushels across 800 acres on our farm. Nearly zero visible disease pressure. What fungicides do is not limited to disease mitigation. The SDHI component. in my opinion, is more important as it extends grain fill substantially allowing for more grain weight. Then you have the benefit of slowing down respiration as well, which is a very big deal when you get into a stretch of warm nights like we're going to have here over the next week or so.
It's a multi-faceted application that does a number of things and can pay in multiple ways beyond just controlling disease.