Is there an economic benefit to foliar application of fungicide to alfalfa?

by Sara Berges,
Allamakee SWCD

With fungicide application to any crop, it is important to select opportunities where the probability of economic return is greatest. Iowa State University has conducted six years (2012-2017) of research looking at the economic and yield impact of fungicide application to alfalfa. Harvest schedules followed a four-cut system.  On average, first crop provided a higher percent yield response to a foliar fungicide application than for later crops.   This is because spring usually favors alfalfa diseases due to higher rainfall and there is higher yield potential for first crop than for later crops. In dry years, disease incidence was low and application of fungicide provided little yield response and often resulted in an economic loss. 

It’s also important to factor in hay price in addition to yield. A 10 percent yield increase from a fungicide application does not add as much value to $80 per ton hay as it would to $200 per ton hay. Before applying fungicide, take into consideration the potential yield response plus hay price to determine the profitability. There may not be an economic benefit.  Applying fungicides without much thought to yield and environmental conditions does not follow proper stewardship of our land or resources.