8 years, up to 172 trials

Fungicides tested: Headline, Stratego, Quilt and Quadris. All fungicides were applied at VT (tasseling) or at R1 (silking).

Average yield range: 164-197 bu./acre.

Yield difference between fungicide-treated and untreated plots: In 28-48% of the trials, yield was higher in the untreated plots than in the fungicide-treated plots. Remember the piano graphs you see at meetings? These clearly show how highly variable yield responses are to fungicides.  

Average yield difference between fungicide-treated and untreated plots: 3.6-6.2 bu./acre.

Average yield difference between fungicide-treated and untreated plots when foliar disease levels are low (<5%): 1-5bu./acre.  

Average yield difference between fungicide-treated and untreated plots when foliar disease levels are higher (> 5%): 7-10 bu./acre.