Experimental and producer-reported data quantify the value of foliar fungicide to winter wheat and its dependency on genotype and environment in the U.S. central Great Plains

•We quantified the yield benefits of fungicide to wheat using plot and survey data.•Fungicide yield benefits (7.8 ± 15 %) were greater in wetter growing seasons.•Susceptible genotypes benefited more from fungicides (17 %) than resistant ones (6 %).•Fungicides improved stability and modified environment-adaptability of genotypes.•Fungicide yield benefits were greater (31 %) in the survey data. Foliar fungicides can account for a large portion of the yield gap in winter wheat (Triticum aestivum L.); however, their impacts on yield have been inconsistent in rainfed environments. We compiled a database of replicated field experiments and producer-reported fungicide and yield data from commercial fields to quantify the effects of fungicide application on winter wheat yield and yield stability. The database of field experiments (i.e., canopy level) included 56 non-inoculated environments spanning 12 growing seasons in eight Kansas locations, and was restricted to field experiments with direct comparisons between a foliar fungicide between Zadoks 40–55 and a side-by-side untreated control, resulting in 393 mean yield comparisons resulting from 3226 yield observations. The producer survey included genotype and fungicide management data from 654 commercial Kansas wheat fields cultivated across three growing seasons. Grain yield and weather conditions in the experimental and producer-reported database were similar, with seasonal precipitation ranging from ˜150 to 1035 mm and average grain yield of ˜3900 kg ha−1 with a ˜7000 kg ha−1 range. Foliar fungicide application resulted in 7.8 % average yield gain in the canopy-level data, ranging from −27 % to +97 %. Yield differences due to fungicide were strongly related to precipitation and to the ratio of precipitation and reference evapotranspiration (WS:WD) during the spring in the experimental data. Grain yield responsiveness to fungicide associated with the responsiveness of green canopy cover, kernel weight, biomass, and harvest index. Analysis of covariance suggested that grain yield usually decreased with increases in disease susceptibility in the absence of foliar fungicides; however, yield-disease relationships were either neutral or positive in the presence of fungicides. Average yield gain for resistant varieties was ˜166 kg ha−1 (5.6 %), which was lower than for intermediate (˜199 kg ha−1; 6.9 %) or susceptible genotypes (˜598 kg ha−1; 16.9 %). Foliar fungicides increased yield stability across genotypes at th