Projected global demand for small grain cereals emphasizes the need for sustainable intensi cation with higher crop yields. Field studies on so red winter wheat (Triticum aestivum L.) examined interactions among three fertilizer N rates, eight fungicide application strategies, and various cultivars grown in nine eld environments in Ontario, Canada. A synergistic response occurred when a high rate of N was applied with a fungicide strategy that controlled disease. Overall, compared to a typical N rate of 100 kg ha -1 and no fungicide, yields increased by an average of 1.45 Mg ha -1 when N was applied at 170 kg ha -1 with the most intensive fungicide treatment pooled across sites. is yield response varied from 0.80 to 2.11 Mg ha -1 depending on eld site and pooled across cultivars. Fungicide strategies that included a T2 ( ag leaf timing) or T3 (anthesis timing) produced the highest yields across environments, especially at the high N rate and in most cultivars. e crop response to fungicide depended on the susceptibility of the cultivar to foliar disease and whether the eld environment was favorable for disease development. High N rates increased spike numbers and kernels spike -1 , whereas fungicides mainly increased kernel weight and kernels spike -1 . Prior to an economic analysis, results from this study indicates clear potential for increasing wheat performance by intensifying management with increasing N and deploying fungicide application strategies, especially in some cultivars and in high yielding environments that may be favorable for disease development.

The addition of pyraclostrobin, pyraclostrobin/fluxapyroxad, pyraclostrobin/metconazole, trifloxystrobin/propiconazole, azoxystrobin/propiconazole, and trifloxystrobin/prothioconazole fungicides to glyphosate reduced disease incidence up to 19% and disease severity up to 4% compared with glyphosate alone. Fungicides evaluated can be safely mixed with glyphosate for corn production, but fungicide use was not associated with increased corn yield.