Annual canarygrass (Phalaris canariensis L.) is a specialty crop grown in Canada and the harvested grain is primarily used to feed wild and domesticated bird species. A field experiment was conducted at 5 locations in both 2012 and 2013 to study the response of annual canarygrass development and grain yield to the combined effects of fungicide (propiconazole + trifloxystrobin) and nitrogen (N) fertilizer, and to determine the minimum number of site years required to detect these effects. The experimental design was a split plot with fungicide application (none or fungicide) as the main plot and N application rate as the sub plot (10, 20, 30, 50, 70, 90 kg N·ha⁻¹). There was a linear increase of 14.5% in grain yield as the rate of N fertilizer increased. The fungicide application increased the grain yield 8.5% by increasing kernel density from 15 197 kernels m⁻² to 16 288 kernels m⁻². There was no interaction between the N rate and fungicide application. The application of a fungicide did not increase the responsiveness of annual canarygrass to N fertilizer. The lack of an interaction between N and fungicide application indicates that these two practices can be managed independently by annual canarygrass producers. To optimize grain yield producers should apply 50 kg N·ha⁻¹ and apply a fungicide to increase grain yield especially in regions where septoria leaf mottle is prevalent. The number of site years needed to consistently detect the impact of N and fungicide on the grain yield were 4 and 5 site years, respectively.