Table 1. Vegetative growth stages in corn
Drs. B. Deen, D. Hooker and J. Nasielski of the University of Guelph reviewed several of the long-term nitrogen corn trials from the Elora and Ridgetown Research Stations to look at what factors most influenced the most economical rate of nitrogen (MERN) in Ontario grain corn. Rainfall between V7 - VT corn stages (see Table 1), had the greatest correlation to the actual MERN each year. This timing is usually between mid-June and mid-July.