Comparative Relative Maturity (CRM) is a standardised measure used to compare how long it takes different corn hybrids to reach physiological maturity—specifically, when the grain reaches black layer.
PAC 660 has a CRM rating of 120 days*, placing it in the medium to long maturity category. It’s well suited to regions with longer growing seasons, where maximising yield potential is a key priority.
*Although CRM is expressed in “days”, it’s not a literal count of calendar days. Instead, it reflects a relative measure based on accumulated heat units (growing degree days or GDDs) under standardised conditions. So, a 120 CRM hybrid like PAC 660 typically matures later than hybrids with lower CRM values, but the actual number of days to maturity can vary by environment.
