Non-Peer ReviewedThe variable weather conditions and climatic zones in western Canada often lead to
differences in regional adaptation of cultivars that must be identified so that cropping risks can
be reduced and returns maximized. Regional testing programs have been developed to provide a
database for the determination of average grain yields for target areas, but in recent years the
number of new cultivar releases has increased dramatically and the available resources for
regional testing has been reduced. Attempts to deal with these problems have lead to web based
systems that allow visitors to make head-to-head comparisons among cultivars of interest.
However, the limitations associated with the comparison of means persist in these systems and
considerable information of importance remains buried in the data files. This paper describes an
interactive web-based model for head-to-head cultivar grain yield comparisons that calculates
relative yields based on the growing season environmental potential at any prospective location
in western Canada. By adapting and combining the databases from cooperative and provincial
testing programs this decision-making tool also offers the opportunity to make plant breeding
programs more effective while reducing the need for extensive post-registration regional testing
