Evaluating Winter Canola Cultivars through a Detailed Analysis of the Oklahoma Winter Canola Variety Trials.

Cultivar selection is one of the most challenging but most critical decisions a grower makes each season.  While environmental conditions can influence the performance of individual cultivars, anecdotal evidence has suggested that certain canola cultivar systems have poorer performance compared to others.  To examine these observations, an analysis of the Oklahoma winter canola variety tests from 2008 through 2016was performed to determine if (1) varieties or hybrids performed better in Oklahoma and (2) to determine if variety performance differed in conventional tillage versus no-till systems.  Overall, cultivar performance significantly varied across the trial locations, indicating that the most suitable cultivar differed by location.  When evaluating variety versus hybrid performance in 2016, hybrids were not significantly different at the state level even though hybrids outperformed varieties in individual regions of the state.  The lack of a difference between varieties and hybrids was consistent across the 2008-2015 production seasons as well.  This indicated that there was no benefit of hybrids over varieties within Oklahoma production systems.  In a direct comparison between conventional tillage and no-till production systems, no difference was observed between individual cultivars.  Mercedes and P46W94 yielded the highest in both systems for variety and hybrids, respectively.  The primary difference between conventional tillage and no-till systems was the higher degree of variability for the no-till system.  These results indicated that evaluation of the hybrids and varieties together for individual locations, whether in a no-till or conventional tillage system, is justified.