82 | Advancing Seed in Alberta canola – performance trials and grower directory 2018CanolaVarietyInformation CANOLA PERFORMANCE TRIALS (CPT) have been conducted since 2011 to provide variety evaluation for western Canadian canola growers. The trials were designed to provide: •  Relevant, unbiased and timely performance data including large scale plots that reflect actual production practices. •  Comparative data on leading varieties and newly introduced varieties from participating companies. •  Detailed reporting on agronomic characteristics such as yield, height, lodging, maturity and economic performance, and site specific performance variables including weather, soil type, crop nutrition, seeding and harvest management. The CPT trials are conducted under the guidance of a governance committee that approves participating varieties, protocol design, data collection, analyses, reports and finance management. The 2018 CPT program was funded by Alberta Canola Producers Commission, SaskCanola and the Manitoba Canola Growers Association, with contributions from the BC Grain Producers Association. The Canola Council of Canada delivers the program on their behalf. You can learn more about the CPT program and the CPT Technical and Governance Committee in the Canola Variety Selection Guide, available at www.canolaperformancetrials.ca/. The CPT summaries provided here are based on successful trials that did not show confounding factors during field inspec- tions. The combination of drought and other factors resulted in only 18 successful small plot trials in 2018. The small trial sites were regionally distributed based on seeded acres in Manitoba, Saskatchewan and Alberta. There were 42 locations of large scale trial data accepted in 2018. Small plot trials included a limited selection of popular and newly introduced varieties. The small plot system ensures that: •  All varieties are treated with appropriate commercially associ- ated herbicides and seed treatments; •  An independent third party representative inspected all trials; and, •  Harvest occurred at the most appropriate time to minimize harvest losses due to maturity differences. A separate small scale straight cut test is also included to compare varieties marketed for straight cutting. Field scale comparisons add extra perspective for assessing variety performance. Starting in 2015 large scale comparisons were added and they must meet standard protocols. In 2018 there were 3 large scale comparison tests: shatter tolerant varie- ties under swath (standard) or straight cut harvest systems; and comparison of selected clubroot resistant varieties (but not on clubroot infested land). To ensure quality data and statistical analysis, the CPT technical committee established protocols and developed research plot designs. Performance objectives were established to provide guidelines on timely field operations and data collection. All small plot sites were inspected to verify that guidelines were followed for fair comparisons among the varieties tested. Audits of field scale projects give growers the confidence that the protocol was conducted in a scientifically sound manner and that comparisons are appropriate. Qualified professionals with extensive back- ground in conducting field scale research trials performed the audits. Small yield differences can easily be due to random variation and thus are unlikely to be real effects of varieties. When compar- ing average zone yields for varieties in the small plot data, the least significant difference (LSD) ranged from 6 to 13% in 2018. This is based on a confidence level that similar differences would occur by chance less than 5% of the time. Comparisons between many varieties or between different herbicide systems are valid but the LSD would be larger. More importantly, comparisons between varieties within the same herbicide system reveal only genetic differences, whereas variety comparisons from differ- ent herbicide systems involve the net effect of both genetic and herbicide effects (weed control + crop tolerance). When comparing variety yields in the field scale summaries, an asterisk (*) indicate yields that are statistically different (5% level) using the paired t-test. As you combine results from more sites, the statistical power