2017 Canola Variety Information
The 2017 CPT program was funded by Alberta Canola, SaskCanola and the Manitoba Canola Growers Association, with contributions from the BCGPA. 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/.
Canola Performance Trials (CPT) have been conducted since 2011 and represent the next generation in variety evaluation for western Canadian canola growers. The trials were designed to provide:
• Relevant, unbiased and timely performance data that reflects 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 Canola Council of Canada delivers the program on the committee’s behalf.
The CPT summaries provided in this factsheet are based on successful trials that did not show confounding factors during field inspections. The combination of drought and excessive moisture in different areas resulted in only 10 successful small plot trials in 2017. The small trial sites were distributed based on seeded acres in Manitoba, Saskatchewan and Alberta.
Small plot trials included a limited selection of popular and newly introduced varieties. The new small plot system ensured that:
• All varieties are treated with appropriate commercially associated 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.
Field scale comparisons add extra perspective for assessing consistency in variety performance. In 2015, the large scale comparisons were changed to assess the yield impact of selected shatter tolerant varieties under swath or straight cut harvest systems. In 2017, selected clubroot resistant varieties were also tested in large scale trials (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 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 background 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 comparing average zone yields for varieties in the small plot data, the least significant difference (LSD) ranged from 10 to 14% in 2017. This is based on a confidence level that similar differences would occur by chance less than 5% of the time. In the small plot design used, varieties are grouped by herbicide system, which means that the LSD shown strictly applies only to comparisons between a few varieties of the same herbicide system. Comparisons between many varieties or between different herbicide systems are still 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 different 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 to determine if small differences are not due to chance often improves quickly up to 15 -20 sites, and then marginally after that. This means that smaller differences are more relevant when all sites are averaged than just a few selected sites. Also, when there are a high number of individual sites for comparing two varieties, this increases the predictability that the average yield differences would likely occur in other fields in future years.
Where are CPT results available?
Results from zones with less than 5 sites of data are not shown in this publication due to limited reliability. Full results are available through an online interactive tool at www.canolaperformancetrials.ca. The interactive tool allows growers to explore many agronomic factors and to search for trial data in specific geographic areas near their farming operations. Details on management, operations and environmental data for each individual site will be reported online. The online tool has an economic calculator that includes the costs associated with growing the selected variety to assist growers in determining potential profitability.