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Canola variety information
Canola Performance Trials (CPT) began in 2011 and
represent the next generation in variety evaluation for
Western Canadian canola growers. The trials were
designed to provide the following:
•
relevant, unbiased and timely performance data that
reflects actual production practices
•
comparative data on leading varieties and newly
introduced varieties
•
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 in 2013 were 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 delivered 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. There were 20 successful small
plot trials and more than 100 field-scale trials in 2013. The
trial sites were distributed based on seeded acres in
Manitoba, Saskatchewan and Alberta.
Small plot trials included popular varieties and varieties
that are newly introduced. The new small plot system
ensured:
•
all varieties are treated with appropriate commercially
associated herbicides and seed treatments
•
an independent third-party representative inspected all
trials
•
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. A check
variety 73-75 RR was included in all field scale trials in
2012
and 2013.
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 backgrounds in conducting field-scale research
trials performed the audits.
Small yield differences can easily be random variation
and, thus, are less likely 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 7 to 19 bu/ac in 2013. If variety A yielded 70
bu./ac. and variety B yielded 75 bu./ac., they would be
considered statistically the same. This result is based on a
confidence level that significant differences would occur
by chance less than 5 per cent of the time. A confidence
level of 10 per cent is sometimes used in statistical
analyses and would result in a slightly smaller LSD.
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 than 73-75 RR (5% level).
As results from more sites are combined, the statistical
power to determine if small differences are not due to
chance often improves quickly up to 15 to 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 higher number of sites increases the predictability that
the average yield differences would likely occur in other
fields in future years.
Where are CPT results available?
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.