b'objection is received for consideration at the annual meeting. Notiv. How much data goes into each yield value reported in the withstanding the above criteria, a variety can be retained in a tabletables?if a compelling case is made. In cases where both the breedingSingle site years of data will not be reported as it is often an institution and seed distributor wish to have a variety deleted fromunreliable indicator of performance. At least six site-years of RVT the table, removal can occur without a notification flag. Please noteyield data collected over two years are required prior to reporting that under normal circumstances, removal from a table does notthe figures in this publication for spring wheat, barley and oat. indicate variety cancellation has occurred.In 2023, due to more limited data for flax, triticale, winter wheat, durum, and fall rye publication of yield data will be allowed with Understanding Data in the Seed Guide Tables at least five site-years of RVT and/or registration data over two i. Yield and Non-Yield Traits growing seasons. When more limited data is used to generate yield Variety choice should never be based solely on yield performance, asdata for these crop types, its clearly indicated which varieties are its only one factor that affects net return. Producers are encouragedimpacted and a note of caution is listed in the footnote indicating to consider other characteristics such as maturity, plant height,that yield rankings among varieties can change substantially due to lodging and disease or pest resistance when deciding whichgrowing conditions.varieties to grow. The genetic yield potential of a variety is oftenFor new varieties, Overall Yield is often the first indication of masked by numerous factors, some of which can be controlledyield potential relative to the check. As additional data becomes through variety choice and others through astute agronomicavailable, yield performance is also expressed on the basis of management. Long term satisfaction with a variety is often relatedenvironmental productivity (Yield Test Categories of Low and to non-yield characteristics. High). Where there are less than the mandatory six site-years of data for a yield column (or five site-years of data for flax, triticale, ii. Check Varieties and Benchmark Check Varieties winter wheat, durum, and fall rye), an indication will be made that Producers have asked for additional checks in the regional varietythere is insufficient data to describe, symbolized by reporting an trials that reflect more commonly grown varieties. Starting inXX. Yield rankings among varieties can change substantially due 2018, two benchmark checks have been included in the trialsto growing conditions. To reflect these differences, results from a and reflect the two most popular varieties for the crop or markettest site that produced high yield in a particular year are placed into class during the previous year, based on crop insurance data. Thethe database for high yielding environments. The same site may benchmark checks will change as the popularity of varietiescontribute to the low yield category in a drought year when yields changes. Please note that there are instances when the benchmarkare low. check and the check variety are the same entry.Alberta covers a huge geographical area with many diverse Changes in check varieties required long and careful planning.growing conditions. Unfortunately, due to capacity issues and costs, At least three years of trials, in which the old and new checknot every area/region in Alberta has regional variety trial sites. As varieties are grown together, are required to provide sufficientsuch, yields are reported with low and high yield categories rather overlapping data. When there is a change in the check variety,than regions. It should also be noted that local variety performance variety performance is adjusted to the new check. Since the newmay differ significantly from the regional variety trial results check varieties are higher yielding than the previous checks anespecially in areas with limited or no regional variety trial data sites.overall decrease in the yield performance of all entries relative to theConsistent performance over all Yield Test Categories indicates new checks will occur.a variety has environmental responses similar to the check and may have good yield stability over a wide range of environments. iii. Variety ComparisonsScientific studies conducted on variety performance have shown Exercise caution when making yield comparisons among varieties.Yield Test Category analysis provides a more reliable indication of A varietys yield should only be directly compared to the standardyield performance than results organized by geographic region. reference check. Actual head-to-head testing between other varieties may not have occurred. Small plot agronomic trials arev. Types of Yield Data Reportedexpensive to grow and new varieties are registered every year. ItsYields are reported in many different formats. When selecting simply impractical to grow all varieties at the same time. Followinga variety, its important to understand what each yield column several years of data collection, the yield performance for arepresents. The yield comparison tables have several features:particular variety stabilizes relative to the check and further testing Overall actual plot yield of the check (bushels/acre) based on allis no longer required. Its for these reasons the check varieties aredata available to the testing program is provided along with the grown every year (e.g. AAC Brandon for CWRS wheat, AACnumber of station years of testingSynergy for barley) and that changes to these checks are infrequent. The range in plot yield for each Yield Test Category is definedThe Overall Station Years of Testing column provides an Actual plot yield of the check in each Yield Test Category isindication of the unbalanced nature of the dataset.reportedSpring 2024 55'