53 www.seed.ab.ca | spring.2019 productivity (Yield Test Categories of Low, Medium, High and Very High). Yield rankings among varieties can change substantially due to growing conditions. To reflect these differences, results from a test site that produced high yield in a particular year are placed into the database for ‘high’ yielding environments. The same site may contribute to the ‘low’ yield category in a drought year, when yields are low. Consistent performance over all Yield Test Categories indicates that a variety has environmental responses similar to the check and may have good yield stability over a wide range of environments. Scientific studies conducted on variety performance in Western Canada have shown that Yield Test Category analysis provides a more reliable indication of yield performance than results organized by geographic region. The yield comparison tables have several features: •  Overall actual yield of the check (bushels/acre) based on all data available to the testing program is provided along with the number of station years of testing. • The range in yield for each Yield Test Category is defined. • Actual yield of the check in each Yield Test Category is reported. •  For varieties with sufficient data, the Overall Yield and performance in each Yield Test Category is expressed relative to the check. To make effective use of the yield comparison tables, producers should set a realistic yield target for the season and determine where it fits within the Low, Medium, High and Very High Yield Test Categories. This approach facilitates matching of variety choice to expected productivity levels and is similar to that used when making decisions on other levels of inputs. Please note that the actual yield levels indicated are from small plot trials, which may be 15 to 20 per cent higher than yields expected under commercial production. Maturity Ratings As is the case for yield, growing conditions have a tremendous influence on the date of maturity. For example, a variety of CWRS wheat may mature in 98 days in Lethbridge, but take 103 days in Edmonton. Likewise, a two day difference in maturity between varieties in southern Alberta may amount to a five day difference in a more northerly location. To take this into account, maturity is expressed using a six category scale: Very Early, Early, Medium, Late, Very Late, and in rare instances Extremely Late. To aid producers with this relative scale, the average number of days to maturity for the check is reported. Note that this scale is different for each crop type. For example, an early barley variety will mature much earlier than an early flax variety. Seed Size and Plant Populations Seed size within a crop kind will vary from variety to variety, requiring adjustment of seeding volumes to achieve desired plant populations. Some of the tables provide an average 1000 kernel weight (TKW) which can be used as a guide for variety differences. The best approach is to determine the 1000 kernel weight of the seed to be planted, germination rate, emergence mortality, and in the case of fall seeded crops, an estimate of winterkill. For more information and user-friendly seeding rate calculators that take into account these and other considerations, please see www.agric.gov.ab.ca/app21/ldcalc. Plant Breeders’ Rights Plant Breeders’ Rights (PBR) are a form of intellectual property rights by which plant breeders can protect new varieties in the same way an inventor protects a new invention with a patent. In 2015, Canada amended the PBR Act to bring it into conformity with UPOV 91. Varieties protected under the previous legislation (UPOV 78) are indicated with the logo , whereas those protected under the new legislation that are shown with a new logo . The use of the ▲ logo indicates that an application for PBR has been accepted and the variety has provisional protection. For more information on Plant Breeders’ Rights, please see www.pbrfacts.ca or the Canadian Food Inspection Agency website at www.inspection.gc.ca. 2 5 0 - 7 8 2 - 7 8 2 0 w w w. s p g r a i n . c a i n f o @ s p g r a i n . c a Traditional Values. Modern Approach. Wheat: Thorsby CWRS AAC Brandon Go Early CWRS AAC Redwater CWRS AAC Penhold CPS Viewfield VB AAC Connery Peas: CDC Carver AAC Peace River Barrhead Oats: CDC Haymaker CDC Ruffian CS Camden Barley: CDC Austenson CDC Maverick South Peace Grain Full service seed conditioning facility Multiple bagging options available Licensed grader on-site Certified Seed Products EST. 0703 South Peace Grain Traditional Values. Modern Approach.