b'basis of environmental productivity (Yield Test Categories ofprior to inclement weather will result in the retention of high Low, Medium, High and Very High). Where there are less thanfalling number.Thus, the use of earlier maturing varieties eight site-years of data for a yield column, an indication willwith Good or Very Good pre-harvest sprouting resistance be made that there is insufficient data to describe, symbolizedin short-season areas is usually an effective management by reporting an XX. Yield rankings among varieties candecision for maintaining high quality. A rating for pre-harvest change substantially due to growing conditions. To reflectsprouting resistance is provided for most of the reported these differences, results from a test site that produced highwheat varieties based on controlled environment conditions. yield in a particular year are placed into the database forThese ratings reflect genetic differences. Varieties with Good high yielding environments. The same site may contributeor Very Good pre-sprouting resistance will normally retain to the low yield category in a drought year, when yields aretheir falling number for longer periods of time under cool, wet low. Consistent performance over all Yield Test Categoriesharvest conditions. However, even these varieties will initiate indicates that a variety has environmental responses similargermination when mature and exposed to prolonged conditions to the check and may have good yield stability over a widefavourable to sprouting, resulting in falling number reductions. range of environments. Scientific studies conducted on varietyNote that falling number can be reduced without visible signs of performance in Western Canada have shown that Yield Testsprouting.Category analysis provides a more reliable indication of yield performance than results organized by geographic region. Seed Size and Plant PopulationsThe yield comparison tables have several features: Seed size within a crop kind will vary from variety to variety, Overall actual yield of the check (bushels/acre) based on allrequiring adjustment of seeding volumes to achieve desired data available to the testing program is provided along withplant populations.Some of the tables provide an average 1000 the number of station years of testing.kernel weight (TKW), which can be used as a guide for varietyThe range in yield for each Yield Test Category is defined. differences.The best approach is to determine the 1000 kernelActual yield of the check in each Yield Test Category isweight of the seed to be planted, germination rate, emergence reported. mortality, and in the case of fall seeded crops, an estimate of For varieties with sufficient data, the Overall Yield andwinterkill.For more information and user-friendly seeding rate performance in each Yield Test Category is expressedcalculators that take into account these and other considerations, relative to the check. please see www.agric.gov.ab.ca/app21/ldcalc. To make effective use of the yield comparison tables, producers should set a realistic yield target for the season andPlant Breeders Rightsdetermine where it fits within the Low, Medium, High and VeryPlant Breeders Rights (PBR) are a form of intellectual property High Yield Test Categories. This approach facilitates matchingrights by which plant breeders can protect new varieties in the of variety choice to expected productivity levels and is similarsame way an inventor protects a new invention with a patent. In to that used when making decisions on other levels of inputs.2015, Canada amended the PBR Act to bring it into conformity Please note that the actual yield levels indicated are from smallwith UPOV91.Varieties protected under the previous legislation plot trials, which may be 15 to 20 per cent higher than yields(UPOV78) are indicated with the logo, whereas those expected under commercial field production.protected under the new UPOV91 legislation that are shown with the new logo.For more information on Plant Breeders Maturity Ratings Rights, please see www.pbrfacts.ca or the Canadian Food Based on feedback from producers, the six category scale forInspection Agency website at www.inspection.gc.ca.maturity (Very Early, Early, Medium, Late, Very Late, Extremely Late) has been replaced with average differences in days,Varieties Reported in the Tablesrelative to the check. Be aware that these are averages fromA variety must be registered to appear in the tables.Publication several years over the vast agricultural production area ofnormally occurs after two years of testing; however, entries are Alberta and growth environment has a tremendous influence onaccepted with the understanding that testing will occur for at maturity dates.Hot, dry conditions will compress the reportedleast three years.When there are limited data for a new variety, maturity differences just as cool, wet conditions will expandyield information may only appear in the Overall Yield column.them. For example, a variety of CWRS wheat may mature in 98An XX is reported in any column when there is insufficient days in Lethbridge, but take 103 days in Edmonton. Likewise,data. Single year data will not be reported as it is often an a variety that is on average two days later maturing across theunreliable indicator of performance.province may be only one day later in southern Alberta butVarieties without pedigreed seed production in Alberta could be three or more days later in a northern location. within the past two years, following five years of full registration Falling Number and Resistance to Pre-harvest Sprouting to facilitate adoption, will be flagged for removal from the tables. Falling number is a measurement of the extent to whichAfter the variety has been flagged for removal for one year, it endosperm starch in the seed has been metabolized to simplemay be removed from the tables unless an objection is received sugars during the germination process. There are manyfor consideration at the annual meeting.Notwithstanding interrelated genetic, environmental and management factorsthe above criteria, a variety can be retained in a table if a that influence seed germination prior to harvest. In general,compelling case is made.In cases where both the breeding conditions in which the crop is harvested soon after maturityinstitution and seed distributor wish to have a variety deleted Spring 2020 61'