b'when deciding which varieties to grow. Long term satisfactionsimilar to the check and may have good yield stability over a with a variety is often related to non-yield characteristics. wide range of environments. Scientific studies conducted on Producers have asked for additional checks in the regionalvariety performance in western Canada have shown that Yield variety trials that reflect more commonly grown varieties.Test Category analysis provides a more reliable indication of Starting in 2018, two benchmark checks were included in theyield performance than results organized by geographic region.trials and reflect the two most popular varieties for the cropThe yield comparison tables have several features:or within a market class during the previous year, based on Overall actual yield of the check (bushels/acre) based on all crop insurance data. There are instances when the benchmarkdata available to the testing program is provided along with check and the check variety are the same entry. The benchmarkthe number of station years of testing. checks will change as the popularity of varieties changes.The range in yield for each Yield Test Category is defined.Exercise caution when making yield comparisons among Actual yield of the check in each Yield Test Category is varieties. A varietys yield should only be directly comparedreported.to the standard reference check. Actual head-to-head testingFor varieties with sufficient data, the Overall Yield and between other varieties may not have occurred. Small plotperformance in each Yield Test Category is expressed agronomic trials are expensive to grow and new varieties arerelative to the check.registered every year. Its simply impractical to grow all varietiesTo make effective use of the yield comparison tables, at the same time. Following several years of data collection,producers should set a realistic yield target for the season and the yield performance for a particular variety stabilizes relativedetermine if it fits within the Low or High Yield Test Categories. to the check and further testing is no longer required. Its forThis approach facilitates matching of variety choice to expected these reasons the check varieties are grown every year (e.g.productivity levels and is similar to that used when making AAC Brandon for CWRS wheat, CDC Copeland for barley)decisions on other levels of inputs. Please note the actual yield and changes to these checks are infrequent. The Overalllevels indicated are from small plot trials, which may be 15 to Station Years of Testing column provides an indication of the20 per cent higher than yields expected under commercial field unbalanced nature of the dataset.production. In the January 2022 publication, readers will notice the spring wheat check has changed from Carberry to AAC Brandon, theMaturity Ratingsbarley check has changed from AC Metcalfe to CDC Copeland,Based on feedback from producers, the six-category scale for and the oat check has changed from CDC Dancer to CS Camden.maturity (Very Early, Early, Medium, Late, Very Late, Extremely These changes required long and careful planning. At leastLate) has been replaced with average differences in days, three years of trials in which the old and new check varietiesrelative to the check. Be aware these are averages from several are grown are required so there is sufficient overlapping data.years over the vast agricultural production area of Alberta Readers will notice that there are fewer station years of testingand that growth environment has a tremendous influence on for the new check varieties. Data for the currently testedmaturity dates. Hot, dry conditions will compress the reported varieties reflect data generated based on the varieties whichmaturity differences just as cool, wet conditions will expand have generally been grown during the past three years. Data forthem. For example, a variety of CWRS wheat may mature in 98 the previously tested varieties were adjusted relative to the yielddays in Lethbridge, but take 103 days in Edmonton. Likewise, difference between the old and new check from the historicala variety that is on average two days later maturing across the database. Since the new check varieties are higher yielding thanprovince may be only one day later in southern Alberta but the previous checks, readers will notice an overall decrease incould be three or more days later in a northern location.the yield performance of all entries compared with historical publications.Falling Number and Resistance to Pre-harvest At least six site-years of yield data collected over two yearsSproutingare required prior to reporting the figures in this publication.Falling number is a measurement of the extent to which For new varieties, Overall Yield is often the first indication ofendosperm starch in the seed has been metabolized to simple yield potential relative to the check. As additional data becomesugars during the germination process. There are many available, yield performance is also expressed on the basis ofinter-related genetic, environmental and management factors environmental productivity (Yield Test Categories of Low andthat influence seed germination prior to harvest. In general, High). Where there are less than six site-years of data for a yieldconditions in which the crop is harvested soon after maturity column, an indication will be made that there is insufficient dataprior to inclement weather will result in the retention of high to describe, symbolized by reporting an XX. Yield rankingsfalling number. Thus, the use of earlier maturing varieties among varieties can change substantially due to growingwith Good or Very Good pre-harvest sprouting resistance conditions. To reflect these differences, results from a test sitein short-season areas is usually an effective management that produced high yield in a particular year are placed intodecision for maintaining high quality. A rating for pre-harvest the database for high yielding environments. The same sitesprouting resistance is provided for most of the reported may contribute to the low yield category in a drought year,wheat varieties based on controlled environment conditions. when yields are low. Consistent performance over all Yield TestThese ratings reflect genetic differences. Varieties with Good Categories indicates a variety has environmental responsesor Very Good pre-sprouting resistance will normally retain Spring 2022 61'