Methods

This experiment was set up using a split-plot design. The main plots used the soil temperature treatment and the cultivars were randomized as subplots within the main plots, Figure 4. There were three replicates at each of the four sites (Beaverlodge, Edmonton, Lacombe, and Lethbridge). The order of the main plots was randomized in each replicate. Five of the cultivars that were selected for this trial include CWRS cultivars that are commonly used across Alberta, and the other five cultivars are early maturing and at or near commercialization.

Prior to the beginning of the trial soil tests were performed at each site to determine what level of fertilization was needed to achieve the expected average yield at each site.

Every day at 10:00 am a soil temperature probe was used in 4 spots across each replication of the trial. Once the temperature reading was either 2°C or 8°C the seeding of those plots commenced the next day. Seeding dates ranged from early April to mid-May. Plot sizes varied between sites from 3.66m wide by 10m long in Beaverlodge to 1m by 3m in Edmonton. All yield data was converted to kg/ha for equivalent data analysis.

The emergence date for each individual plot was called when clear, visible rows were present; shortly after that, a pre-marked area of 1m by 2 rows by two spots underwent plant counts in each plot. During the growth of the plants, Haun scale assessments were taken once throughout the growing season. Haun scale assessments are used to determine the number of leaves on the main stem of the wheat plant; the most recent leaf is counted as 0-1 depending on how long the leaf is compared to the second most recent leaf. An example would be an HSA of 3.5, this would mean that three leaves have fully emerged and the fourth leaf is only half as long as the third leaf. Vigor ratings of 1-5 were recorded at two growth stages: Zadoks 31 and Zadoks 37. Head emergence, anthesis, and maturity dates were recorded for each plot. Plant counts were conducted at maturity in the same pre-marked spots to determine the amount of tillering that occurred. Once the plants in the plot reached maturity the maturity date was recorded in Julian days and then harvest occurred shortly after. Yield, dockage, test weight, and protein were recorded during or after harvest. Final yield data was corrected to 14.5% moisture as to standardize yield data from each individual plot. Harvest took place between the end of August and the end of September.