Differentiate varietal performance of grain crops by environment. Provide producers with environment specific varietal recommendations. Add value to previous and continuing investments in regional variety trials of various crops in Saskatchewan.
For major crops in Saskatchewan, there is considerable investment in genetic improvement, variety development and evaluation. Varietal performance across environments is assessed by Regional Variety Trials (RVT) and published annually in the Saskatchewan “Varieties of Grain Crops” publication, to help producers with variety selection. Data is amalgamated across many trial sites over several years and yields are reported relative to a check variety. Other than a basic differentiation by soil zone, there is no differentiation of varietal responses to specific environmental conditions. A genotype by environment analysis of RVT data would be beneficial to identify varieties specifically adapted to various environmental conditions. Thus, the objective of this study was to conduct a supplemental analysis of long-term regional variety trial data of various crops to differentiate varietal performance by environment in Saskatchewan and to provide producers with environment-specific varietal recommendations.
RVT data was obtained for barley, oats, durum wheat, spring wheat, chickpeas, fababeans, lentil, and field peas. Each data set was analyzed separately. A mixed model analysis was first conducted to obtain BLUP-adjusted variety and trial mean yields, as an alternative approach to utilizing proportional yields relative to a check variety. A stress tolerance analysis and a yield stability analysis were then conducted for each crop using the adjusted yields. The stress tolerance and stability analysis methodology was also modified to assess varieties’ differential responses to varying levels of precipitation.
Overall, the supplemental analysis of RVT data provided results that would help producers in choosing varieties, especially if they are able to identify whether they are in a low- or high-yield potential environment. Knowing the relative stress tolerance or yield stability of varieties also provides a level of risk management for producers in variable environments. Precipitation was used as an environmental factor of interest to assess the feasibility of modifying the stress tolerance and yield stability analyses to examine specific environmental adaptations of varieties. The modified analyses proved to be insightful in identifying varieties that perform well under low, high, or variable levels of precipitation. Considering varieties are continually being developed, it would be beneficial to repeat the analysis regularly to include new and relevant varieties. The results presented in this report will be formatted to more effectively help guide producers in variety selection.