Growth, yield, and yield stability of canola in the Northern Great Plains of the United States

Canola (Brassica napus L.) may diversify wheat-based cropping systems in the Northern Great Plains. However, agronomic adaptability and stability of high-yielding genotypes have not been widely evaluated over the diverse environmental conditions of South Dakota (SD). A 2-year field experiment was conducted in two contrasting environments (Brookings-eastern SD and Pierre-Central SD) to evaluate genotypes (10 in 2019 and 12 in 2020) for days to 50% flower, lodging, pods plant(-1), seed yield, 1000-seed weight, and yield stability. Seed yield for all genotypes in Brookings averaged 1961 and 1740 kg ha(-1), in 2019 and 2020, respectively, whereas at Pierre, yields averaged 1470 and 858 kg ha(-1). Seed oil concentration was greater at Brookings (456 and 406 g kg(-1) in 2019 and 2020, respectively) than at Pierre (356 g kg(-1) in 2019). The additive main effects and multiplicative interaction model (AMMI) evaluated eight genotypes across locations and years for genotype x environment (GE) interactions and stability. Environment was the most dominant cause of variation among genotypes, explaining 67.7%, 41.4%, and 45.7%, of the variations in pods plant(-1), 1000-seed weight, and seed yield, respectively, whereas GE explained most of the remaining variation. A combination of AMMI-1 biplots and AMMI stability values found variability in genotypic response to environments for seed yield suggesting cultivar recommendations should be environment specific.