Abstract
<jats:p>Pea (Pisum sativum L.) is an important source of protein, with a large portion of production occurring in North America across the northern and central Great Plains (GP). To understand the influence of the environment (site-year) across this landscape and its interaction with different pea cultivars, a three-year multi-location trial was conducted across the GP. The objectives were to quantify cultivar and environmental variability for pea grain N concentration and grain yield in order to utilize stability indices to evaluate if trait means are associated with trait stability. The mean grain N concentration was 39.6 g kg-1, and the mean grain yield was 3130 kg ha-1 across all environments and cultivars. The largest proportion of variance explained for grain N concentration was due to environment (70.5%), followed by the genotype-environment interaction (18.9%) and cultivar (10.5%). Environment explained 97.1% of grain yield variation. Cultivar exerted a 21-fold greater effect on grain N concentration than yield, suggesting cultivar selection is crucial for grain quality optimization, specifically grain N concentration. Additive main effect and multiplicative interaction (AMMI) and best linear unbiased prediction (BLUP)-based models demonstrated that trait means are not associated with trait stability among cultivars. The study reveals that environment explains most of the grain N concentration and yield variation while detailing the importance of cultivar to the formation of grain N concentration and stability. This study provides a framework for future cultivar evaluation trials to utilize stability indices to increase pea cultivar evaluation robustness across the GP region.</jats:p>