Variation in yield, starch, and protein of dry pea grown across montana

Pea (Pisum sativum L.) has long been an important component of the human diet, providing an excellent source of protein. In addition to its protein, pea starch, especially resistant starch (RS), has received an extensive attention in food industries in recent years. We evaluated nine pea cultivars varying in cotyledon color, grain weight, maturity group, and phenology planted at five locations with diverse climatic conditions across Montana in 2013 and 2014 to assess genetic and environmental factors affecting their yield, protein, RS, and total starch (TS). Grain yield varied from 982 to 5951 kg ha^–1, RS content ranged from 5 to 53 g kg^–1, and protein from 159 to 251 g kg^–1. Statistical analysis showed that environment was the most important driving factor in grain yield, protein, and TS determination whereas RS content was mainly determined by cultivar. Drought at all phenological stages reduced pea yield and different cultivars tended to respond differently. Yield was positively correlated with protein, implying a potential to select/breed a cultivar with higher yield and protein. Protein was negatively correlated with TS, thus protein- or starch-type cultivars may be bred for different end users. Compared to other cultivars tested, DS Admiral was the most promising one with above average yield, protein, and RS.