Differential growth responses of dry peas (<i>Pisum sativum</i> L.) to gradient sulfate salinity stress in a controlled greenhouse setting

Dry pea (<italic>Pisum sativum</italic> L.), an important cool-season legume species, is prone to salinity stress. Previous research mostly focused on chloride salt-induced salinity (chloride salinity). In the Northern Great Plains, the major production region of dry pea in the U.S., soil salinity is predominantly induced by sulfate salts. The objective of this research was to determine how dry pea responds to sulfate-induced salinity. The seed of cultivar Agassiz was sown in the two sizes of cone-containers (big cone, 556 mL and small cone, 410 mL) and exposed to sulfate-salinity (0−20 dS·m⁻¹) through irrigation for four weeks at the seedling stage. Plants were sampled once weekly, and plant height, root and shoot growth, and visual damage were quantified. Plants treated with 5 dS·m⁻¹ showed no damage, which was similar to the non-stressed plants (0 dS·m⁻¹); however, plant growth was reduced by 50%−60% in tissue biomass in the 10 dS·m⁻¹ salinity treatment, while plant was severely damaged or dead in the 15 and 20 dS·m⁻¹ by week four. Among the evaluated traits, absolute water content, shoot fresh weight, and visual damage were mostly affected by the salinity stress. Plants grown in the big containers performed better than those in the small ones at 5–15 dS·m⁻¹ and after three or four weeks of saline exposure. This research provided useful information to dry pea growers and breeders on salinity management, particularly sulfate-salinity stress.