Imbibition of seed of dry bean cultivars stored under high or low temperature and relative humidity conditions

Abstract

An investigation was conducted to evaluate seed hardness of dry bean cultivars per line from different planting dates (PD) and stored under high or low controlled temperature and relative humidity (RH) conditions. Nine dry bean cultivars per line were planted at 6 dates, 7 days apart, at Scottsbluff, NB, and harvested at physiological maturity. A split-split-plot design was used with temperature and RH combinations as main plots, PD as sub-plots, and cultivars per line as sub-sub-plots. Seed samples (40 seeds) of each entry from each PD were stored in incubators at 16°C or 45°C, each combined with 22–24% or 98–100% RH, for 21 days. Seed weight after storage, seed weight after soaking for 8 h, and number of imbibed seeds were measured to evaluate imbibition and seed hardness. Seeds stored at 98–100% RH showed a linear increase in weight after storage and weight after soaking with later PDs. The numbers of imbibed seeds of beans stored at 16°C and 22% RH showed a linear decrease with later PDs. Seeds of white beans, particularly cultivar ‘GN Emerson’, stored at 16°C and 22% RH had greater weight after soaking and more imbibed seeds than the pinto cultivars. RH had a greater effect than temperature on increasing (high RH) or decreasing (low RH) seed weight after storage, seed weight after soaking and number of imbibed seeds. Storage conditions, cultivars per line and planting dates affected imbibition, and therefore hardness of bean seeds.