Assessing seed characteristics for improved winter survival of late-fall-seeded lentils

Late fall seeding (aka dormant seeding) can offer significant benefits over spring seeding, including earlier crop maturity, increased grain yield, and reduced risk of frost damage. However, this practice in Western Canada has not yet been adopted due to failures of canola crop establishment the following spring. A series of experiments was conducted on lentil (Lens culinaris Medik.) seeds to identify which characteristics are associated with winter survival and freezing tolerance. The lentil crop was used as a model system due to its variation in seed characteristics. We evaluated 38 genotypes for water uptake at +2 °C and freezing tolerance (LT₅₀, LD₅₀). Seed characteristics, including thousand-seed weight (TSW), surface area, volume, coat thickness, starch, protein and phenolic content, were quantified to determine their impact on water uptake and freezing tolerance. The total water uptake amount was positively and linearly correlated with TSW, seed surface area, volume and starch content, whereas it was negatively correlated with protein and phenolic content. Seeds that were frozen after imbibition exhibited lower germination percentages than seeds frozen without prior imbibition, indicating increased hydration is a key factor contributing to the loss of freezing tolerance. These findings suggest that seed morphological traits and biochemical composition modulate freezing tolerance primarily through their influence on water uptake dynamics. This research may help improve winter survival of fall-seeded spring crops, such as lentils, enabling a shift from conventional spring planting to late-fall seeding, potentially transforming crop establishment practice on the semi-arid Canadian prairies.