Seed Priming and Smoke Water Effects on Germination and Seed Vigor of Selected Low-Vigor Forage Legumes

A commercial solid matric priming method and an osmotic priming method were used to measure seed priming responses of birdsfoot trefoil, kura clover, and sericea lespedeza. Differences were not observed using standard germination tests, but both priming methods show potential for increased germination rate (P>0.05). Conflicting results for matric and osmotic priming were found in terms of seed storage potential after priming, with matric primed seeds showing higher (P<0.05) germination after accelerated aging and osmotic primed seeds showing significant lower germination(P<0.01). Birdsfoot trefoil benefited from priming, but responses varied by priming treatment, while kura clover showed less response to both priming treatments. In a field study comparing matric primed vs. unprimed seedling emergence, matric priming effects were small and these data suggest that solid matrix priming may be unlikely to improve the field establishment of either species.

Aqueous smoke solutions were also tested for effect on seed germination. Differences in final germination percent due to solution type (after exposure to liquid smoke solutions for 10- or 45-min) were not observed. Highest concentration of the 10-min solution treatment reduced (P<0.05) birdsfoot trefoil germination. Greater germination was observed only for 'Perfect Fit' kura clover treated with low or intermediate concentrations of either solution. High concentrations of 10-min smoke water increased time to 50% germination (T50) for all seeds, but some reduction in T50 occurred for kura clovers treated with low (5%) solution concentrations. The 45-min treatments had little effect on germination rates. Applying aqueous smoke solution to seeds at germination did not improve germination responses of these forage legume species.