Effects of seed priming and irrigation on plains rough fescue (Festuca hallii) seed germination and biomass production

There has been increasing interest in seeding Festuca hallii in native plant mixtures for land reclamation and rangeland re-vegetation. However, its seed production is unstable constraining for its use. Therefore, improvement of seed production and increasing forage yield are of interest to many researchers. Objectives of this research were to assess effects of smoke priming on seed germination and early seedling growth of 12 F. hallii populations and evaluate smoke priming and water treatment on their growth and biomass production under greenhouse or field conditions. In this study, serial dilutions of aqueous smoke solutions were applied for seed priming. In addition, seeds of the two F. hallii EcovarsTM was also primed with iron-hydrogen peroxide (H2O2). Total germination, time to 50% of total germination (T50) and seedling vigor were measured. Seedlings after smoke primed treatments were transplanted to the College of Agriculture and Bio-resources greenhouse and field plot at the Livestock Forage Center of Excellence to estimate plant growth and biomass production under three water levels (75 mL water every three days, 75 mL water every six days, and 50 mL water every six days in greenhouse or ‘Rainout shelter’, ‘Control’, and ‘Irrigation’ in field). Results showed that high smoke concentrations reduced seed germination, but low smoke concentrations neither increase total germination percentage nor reduce germination time. Radicle length was longer for certain F. hallii populations after 1/1000 v/v aqueous smoke solution priming. Total germination of the two EcovarsTM was increased (p = 0.02) by 9% in 3.125% H2O2 treatment. In our greenhouse study, plant height or tiller per plant increased (p = 0.04 and 0.0303) after priming with 1/1000 v/v or 1/100 v/v smoke solutions, while almost no change was found for above-ground and below-ground biomass. In our field study, plant height of ‘Turtleford’ population (p = 0.027) and tiller per plant of ‘Unity’ population (p = 0.025) were increased by smoke priming while other populations were not affected. Tiller per plant increased under ‘Irrigation’ (p = 0.0002) for all populations. In conclusion, seed priming with lower concentration of aqueous smoke solution did not promote seed germination of F. hallii, but early radicle growth was enhanced in certain populations. Low concentration of Iron- H2O2 can promote seed germination of F. hallii populations. In greenhouse, smoke priming increased plant height and tiller per plant for all populations. In addition, higher water supply can improve plant growth and biomass production except Kernen on above-ground biomass. For the first production year in the field, smoke priming only increased plant height for ‘Turtleford’ and tiller per plant for ‘Unity’. ‘Irrigation’ improved tiller per plant of 12 F. hallii populations