Effects of Irrigation, Seed Coating, and Seeding Rate On Seedling Establishment and Aboveground Biomass Productivity of ‘Prosper' Summer-Dormant Tall Fescue.

Establishment of summer-dormant cool-season grasses may be difficult in semi-arid environments of the southern Great Plains of USA because of unpredictable autumn precipitation. We evaluated effects of seeding rate (11, 17, 22, 28, and 34 kg ha^-1), Zeba® seed coating (coated and non-coated), and supplemental irrigation on seedling establishment and aboveground biomass productivity in subsequent growing seasons of ‘Prosper’ summer-dormant tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] at Vernon, TX during 2007-2009 (Run 1) and 2008-2010 (Run 2). Full irrigation was defined as amount equal to long-term average monthly precipitation (a sum for September base precipitation, and October-November). Reduced irrigation was defined as 50% of the amount needed to meet the long-term monthly average precipitation, except for September base irrigation. Zeba® seed coating increased seedling shoot DM by 15%. Seeding rates of 11-17 kg ha^-1 resulted in greater seedling shoot DM than seeding rates of 22-34 kg ha^-1. Effects of irrigation on seedling DM were not consistent in both runs of the experiment, most likely because of contrasting precipitation patterns. Aboveground biomass in the first growing season was greater in plants established from coated than non-coated seeds in response to reduced irrigation (Run 1) or irrespective of irrigation (Run 2). In the first growing season, lower seeding rates (11-17 kg ha^-1) resulted in greater aboveground biomass production than higher seeding rates (22-34 kg ha^-1) in response to reduced irrigation during establishment. Full irrigation during establishment resulted in generally greater aboveground biomass production than that in reduced irrigation in the first growing season. Seed coating and seeding rate had no carry-over effects on aboveground biomass production in the second growing season in both runs of the experiment. Plants defoliated at 15 cm height produced more aboveground biomass than plants defoliated at 7.5 cm height. Results suggest that lower seeding rates (up to 17 kg ha^-1) may ensure establishment of ‘Prosper’ tall fescue when soil moisture is less than optimal and increase forage productivity when compared with higher seeding rates. Zeba® seed coating increases seedling establishment under reduced soil moisture.