‘Cimarron' Switchgrass: A New Cultivar for Bioenergy Feedstock Production.

Switchgrass (Panicum virgatum L.) is a perennial, warm-season grass which has high biomass production potential on marginal land, and is native to and widely distributed in North America.  It was selected in 1991 as the model herbaceous species for cellulosic feedstock production by the DOE Bioenergy Feedstock Development Program. Developing new switchgrass cultivars with significantly greater biomass yields enhances the biological and economic contributions of the species to the emerging biofuel industry. Here we report the release in 2008 of a new lowland ecotype switchgrass cultivar, ‘Cimarron’ by the Oklahoma Agricultural Experiment Station.  Before its release Cimarron was tested as ‘SL 93 2001-1’. Cimarron is a synthetic produced by polycrossing seven elite clonal parent plants selected from breeding populations having undergone two or more cycles of recurrent selection for higher biomass yield.  Biomass yields of Cimarron and standard cultivars were compared in 12 Oklahoma environments (years and locations) in four trials. Biomass yields of Cimarron were consistently numerically higher than Alamo, the best check performer, by 4.2-12.1% in all trials. When analyzed over all environments, Cimarron had a mean annual biomass yield (16.06 tons/ha) 1.12 and 3.17 tons/ha greater (P<0.01) than Alamo (14.94 tons/ha) and Kanlow (12.89 tons/ha), respectively.  Biomass yields of Cimarron, Alamo, and usually Kanlow were substantially and significantly greater than those of upland cultivars. The flowering time of Cimarron is approximately 10 to 14 days later than Kanlow, four weeks later than Blackwell, and similar to Alamo. Cimarron plants produce in excess of 12% more tillers per plant than Alamo and Blackwell, and 25% more than Kanlow. Plants of Cimarron are approximately 12 cm taller than Alamo and Kanlow.  A significant potential use of Cimarron is as a bioenergy feedstock crop in the southern states. Anticipated uses of Cimarron also include the traditional ones for soil conservation, wildlife, and livestock grazing and haying.  Cimarron will be distributed by Johnson Seed Co., Enid, OK.