Registration of ‘Dawn’ Orchardgrass

'Dawn' orchardgrass (Dactylis glomerata L.) (Reg. no. CV-13, P1 566817) was developed by Land CPLakes, Inc., Webster City, IA, and released for marketing through Research Seeds, Inc., St. Joseph, MO, in 1989. Dawn was tested under the experimental designation DS7. It is a hardy, medium-maturity, eight-clone synthetic cultivar. Unlike the parentage of most cultivars currently available in the USA, five of the eight parental clones are selections from plant introductions (P1) of recent origin from the former USSR. Parents were derived from P1 315425 (three clones), P1 325302 (one clone), and P1 315417 (one clone). The other three parental clones were derived from 'Jackson'. Selection of parent clones was based on clonal and polycross progeny evaluation for seed and forage yield, stem and crown rust and leaf scorch resistance, and late maturity over several years at Webster City, IA, and for seed yield at Caldwell, ID. Dawn averaged 3 to 4 d later for heading and anthesis date than 'Potomac', 'Sterling', and 'Hallmark' in the midwestern USA and 12 to 17 d later in the Willamette Valley of Oregon. It has exhibited greater winter hardiness and greater resistance to stem and crown rust (caused by Puccinia graminis Pers.: Pers. and P. coronata Corda, respectively) than Potomac, Sterling, Hallmark, and 'Pennlate' in Iowa and Wisconsin tests. Dawn is moderately resistant to leaf scorch [caused by Cercosporidium graminis (Fuckel) Deighton]. It had shown 1 to 3% higher digestibility than Sterling and Hallmark in Iowa State University trials. Forage and seed yields were similar to Potomac, Sterling, and Hallmark in the Midwest USA. Under adequate moisture conditions in the Willamette Valley of Oregon, seed yields of Dawn were similar to Potomac, Sterling, and Hallmark. Dawn is adapted for forage and conservation use in the northern half of the USA and in southern Canada in areas where orchardgrass is commonly grown. Breeder Seed I was produced on replicated ramets of the parental clones in isolation at Webster City, IA, by Land O'Lakes, Inc. Breeder Seed U was produced at the same location on an isolated seeding of Breeder Seed I and was limited to 2 yr of seed increase. Breeder Seed I and n are maintained by Forage Genetics, West Salem, WI. Foundation seed fields are planted with Breeder Seed I or II in Iowa and the Willamette Valley of Oregon, with a limit of three harvest years. Certified seed fields are planted only in the northern USA. Only one generation of foundation and certified seed production is permitted. Dawn was accepted by the Grass Variety Review Board in April 1988. United States Plant Variety Protection was not applied for. It has been licensed and registered in Canada as 'DS7' (Agriculture Canada Reg. no. 3631).