Nutritive Value of Virginia Wildrye, a Cool‐Season Grass Native to the Northeast USA

blue wildrye (E. glaucus Buckley), and Dahurian wildrye (E. dahuricus Turcz ex Greiseb) the most noteworthy Interest in native plant species for conservation and production of the Elymus wildryes as forages and briefly mentioned has increased because of new federal policies. We evaluated accessions of the native cool-season grass Virginia wildrye (Elymus virginicus Virginia wildrye for revegetating prairie (Asay and JenL.) from the northeastern USA for nutritive value and its association sen, 1996). Closely related, both Virginia wildrye and with plant morphological traits. Thirteen accessions, one cultivar Canada wildrye are highly self-fertile allotetraploids (Omaha), and one commercial ecotype of Elymus were transplanted (2n 28) with the SSHH genome constitution (Asay into single-row field plots in late summer of 2000 at Beltsville, MD, and Jensen, 1996). Very little breeding has been done Rock Springs, PA, and Big Flats, NY. Two orchardgrass (Dactylis in either species. In an evaluation of 30 grass species in glomerata L.) cultivars were included. Primary growth was harvested Saskatchewan, Canada, Virginia wildrye was considered in April (Beltsville) or May (Rock Springs and Big Flats) of 2001 and a promising forage grass, but lack of winter hardiness 2002 and analyzed for neutral detergent fiber (NDF), crude protein limited its persistence (Lawrence, 1978). Hereafter in (CP), and digestible NDF (dNDF). Nutritive value measures were this paper, the terms “Elymus” and “wildrye” will refer related to plant morphological attributes [leaf width, length, area, and leaf-to-stem mass ratio (LSR)]. Virginia wildrye accessions difto E. virginicus. fered (P 0.01) in nutritive value and often had lower NDF and Genetic variation for nutritive value occurs within higher CP and dNDF than the commercial ecotype, Omaha cultivar, many species of cool-season introduced grasses (Casler and orchardgrass. The LSR accounted for most of the variation in et al., 1996). Sometimes the variation in nutritive value nutritive value. Orchardgrass was more mature at harvest than Elymus results simply from differences in maturity or plant morentries and thus lower in nutritive value. Neutral detergent fiber was phology. For example, the LSR of grasses typically denegatively correlated with LSR (r 0.26 to 0.74, P 0.05), clines with maturity and is accompanied by a decrease whereas CP and dNDF were positively correlated (r 0.36 to 0.80 in nutritive value (Nelson and Moser, 1994). Nutritive for CP and 0.44 to 0.74 for dNDF, P 0.05). Neutral detergent fiber value of grasses, however, can be improved by changing was also positively correlated (r 0.27 to 0.86, P 0.05) with leaf the cell wall composition without affecting plant matulength. Virginia wildrye is comparable to other cool-season grasses in nutritive value. rity or gross morphology [e.g., in smooth bromegrass (Bromus inermis Leyss); Casler and Carpenter, 1989]. Plant morphology can influence other traits related to livestock performance. For example, leaf width in tall M forage grasses grown in the northeastern fescue was negatively related to leaf tensile strength USA are introduced species such as orchardgrass, and, hence, positively related to preference by grazing bluegrass (Poa spp.), or tall fescue (Festuca arundinacea cattle (MacAdam and Mayland, 2003). Schreb.). Native warm-season perennials, such as switchGreater interest in the use of native grass species in grass (Panicum virgatum L.) and big bluestem (Androconservation and other plantings has created a need for pogon gerardii Vitman), account for most of the native more information on the suitability of locally adapted grasses used in forage systems. Few, if any, native coolnative species for the northeastern USA. We could not season grasses have been evaluated as potential forage find any information on the nutritive value of Elymus species in the northeastern USA. New federal policies as a forage grass in the northeastern USA. Previously, related to invasive species, conservation plantings, and we reported on the productivity, morphology, and perfarm programs have created greater interest in native sistence of several Elymus accessions at three locations plants for conservation and production during recent in the northeastern USA (Sanderson et al., 2004). Our years (Richards et al., 1998; Federal Register, 1999). objective in this study was to evaluate the same northVirginia wildrye, a perennial cool-season grass native eastern accessions of Virginia wildrye for nutritive value. to the northeastern USA, grows along streams, forest margins, and in other moist areas (Pohl, 1947; HitchMATERIALS AND METHODS cock, 1971). It is recommended as a component in some conservation plantings for revegetation. Asay and JenThe experiment was conducted at the USDA-NRCS Plant sen (1996) considered Canada wildrye (E. canadensis L.), Materials Center in Big Flats, NY (42 N, 76 54 W, elevation 290 m), the Russell E. Larson Agricultural Research Center at Rock Springs, PA (40 48 N, 77 52 W, elevation 365 m), Matt A. Sanderson and R. Howard Skinner, USDA-ARS Pasture and the USDA-NRCS National Plant Materials Center in Systems and Watershed Management Research Unit, Bldg 3702, CurBeltsville, MD (39 02 N, 76 56 W, elevation 36 m) during 2000 tin Road, University Park, PA 16802-3702; Jennifer Kujawski, USDAto 2002. Soil types were Unadilla silt loam (coarse-silty, mixed, NRCS National Plant Materials Center, Beltsville, MD 20705; Martin van der Grinten, USDA-NRCS Plant Materials Center, Big Flats, NY active, mesic Typic Dystrudepts) at Big Flats, Hagerstown silt 14830. Received 5 December 2003. *Corresponding author (mas44@ psu.edu). Abbreviations: ADF, acid detergent fiber; CP, crude protein; dNDF, digestible neutral detergent fiber; IVTD, in vitro true digestibility; Published in Crop Sci. 44:1385–1390 (2004). Crop Science Society of America LSR, leaf-to-stem mass ratio; NDF, neutral detergent fiber; SLA, specific leaf area. 677 S. Segoe Rd., Madison, WI 53711 USA