FORAGE QUALITY OF 5 COOL-SEASON GRASSES .1. CULTIVAR EFFECTS

A field experiment was conducted over 2 years to evaluate five cultivars and four experimental synthetics of smooth bromegrass (Bromus inermis Leyss.), six cultivars of orchardgrass (Dactylis glomerata L.), four cultivars of timothy (Phleum pratense L.), three cultivars of tall fescue (Festuca arundinacea Schreb.) and two cultivars of reed canarygrass (Phalaris arundinacea L.). Herbage was sampled on seven dates during spring and early summer. Each treatment was replicated three times. Cultivars differed in nitrogen (N) concentration for orchardgrass, timothy and tall fescue. Timothy cultivars varied most in N, ranging from 24.7 g kg-7 for 'Clair' to 27.2 g kg-1 for 'Verdant'. Within each species, the later maturing cultivars were generally highest in N. Cultivar differences in in vitro dry matter disappearance (IVDMD) were found for smooth bromegrass (range 41 g kg-1), orchardgrass (range 22 g kg-1) and timothy (range 27 g kg-1), but not for the other species. Cultivar effects for neutral detergent fiber were significant only for smooth bromegrass (range 27 g kg-1) which also differed in acid detergent fiber and hemicellulose. Cultivars of reed canarygrass, orchardgrass and timothy differed in cellulose, hemicellulose and acid-insoluble ash, respectively. Cultivar × date interactions were generally not significant except in 1982 when all species but orchardgrass had interaction effects for one or more constituents. These data indicate that grass cultivars differ in quality but that, within a species, cultivars generally respond similarly to advancing maturity. © 1990.