Primary growth and quality characteristics of Bromus willdenowii and Lolium multiflorum

Prairie grass (Bromus willdenowii Kunth) and a tetraploid Westerwolds ryegrass (Lolium multiflorum Lam.) were established in a field trial in April 1987 and grown for a 3‐month period of undisturbed growth. During this period the biomass partitioning and forage quality of each plant component was compared for the two species. Leaf, tiller and plant populations were assessed on ten occasions while accumulation of herbage and roots, chemical composition, leaf area and light interception were determined on six occasions. Herbage was divided into leaf lamina, inflorescence, vegetative and reproductive pseudostem. Nitrogen, water‐soluble carbohydrates, ash, cell wall and in vitro digestibilities were determined. Prairie grass had lower plant, tiller and leaf populations but larger tillers and more live leaves per tiller than Westerwolds ryegrass. Both species had similar light interception and leaf area index. Roots were distributed more evenly and to greater soil depths in prairie grass. Leaf lamina made major contributions to herbage DM accumulation and accumulation of the various chemical components, but as reproductive development occurred, reproductive pseudostem became a major component of the total sward. Harvesting herbage to gain optimum quantities of DM, herbage quality and regrowth is discussed. It is concluded that prairie grass is a high‐yielding, high‐quality forage grass, comparable with Westerworlds ryegrass.