Effect of Cutting on Production and Tillering in Prairie Grass (Bromus willdenowii Kunth) Compared With Two Ryegrass (Lolium) species. 2. Reproductive Plants

Effects of time of initial cut and subsequent cutting interval (1, 2 or 4 weeks) were examined in a glasshouse during summer 1988 for reproductive plants of three prairie grass cultivars (Bromus willdenowii Kunth), Westerwolds ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (Lolium perenne L.). Measurements were made of tiller and leaf numbers, sites of tillering, reproductive development, and herbage quality and yields. Effect of time of initial cutting on regrowth appeared to be independent of stage of reproductive development and unrelated to any of the measured plant parameters. Characteristics for each cultivar as identified during undisturbed growth prior to the initial cuts, were modified by the subsequent cutting frequencies. Perennial ryegrass had the highest yields under frequent cutting with high herbage quality. Westenwolds ryegrass and the prairie grass cultivars ‘Grasslands Matua’ and ‘Primabel’ had the highest yields with infrequent cutting, but lower herbage quality than in perennial ryegrass. At each cut, tiller death in prairie grass was determined by the number of reproductive tillers, and in the ryegrasses also by the numbers of elongated vegetative tillers. Recovery of tiller numbers was rapid and primarily from inhibited tiller buds at the base of reproductive tillers. In prairie grass, tiller numbers were relatively unaffected by cutting frequency, but at frequent cutting, many axillary tillers originated from vegetative tillers rather than from inhibited tiller buds at the base of reproductive tillers.