Effects of winter cutting management on growth and tiller numbers of six grass species

Abstract

Abstract Tiller numbers of six grass species grown with ‘Grasslands Huia’ white clover (Trifolium repens L.) increased from early winter 1982 to mid winter, with a small reduction in late winter. Tiller numbers almost doubled in ‘Grasslands Roa’ tall fescue (Festuca arundinacea Schreb.) and ‘Grasslands Maru’ phalaris (Phalaris aquatica L.). Cutting three times in winter gave higher tiller numbers in late August than cutting twice. Maru, Roa, and ‘Grasslands Matua’ prairie grass (Bromus willdenowii Kunth) had the highest winter growth rates; 17, 12, and 13 kg DM/ha per day respectively. ‘Grasslands Nui’ perennial ryegrass (Lolium perenne L.), ‘Grasslands Kahu’ timothy (Phleum pratense L.), and ‘Grasslands Wana’ cocksfoot (Dactylis glomerata L.) had low winter growth rates (< 10 kg DM/ha per day). Kahu had the highest growth in early spring, Matua the slowest. Plots cut twice in winter grew more during winter than plots cut three times, but the reverse occurred in early spring: the possible implications of this in ‘all-grass wintering’ are discussed. In a second trial with pure stands of Nui and Matua only, cutting to 2 cm height gave higher yields than cutting to 4 cm in winter, but the reverse occurred in early spring. Matua outyielded Nui in winter but yields were similar in early spring. Matua also had a higher nitrogen (N) content. Tiller numbers remained unchanged at the three counting dates, possibly a result of a soil N shortage in winter.