Arrhenatherum elatius (L.) Beauv. - a review, and evaluation of tall oat grass for dryland and hawkweed-affected country in the South Island

Abstract

Tall oat grass has a long history in New Zealand agriculture. Reference was made to it in the 1880s as a useful grass and it was included in many trials such as those of Macpherson, Cockayne, Calder, Dunbar, Sievwright, Moore and others. While the survival and performance of tall oat grass was generally reported as being good, observations on palatability were mixed. The growth pattern was typically noted as being one of early spring growth, rapidly changing to reproductive form thereafter with a consequent decrease in acceptability to stock. In 1988, new accessions of tall oat grass originating from diverse countries were introduced to New Zealand from the US Department of Agriculture. This paper describes the physical characteristics of tall oat grass and field performance at Galloway Station, a site badly affected by hawkweed, and on other farms. This grass appears best suited to moderate-low rainfall areas (400-700 mm p.a.) which are not too exposed or too cold and it shows good potential for survival and spread in the drier soil conditions which result from hawkweed invasion in mid-altitude grassland areas. Two accessions, one from Chile and the other from Switzerland, have been identified which have superior winter performance, rust resistance and are less prone to bolting into a reproductive phase in the spring. These, along with a preliminary selection containing a wider genetic base, are being commercially evaluated at present. Keywords: Arrhenatherum elatius, tall oat grass, hawkweeds, plant selection, vegetation