Grazing management for the long term utilisation and control of Chilean needle grass ('Nassella neesiana')

Abstract

Chilean needle grass ('Nassella neesiana' (Trin. & Rupr.) Barkworth, CNG) is a tufted perennial that is becoming a serious pasture and environmental weed in south eastern Australia. It is indigenous to South America and was first recorded in Australia in the early 1930s. CND is a perennial stipoid grass found in winter and summer rainfall dominant areas and produces a sharp spear grass type panicle seed, as well as cleistogene seeds within the stems and base of the plant. Once CND becomes reproductive it has limited feed value and the sharp panicle seeds become a grazing welfare risk as they attach readily to livestock and can penetrate their skins and eyes. Stock also become a vector for spreading CNG seed. The distribution of CNG within New South Wales and Victoria has expanded rapidly since the 1990s, replacing desirable pasture species in farmland, and degrading native conservation areas. Many conventional means of control have not been successful in managing CNG. This thesis investigates grazing management strategies in combination with chemical control and pasture rehabilitation for long-term management of CNG.