RIPGUT BROME (BROMUS DIANDRUS) DISTRIBUTION IN RELATION TO TOPOGRAPHY AND MANAGEMENT ON SEVEN HIGH COUNTRY PROPERTIES IN THE SOUTH ISLAND

摘要

Seeds of ripgut brome, an annual grass, can contaminate the wool, pelt and carcasses of sheep grazing on high country properties. The distribution of ripgut brome on seven high country properties in Marlborough, Canterbury and Otago was determined during December 2006 to February 2007. The presence of ripgut brome was measured in paddocks of different management intensities at altitudes ranging from 400 to 1400 m. Ripgut brome grass presence was lower in sites managed less intensively (e.g. less fertiliser and oversowing), in hard than laxly grazed sites, and in sites of high exotic perennial grass cover. It was more prevalent on stock camps than off stock camps and on steeper slopes and sunny aspects but was unaffected by legume cover, shrub presence or altitude. The results suggest that increased grazing intensity and enhanced plant competition are methods that may be used to suppress ripgut brome on hill and high country properties.