Dr Chris Preston and Dr Peter Boutsalis, researchers from the CRC for Australian Weed Management (Weeds CRC), the University of Adelaide and national Glyphosate Sustainability Working Group (GSWG) today confirmed that a population of liverseed grass (Urochloa panicoides) from summer fallows in New South Wales has become resistant to glyphosate (eg Roundup), the most valuable herbicide in Australian agricultural systems. The announcement comes only a year after glyphosate resistance was confirmed in northern New South Wales in two populations of awnless barnyard grass (Echinochloa colona), and twelve years after the first case of glyphosate resistance was recorded in a population of annual ryegrass (Lolium rigidum) near Echuca, Victoria.