Ryegrass resistance to paraquat in Australia
Australian researchers have identified the first cases of resistance to the non-selective herbicide, paraquat, in annual ryegrass (Lolium rigidum). The scientists from the University of Adelaide’s Waite Research Institute found resistant ryegrass populations on two farms in South Australia. The development is a concern because paraquat is the only knock-down herbicide apart from glyphosate that can be used to control the weed, the researchers point out. Over 100 ryegrass populations in Australia have developed resistance to glyphosate.