Australia restricts paraquat application rates by 80 per cent

The Australian Pesticides and Veterinary Medicines Authority (APVMA) has implemented significant restrictions on the herbicide paraquat, reducing the allowable application rate by 80 per cent. Following a safety review, the maximum rate has dropped from 1150g/ha to 231g/ha.

Professor Bhagirath Chauhan of the Grains Research and Development Corporation (GRDC) Weed Management Initiative warns that these changes will increase the risk of herbicide resistance for Australian grain growers. He noted that the new, lower application rate is less effective on weeds larger than four centimetres in diameter or grasses past the four-leaf stage.

Previously, paraquat was a vital component of ‘double knock’ strategies used to minimize glyphosate resistance. Experts suggest that while the restrictions present a management challenge, growers may be able to control problem weeds through a combination of alternative techniques.