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Four populations of annual sub-tropical weed feathertop Rhodes grass (Chloris virgata) have been confirmed resistant to glyphosate.
Feathertop Rhodes grass has increased its abundance over 10 years largely due to widespread no-till cropping and the shift to glyphosate-based weed control on road verges.
“We have now confirmed that two populations from cropping land in NSW and Queensland and two from roadsides in South Australia are not controlled with glyphosate at the seedling stage and therefore are classified as resistant,” said Australian Glyphosate Sustainability Working Group chairman Chris Preston.
All infestations must be mapped and targeted to prevent spread.