Australia is on track to become the first country to eliminate a weed that causes million-dollar losses of grain and cereal crops in Africa and the US.
Red witchweed was discovered in the sugarcane farming community of Habana, north of Mackay in Queensland, in 2013.
Surveillance will continue to check if new seeds germinate.
A highly invasive weed discovered in north Queensland has been tricked into triggering its own death.
Red witchweed was found on six sugarcane farms in Habana, north of Mackay, in 2013, the only known detection in Australia.
Scientists say a clever biosecurity strategy of planting "false host plants" has played a significant role in the eradication strategy.
Red witchweed is a parasitic plant. To survive, it must attach itself to the roots of another plant to steal water and nutrients, eventually starving its host.
Michelle Smith, manager of invasive plants at Biosecurity Queensland, said soya beans release a natural chemical into the soil which stimulates witchweed seeds to germinate.
Soya beans have a different root structure, which makes them an incompatible host for red witchweed.
"Without a host connection, the seedlings quickly die," Ms Smith said.
Soil fumigation and herbicide treatments have also been used with success.
Ms Smith said the weed could wipe out grain and cereal crops and had caused multi-million-dollar losses in Africa…
