Australian scientists trick invasive red witchweed into dying

Queensland scientists and Biosecurity Queensland officials are working to eliminate red witchweed, a parasitic plant discovered in Habana, Queensland, in 2013.

The weed attaches to the roots of other plants to steal water and nutrients, which can cause grain and cereal crops to wilt or die. This invasive species has already caused millions of dollars in losses across Africa and the United States. The eradication strategy uses "false host plants" to trick the weed into germinating and then dying.

Michelle Smith, manager of invasive plants at Biosecurity Queensland, explains that soya beans release a chemical into the soil that encourages witchweed seeds to sprout. Because soya beans have a different root structure, the witchweed cannot attach to them and the seedlings quickly perish. Authorities also use soil fumigation and herbicide treatments to manage the infestation. The program has reduced the affected area from 110 hectares to 4.3 hectares over 11 years.

Farmers like Stephen and Neiola Vella provided machinery and labor to support the effort while their land was under quarantine. The federal Department of Agriculture approved a proof-of-freedom plan for the final stage of the project. If no new plants germinate during a three-year surveillance period, Australia will become the first country to successfully eradicate the weed.