Rogue stinknet weed infestation squashed near Orroroo
The eagle eyes of a Northern and Yorke Landscape Board officer has stopped a weed never seen before in South Australia in it tracks.
Landscape officer Nick Modra spied the stinknet or globe chamomile weed (Oncosiphon piluliferum) on a roadside about 10km south of Orroroo in late 2022.
The weed had overtaken a 100 metre stretch of the roadside and its bright, yellow flowers and strong resemblance to the declared weed calomba daisy caught Nick’s eye.
“Even from a distance, it was clear that it wasn’t one of our many native daisies with yellow flowers, like a billy button, so I quickly took a sample, snapped some photos and consulted with a couple of plant gurus in our team,” said Nick.
“This patch of stinknet is the first known infestation within South Australia, with all other recent records found between Perth and Kalgoorlie, indicating that it had likely hitched a ride across the Nullarbor.
“Its closest relative calomba daisy invades grazed pastures and native vegetation and stinknet has the ability to do the same. It’s a significant problem weed in Arizona and California, where it has invaded roadsides and open fields, creating an increased fire danger and displacing native plants.”
Due to early identification, Nick believes it’s feasible to eradicate this infestation. This summer’s early rains triggered multiple germinations, so he treated the area five times to prevent any seed set.
“Because we detected this weed soon after its arrival, we have an excellent opportunity to eradicate it. The first two years of treatment have already seen a big reduction in its density, and we just need to make sure it doesn’t spread to other areas,” he said.
The Northern and Yorke Landscape Board encourages landholders and community members to notify its team about unusual plants in the landscape. Take a photo of the plant and send it to your local landscape officer for identification.
“We’re always happy to be plant detectives, as it allows us to intervene with new plant infestations at an earlier stage, greatly increasing the chances of success,” said Nick.
Contact the Northern and Yorke Landscape Board on (08) 8841 3444 or find out about weeds in our region.
