Five weeds, five districts and one wet season
Priority roadside weeds have been treated in five of the board’s districts.
The control work targeted infestations of Buffel grass (Cenchrus pennisetiformis), Calomba daisy (Oncosiphon suffruticosum), African Rue (Peganum harmala), Prickly pear (Opuntia stricta) and Wheel cactus (Opuntia robusta).
The work across the SAAL region was undertaken in the Kingoonya, Gawler Ranges, North Flinders, Port Augusta-Quorn and North East Pastoral regions. It was partly funded by the Department of Infrastructure and Transport (DIT), which also provided funding for additional roadside weed control in the Eyre Peninsula and Northern and Yorke Landscape regions.
Buffel grass, African Rue and all Opuntia cacti species are declared weeds in South Australia. Opuntia cactus species are also weeds of National Significance (WoNS). All come with different responsibilities for landholders, but all have restrictions on movement and an expectation for control.
While not a declared weed, landowners are expected to take reasonable steps to kill infestations of Calomba Daisy and prevent its spread.
Buffel grass in the Port Augusta-Quorn region was initially sprayed with Pine Oil and cut back to allow for control of newly emerging plants. After rain, the control was far more widespread. Actively growing plants were sprayed with a mixture of residual herbicide (Fluproponate), knockdown herbicide (Glyphosate) and seed suppressant (Pine Oil). This work was undertaken in 13 different locations in the North Flinders, Port Augusta Quorn, Gawler Ranges and Kingoonya districts.
An alternative herbicide (Haloxiflop) was trialled on a large infestation in the Port Augusta-Quorn district.
The unprecedented high rainfall experienced across the region meant most Buffel grass infestations had significant regrowth and were treated multiple times.
An emerging weed in the Kingoonya district, a small infestation of Calomba daisy on the Stuart Highway was treated with Metsulfuron-methyl, while Glyphosate was used to treat an African Rue (Peganum harmala) infestation on Flinders Ranges Way and Opuntia species on the Barrier Highway.
DIT has provided additional funding to continue support of this work in the SAAL region during the 2026/27 financial year.
