Following detection of an infestation of Noogoora Burr on the DeGrey River, a joint management program was commenced to stop it from spreading.
Noogoora Burr is one of the most serious and widespread weeds in the world. It is poisonous to stock at the seedling stage, and due to the hooked spines on the burr, it is easily transported.
Jo Kuiper, Project Manager at the Pilbara Mesquite Management Committee (PMMC) said there was a multi-organisation on-ground control effort over five days in early July.
Over 400 hours of work was undertaken, coordinated by PMMC with representatives from Main Roads, Department of Primary Industries and Regional Development, weed contractors, the Bettini family, DeGrey Station support crew and PMMC.
Rangelands NRM have been a pivotal supporting organisation of PMMC since its inception in 2001.
Jo said the infestation was very likely to have been introduced from travellers staying at the DeGrey River Bridge camping area.
This is where the largest and densest patches of infestation were recorded.
Noogoora Burr surveillance and or control took place over approximately 40 kms of DeGrey River from approximately 10 km upstream (south) from the highway to 30 kms downstream (north).
“We pulled out and deep-buried the majority of the plants encountered,” Jo said.
“A few patches were chemically treated where it was too extensive and dense to pull out.”
Jo said, unfortunately the burr was mostly in full seed.
“Despite the quickest weed control effort mobilisation possible, the plants have produced seed again this year,” she said.
Based on the surveillance efforts over the last few days, the burr is below detectable levels upstream (south) of the BHP rail bridge and camp/rest area.
However, Jo said they now believe the burr has spread for considerable distances further downstream (past the homestead).
“Fortunately the river has not had major flooding events in the last 2 years, so the burr seed dispersal (mainly by water flow) has been limited to the main river bank along the lower flow lines and does not appear to have been pushed up in to the wider flood plains or flow channels.”
GPS data on the treatment and surveillance efforts were also collected.
Jo said the next task to continue control efforts is to burn the areas where weeds were pulled out in the Highway camping/resting area and the locations where chemical control has been used in an effort to reduce the seed bank left behind.
To progress the development of a medium and longer-term strategy, it has been suggested a round-table meeting would be of great benefit.
“It is not often that so many agencies and groups work in such a collaborative and positive way to achieve no-fuss, on-ground outcomes,” Jo said.
“I sincerely thank everyone for their contributions so far look forward to working with everyone to stop this horrible weed from impacting on our pastoral and biodiversity values.”