Rangelands NRM Blog, News & Resources

New weed control methods in Pilbara proving a success

Considerable progress has been made in the Pilbara over the past two years to tackle Mesquite and Parkinsonia, both Weeds of National Significance (WoNS).

With funding from both Rangelands NRM and the State NRM Office, the Pilbara Mesquite Management Committee (PMMC) have been focusing work on-ground and with pastoral stations in the region.

Rangelands NRM have provided funds to coordinate and develop the program. This has included setting up monitoring sites, mapping and data collection.

Project Manager Linda Anderson said the State NRM Office has provided funds to purchase herbicide and employ contractors or station staff to go out and undertake on-ground control.

“We have provided training, provided the equipment and demonstrated how to control the weeds,” Ms Anderson said. “Then they take the knowledge out and put it into practice.”

A demonstration site for the mechanical control of mesquite was set up in the past year. Both types of mesquite – the treeform type as well as the hybrid species – were treated and medium to dense infestations were knocked out.

The mechanical control method involves a blade mounted on the front of a dozer. The dozer pushes the plant over and then the bar cuts the plants up underneath and severe off the roots. The trees are collected, piled up and we will look at burning them to get rid of stemming matter and reduce the risk during floods or mustering.

Ms Anderson said mechanical control was effective with both types of mesquite and proved to be cost effective and time effective. It also allows access in to control regrowth in follow up years.

“Mechanical control with treeform mesquite near Onslow was trialled and early results indicate it’s a really good tool,” she said.

Part of the training involves showing people how the control work undertake is monitored.

“Handheld GPS with dataloggers are used to record where people have been and where weeds have been controlled,” Ms Anderson said.

“It’s a requirement for anybody who wants assistance with their weed control activities. We can then see where is clean or where more control is needed.”

There are five different categories of plants that can be recorded: single plants, lots of ten plants, lots of 100 plants, seedlings (masses), and whether it is mesquite or parkinsonia.

Ms Anderson added that the release of Leaf Lying Moth in 2000 has resulted in de-foliation of these weed species. “While this doesn’t actually kill the weeds, it has a big impact on stopping their spread.”

Ms Anderson said similar type work has been done with the Parkinsonia in the region. Alongside the mechanical control, chemical treatment is primarily used with herbicide mixed with diesel.

“Specific methods are needed on how to treat these weeds or else the tree will grow back. When done properly its really effective.”

“We are getting fantastic maps coming back showing really excellent coverage and plants we would have never found if they hadn’t been gridding out areas.”

The PMMC is launching their new website at the end of February which can be visited at:

For more information, contact Project Manager Linda Anderson by email.