Council trial successfully weeds out giant pest

A 12-month trial program using a variety of control techniques run by Sunshine Coast Council to combat the highly-invasive Giant rat’s tail grass (GRT) has shown remarkable results and will now be rolled out across council-managed road reserves.

Listed as a restricted invasive plant under the Biosecurity Act 2014, GRT is an aggressive weed that reduces pasture productivity and can significantly degrade natural eco-systems.

Environment Portfolio Councillor Jenny McKay said GRT was a huge concern for council and our rural landholders.

“GRT is a fast spreading weed that can significantly reduce pasture grasses for livestock, making it a serious issue for our local farmers,” Cr McKay said.

“Council conducted a six-month field trial in 2015 that showed positive results, so this extended trial was designed to validate the longer term success of the control methods.

“The trial aimed to make a significant reduction in the presence of GRT and involved testing new methods to destroy existing plants and also reduce the spread.”

The trial involved:

• Herbicide applications across infested land
• Council’s free weed control hire equipment offered to property owners for use in the project area
• Infested areas were not to be slashed during the treatment period to remove any risk of weed seed spread and to maximise the uptake of applied herbicides
• Non-chemical trial plots - infested areas were brush cut to remove all viable seed heads and geofabric was installed over the infestation
• Data collation post spring and summer treatments.

The program was held over multiple land tenures at two rural locations, Belli Park and Kidaman Creek to coordinate control efforts across private property, state and local government lands.

The Belli Park trial results showed a reduction in unique locations along the public road reserves from 11 to 1, with an overall reduction on council and Department of Transport and Main Roads (DTMR) road reserves of 82 percent and 92 percent respectively.

At Kidaman Creek, there was a reduction in unique locations along the public road reserves from 8 to 1, with an average overall reduction on council and DTMR road reserves at 100 percent and 81 percent respectively.

The results were particularly encouraging at the non-chemical geofabric control site where a 100 percent reduction was achieved. This location will continue to be monitored for the next one to two years to assess the ongoing success.

Cr McKay said it became apparent during the trial that a chemical and non-chemical approach would be beneficial in the management of Giant rat’s tail grass.

“The trial identified enhanced treatment options that will also reduce the cost of combatting this invasive plant,” Cr McKay said.

“All areas of council road reserve and DTMR sites with GRT issues will now be managed using this best-practice combination of scheduled herbicide treatment and geofabric weed matting.”

Other program outcomes included data sharing of infestations with relevant authorities to minimise the risk of rural slashing operations and roadside works contaminating equipment and further spreading GRT weed seed along road corridors; increasing public awareness through the installation of signage where weed matting locations are installed; priority for council’s free weed control hire equipment to be given to property owners with GRT issues who are undertaking best practice management strategies.

Find out more about invasive plant management.