25 January 2021.

Dense Gamba grass

CSIRO is leading the way when it comes to gamba grass - a controversial pasture weed that’s great for hay production and grazing but when left unutilised increases the risk of devastating wildfires. 

The organisation is working on the development of biocontrol options, such as fungal pathogens, worms, and an insect stem borer, to be introduced to reduce the plant’s spread. This is in addition to existing chemical control and regulations.

Now AgForce is being urged to support CSIRO’s biocontrol nomination to the Environment and Invasives Committee (EIC) and members are being called on for their viewpoint.

Initially introduced to Australia as an improved pasture for graziers, gamba grass has since become a significant environmental weed, which has led to it being declared noxious by all jurisdictions where it’s found.

This includes 1 to 1.5 million hectares in Queensland (particularly Cape York and in the Mareeba Area) and the Northern Territory, as well as smaller populations in the east Kimberly Region of Western Australia.

Gamba outcompetes native grasses for resources and because it grows up to four metres tall is highly combustible during late dry season - resulting in fire intensities eight times greater than regular grass fires and costing the economy 26 times more.

But gamba grass also has its benefits. It is extremely hardy in tropical climates and can even survive infertile soils, which means it can carry 40 times more cattle than native pastures.

CSIRO’s proposed biocontrol agents may damage gamba grass enough to reduce wildfire risk and spread, while leaving the forage value of gamba unaffected.

AgForce has been asked to write a letter of support for CSIRO’s proposed biocontrol program, so it’s time to have your say – is gamba grass your friend or foe?

Please contact AgForce Policy Officer Marie Vitelli on 07 3236 3100, mobile 0429 062 852, or email