Hopes are high as a research project into a leaf smut fungus that combats giant rat's tail grass winds up this week.
It has been revealed native and introduced pathogens of GRT have been part of a Department of Agriculture and Fisheries project, following a Question on Notice by member for Burnett Stephen Bennett about the shortage of the chemical flupropanate used to spray GRT.
DAF have been conducting research and field experiments to determine the impact of a recently discovered GRT leaf smut, with results to be published after conclusion of the project at the end of March.
Mr Bennett described the response as a "light at the end of the tunnel" for local producers battling the weed, with two species of stem feeding wasps, found to be host specific to GRT in South Africa, also mentioned as being under scientific research.
"Local graziers and producers have been waging war with the weed for decades," he said.
"Cattle can't eat it and chemicals are needed to control it.
"The pest weed has been besieging landowners like never before due to a shortage of the best poison to control it - flupropanate, but there could be hope on the horizon in the form of wasps and smut."
"I can now confirm that the field experiments and research to determine the impact of the recently discovered GRT leaf smut is well underway," he said.
"While the results are yet to come, we're hearing it could lead to the release of at least one suitable native pathogen for the biological control of GRT.
"The project is looking at the development of rearing methods for the identified pathogens and conducting testing on the pathogen species, and is due to come to an end this month with a final report to follow."
But landowners between Bundaberg and Gladstone believe the GRT devastating leaf smut has already arrived and is making a big impact on the weed.
DAF has confirmed Biosecurity Queensland has established a trial site at Miriam Vale in the region to demonstrate GRT management.
Avondale macadamia grower John Brand heard rumours from other producers that GRT was suffering in the region and was excited by the news.
"In the past, there's really been no way of stopping giant rat's tail grass," he said.
"Spray, slash, repeat, spray, slash, repeat, you do everything possible, but it inevitably it will keep coming back.
"So when I heard rumours of this pathogen effectively controlling the rat's tail in the area, you bet I was excited."
ALSO IN THE NEWS:
Mr Brand then noticed the impact on his own property.
"I first discovered what appeared to be weakened rat's tail on our property about six-months ago," he said.
"As the season progressed, I noticed the emerging rats tail had either weakened seed head or no seed head at all and also noticed brown centres in the plants and red rusty spots with black dots on the leaves.
"We had one particular block that we thought we'd lost control of, today it seems to have almost no rats tail at all and the signal grass has taken over."
Mr Brand said he hoped this could mean a shift in the war against the pest that was first introduced to Australia in the 1960s and is now found from northern Cape York to the New South Wales central coast.
"I believe we'll continue to see rats' tail grass emerge over the next few years due to the existing seedbank in the soil, but it'll certainly become much less prevalent," he said.
"We've been keeping a keen eye on the pathogen and to date, I haven't seen it effecting any other grasses.
"This could be a game changer for growers and graziers."
North of Mr Brand, Brahman cattle grazier Noel Gaston at Hazelwood, Lowmead, lost the war against GRT and more than three years ago stopped spraying as the seed count on the ground was too high.
But he has just noticed a change with the GRT showing the signs of stress from what he believes is smut fungus.
"I gave up spraying, it was a waste of money," he said.
"I was told there was too much seed in the ground to stop it, but about three years ago I noticed an easement where it was dying.
"Now after the wet conditions we have it seems to be destructively impacting in a lot more places."
He is hoping now he will see it firmly take hold on the invasive weed and dramatically reduce its numbers or even kill it off as the rain moves on.
"I think this should all die," he said.
"I have seen patches die, so I expect now the rain has stopped it will start to die off."
Agforce senior policy officer Marie Vitelli said GRT leaf smut was active in the region and it could be helpful in reducing the weed's yield but was not a magic solution.
"Giant rat's tail grass control is enhanced at locations where the GRT leaf smut is active," she said.
"The fungal leaf smut reduces vigour and seeding of weedy GRT grass.
"Prevalence of GRT leaf smut can be patchy and sporadic, so it is not the only tool required for effectively managing GRT."
The DAF leaf smut project is coming to an end in March 2023 and a final report will follow.
