Graziers and scientists have united to discuss managing pasture dieback in a Queensland research trial site.
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The Applied Horticultural Research site is one of four established in the state to find ways graziers can produce feed in paddocks that have been severely affected by pasture dieback.
With pasture dieback mealybugs now understood to be the main cause of the issue, QUT associate professor Caroline Hauxwell said the focus of farmers and researchers could move to managing the devastating and costly issue.
"If you know what is causing this you can manage it, it's not the bogeyman," she said.
"We know it is a mealybug that is causing this problem, it isn't going away and it hasn't gone away in 10 years, it is settled in, establishing and heading south into New South Wales and it can travel long distances on wind."
Ms Hauxwell said the mealybug is a new variant and believes it most likely is an incursion, carried by wind from overseas or accidentally transported into the country.
And while the dieback was only first recorded on scale in 2011, she believes the pest would have been in Australia "longer than that."
Use it or lose it
Spotting dieback early was one of the vital tools in management Ms Hauxwell said, with the juvenile insects causing the damage feeding through spring and summer before the adult females disperse and hide, with some travelling deep underground until the fresh grass returns and they lay their eggs.
"We know the mealybugs by feeding on the plant are causing the immune system to shut down," she said.
"It takes very few mealy bugs to do that and they do it very quickly, so if you can get that population down, the grass can recover.
"The first thing is if you see them in that spring early summer period, graze the grass, bale it if possible or as a very last resort slash it - but crash grazing seems to work really well, it stops them from breeding.
Pasture variety vital
Combating the pasture dieback mealybug long term is also important for graziers Ms Hauxwell said, and that comes down to sowing crops not susceptible to the insect.
Dr Noami Diplock is a plant pathologist passionate about helping to solve the issue of pasture dieback and in the research trial has concentrated the cultivation of 14 varieties of grasses as well as legumes in the impacted Gaeta paddock to discover fodder that may be dieback resistant.
"Biodiversity of grasses plus a legume mix seems to be the key," she said.
"If you have been impacted, resow with pasture that suits your conditions as well as a good mix of legumes amongst there and that will reduce dieback.
"Use tolerant grass species, and in these trials Mekong Briz antha is a standout, Tully grass is also doing well, some of the Rhodes grasses are holding up well across all sites and Gatton panic is fantastic, especially when mixed with legumes."
Dr Diplock, who has won awards for her work dealing with dieback, agreed controlling the mealybug could not be achieved but planning pasture could help manage the impacts.
"We need to be able to manage our pastures and produce feed with mealybug there," she said.
"It really depends on each persons situation, if you have high weed pressure it might not be possible to increase legumes in your paddock because if you need to spray you will lose your legumes, but by increasing your grass mix you are still going to face less dieback.
"But if you can introduce legumes, which aren't impacted, you are also going to get less dieback."
Landowner Chris Roffey has hosted the pasture dieback trial since 2021 after concerns of the impact to his cattle property.
"We could see it was going to be an absolute disaster if something didn't happen in the way of control of management and want to see the possibilities," he said.
"The Mekong biz is doing very well, the cattle broke in here this morning and it's the only one they chewed on and that's good because I had hesitations about it being palatable and I do still have hesitations about its dominance in pastures."
Mr Roffey said he was still extremely concerned about dieback and how it was impacting production but was thankful some solutions are coming forward.
"I feel a hell of a lot better than I did two years ago when there was nothing on the horizon," he said.
"Our dominate grass is creeping bluegrass and that is one of the grasses dieback just loves.
"We have tried to create some diversity in the past but the bluegrass is so dominate it choked it out, but we are aiming to run a place with a mixture."
Mt Perry grazier Russel Augustine attended the information session at the trail site seeking answers to the problem after discovering mealybugs at his property.
"We have a bit of country with dieback and have for a few years," he said.
"We found a fair few mealybugs under the microscope so that proved that was them in ours.
"I'm just looking for as much knowledge as possible."
The pasture dieback trails will continue with more solutions being released later this year.
