An African fungus that could help control the aggressive weed Navua sedge in North Queensland has been sent to the UK for further testing.
The smut pathogen, which attacks the Navua sedge's flower, has been found during Queensland Department of Agriculture and Fisheries research trips to Africa.
The research trips, the most recent of which is still underway, have unearthed several possible biocontrol solutions that could be released in Australia to fight the noxious weed, which strangles pastures in wet tropics areas.
Biosecurity Queensland principal entomologist Dr Kunjithapatham Dhileepan has been working with researchers from the National Herbarium of Tanzania, Kenya's East African Herbarium and the University of Southern Queensland to identify possible biological control agents that could tackle Navua sedge, with three different pathogens being considered.
Agriculture minister Mark Furner said during the three-week research trip toTanzania and Kenya Navua sedge flower smut pathogen had been sent to a research facility in the UK for testing, and another two new pathogens were also collected for assessment.
"Navua sedge, which grows in thickets and replaces palatable tropical pasture species, already affects more than 500 beef producers, dairy farmers, crop and hay producers in the Atherton Tableland region alone," he said.
"Identifying these possible biocontrol agents is an exciting development as finding a natural enemy to Navua sedge will significantly help our agriculture industry in the wet tropics."
Mr Furner said the research trip built on previous research trips to East Africa in mid-2018 and West Africa in mid-2019.
"Research conducted on previous trips identified three pathogens with potential as biocontrol agents," Mr Furner said.
"There are now a number of prospective agents that need to be formally identified and checked to ensure that they are not pests on other plants.
"Biocontrol works best with a number of agents attacking different parts or life stages of the target weed and, as some agents might prove to be unsuitable for the task, exploring multiple options to control Navua sedge is crucial to achieving the desired outcome."
Mr Furner said the discoveries had allowed DAF to successfully apply for federal government funding to conduct further tests into the pathogens' suitability to control Navua sedge, although further testing and approvals would be needed before field testing could commence in Queensland.
"Funding through the Agrifutures program means at least one biocontrol agent can now be tested by experts in the UK," he said.
"If proven host specific, applications for release of the particular agents will be submitted to the Australian regulatory authorities for assessment.
"Finding a successful biocontrol option for Navua sedge will provide the agriculture industry with a cost effective and long-term management option to existing mechanical and chemical management options which are expensive and offer only short-term results."