Dealing with weeds
Grassroots research is raising hope – ground can be reclaimed from one of Australia’s most invasive and destructive weeds.
While they didn’t have to don white coats in a lab, Queensland producers took scientific research into their own hands to turn the tide on parkinsonia invasion.
The aim of the research, with MLA funding, was to develop a system for parkinsonia dieback, a phenomenon caused by native soil fungi.
Following initial research, Dr Vic Galea and his team from the University of Queensland’s School of Agriculture and Food Sciences devised a method of injecting healthy trees with fungi-filled capsules (which became a form of mycoherbicide).
While taking this experimental technology into the field was a ’gamble’, Vic said the response of landholders was overwhelmingly positive.
Producers take the reins
Vic led the Parkinsonia Dieback Trials, which kicked off in 2010, but it was the producers who answered the call and did the groundwork in establishing 72 trials across a catchment area which covered 60% of Queensland from Cunnamulla to the Gulf.
Following a series of workshops, 109 producers, with help from community group members and extension officers, took on the role of researchers, inoculating the parkinsonia trees on the trial sites with three different strains of fungi and observing the results.
Early signs of success
“The project proved that experimental technology was easily translated into industry practice, with high levels of success in establishment of disease,” Vic reported.
“Industry members indicated that with minor modifications and limited mechanisation of the inoculation process, this technology could easily be translated into industry practice.”
While the trials were only preliminary and initially involved 2.6ha of infestation, the fungi causing dieback is already seen as another weapon against the weed with producers taking it upon themselves to spread it even further.
Even in its native form, many landholders felt the technology would allow for spot treatment of parkinsonia infestations in a way that may be more convenient than herbicide use.
It was also highly compatible with organic farming, which is currently limited to physical control mechanisms for woody weed management. In many cases the trials are still in progress as the time to plant death is somewhat variable.
“However, the infection rates look good. The trials were effective in causing infection, the translation to death takes time and we are yet to be able to pin that down exactly; it varies from location to location,” Vic said.
“This is a biological process and can’t be compared to a chemical herbicide.”
Parkinsonia threatens rangelands and wetlands across Australia and is classified as a ‘Weed of National Significance’ due to its invasiveness, ability to spread and economic and environmental impacts.
“I’ve been working with producers for 25 years and this has been one of the best projects I’ve ever been involved in,” Vic said.
“I really enjoyed working closely with people from industry and seeing all the different groups talking together, learning from each other and sharing their valuable knowledge with me.”
What next?
Data collected from the trial sites will now be used for further study, as the research indicated variation in performance among the three test mycoherbicides across different locations.
Parkinsonia management techniques checklist
1. Herbicide control > Aerial application > Foliar (overall) spraying > Basal bark spraying > Cut stump application > Soil application
2. Mechanical control > Grubbing > Stick raking > Blade ploughing > Chain pulling > Cutter bar
3. Fire
4. Grazing management systems
5. Native organisms
6. Introduced biological control agents
7. Integrated management techniques
Source: Argentine Beef Packers S.A.