This is the only machine of its type in the country.
A new tool for the use in the ongoing effort to manage weeds in cropping systems Australia-wide.
The need for this type of device was predominantly driven by the increased herbicide resistance
that we’re getting in Australian cropping.
Herbicide resistance is especially problematic in Australia’s northern farming systems
where glyphosate has been relied on for fallow weed control.
The north now has the highest number of herbicide-resistant weed species, compared to other regions.
So GRDC invested in the development of a new non-herbicide weed control option, a tillage
machine that could target weeds.
The R&D of this project is a partnership effort led by Michael Walsh at the University of
Sydney and I lead the engineering at the University of Western Australia and we have researchers
also involved at QDAFF in Toowoomba, and farmer groups who advise us as well. Proof of concept
came in the shape of a hydraulically activated, spring loaded, one tyne, weed chipping prototype.
This is the actual machine in 2016 at a UWA research facility.
However what was needed for a large-scale version was a durable multi-tyne system.
So the engineering team looked to an old farming favourite for their inspiration, the Shearer
Trash worker. Together with my colleague Dr Carlo Saropini at the University of Western
Australia we worked on trying to make that system very simple but robust and then in
partnership with a hydraulics company, David Knowling Hydraulics, to look at how we could
modify the hydraulics circuitry and then add some springs to the system to enable that
single actuating tyne to be held in a standby position above the ground and then when a
weed is seen by a triggering device such as a camera, those hydraulics trigger the solenoid
enables the tyne to go down very quickly into the soil and then return to the standby, ready
for all that to happen again.
Development of technology to trigger the hydraulics wasn’t included in the project’s scope,
so commercially available vision technology was partnered with the machine for its first
large-scale field evaluation, this time at Narrabri on the University of Sydney’s farm, Llara.
One camera is controlling five tynes.
The tynes are spread over two rows on the cultivar bar and when it encounters a patch
or a number of weeds they will trigger it. As well as evaluating the entire unit these trials
will be used to fine-tune the cameras to reduce excessive cultivation.
The machine’s operating speed is slow, compared to a spot sprayer, but running at 10km per
hour means fewer passes are required as it can target weeds at any growth stage.
It’s been calibrated to chip-out weeds at densities of one plant per 10 square metres
with convincing results.
The trials we’ve done with our colleagues at QDAFF in Toowoomba and here in Narrabri
have shown very high weed kill efficacy near essentially 100 per cent across a range of
problematic species and the only incidence where that wasn’t super successful was actually
due predominately to the shape of that sweep not being ideally suited but that’s an area
that can be overcome.
The sweep’s impact force and design is also being fine-tuned to minimise soil disturbance
while still inverting weeds to expose their roots to the hot, dry conditions which is
when the machine should be used as part of a grower’s weed management strategy.
This device predominately seems to have application in an integrated weed management system, one
in which you probably still are using spot spraying and then periodically introducing
something like this to get rid of those herbicide resistant weeds and as we move towards some
of those things that will be coming like swarms of robots weeding in the future.
Until then, grain growers across the entire country can look forward to the commercial
release of machines such as this in the near future.