WITH increasing pressure on farmers to manage herbicide-resistant weeds, it might be a case of 'back to the future' with mechanical weed kill.
That's the proposition of a GRDC-funded project which has seen the development of mechanical weeding machine called the Weed Chipper.
Southern Dirt TECHSPO delegates heard from the project's engineering lead, Dr Andrew Guzzomi, The University of WA (UWA), who with Dr Carlo Peressini, UWA and University of Sydney director of Weed Science, Dr Michael Walsh, developed the machine.
It is a two-row bar employing an electric and hydraulic system embracing WEED-it sensors and cameras for site-specific weed control.
Mr Guzzomi paid tribute to Darkan farmer Ray Harrington for the genesis of the Weed Chipper.
"He posed a question of the possibility of a mechanical means of killing low weed densities," Dr Guzzomi said.
"It was taken up by the GRDC and the Weed Chipper is the result."
The prototype machine used to develop the system was a John Shearer Trashworker and it was thought at the time that a system could be developed to retro-fit to any bar.
"But a re-designed tyne assembly incorporating a single-acting hydraulic cylinder and springs meant we had to build a new bar," he said.
In action, the tynes, equipped with a standard sweep point, are in 'suspense' until triggered by a sensor which deploys the tyne and sweep into the ground to dig out the identified weed.
Once the task is completed the tyne returns to the 'suspense' position ready for the next activation.
"In terms of the technology involved, this machine operates in a similar way as a weed-seeking spray boom," Dr Guzzomi said.
"Weeds are sensed, though instead of spraying them, we chip them out."
According to Dr Guzzomi, the Weed Chipper has been designed to adapt seamlessly and quickly into grain-cropping systems.
"It has been designed to run at 10km/h and while this may be slower than a sprayer, the Weed Chipper can work around the clock in a wider range of environmental conditions," he said.
The Weed Chipper was field tested in Narrabri, New South Wales, with 100 per cent success rate and is now the subject of "commercial discussions".
"We are aiming for commercial release as soon as possible," Dr Guzzomi said.
