A Queensland university says it has developed a fully-autonomous weed-killing robot that could cut the cost of weed control by 90 per cent, potentially saving the farm sector $1.3 billion a year.

The Queensland University of Technology's AG BOT II is about the size of a golf buggy, equipped with a rig for spraying chemicals and distributing fertiliser.

Agricultural robotics program leader Tristan Perez said the robot also had a camera array that allowed it to identify weeds in real time and decide the best way to eradicate them.

"The robot uses images from a camera, and then we have artificial intelligence that we have trained using examples, and based on that it looks up particular features," Professor Perez said.

"From there it classifies what type of weed is in the image.

"Based on that information it makes a decision whether to treat the weed with a chemical agent or the mechanical method."

Developed with a $3 million investment from the Queensland Government, it is hoped the solar-powered AG BOT II will help fight the worsening problem of herbicide resistance.

Some weed species are developing resistance to broad scale chemicals such as glyphosate and paraquat through a process of selection, where susceptible plants are killed but those with a naturally-occurring resistance gene are not.

Over generations of the weed, the gene becomes dominant, forcing farmers to find alternative and often costly ways to kill the weeds.

Loading

Robot offers new ways of dealing with weeds

In parts of Western Australia's grain belt, wild radish has developed resistance to at least four different groups of herbicide.

Some producers there are tilling their entire farm's topsoil down 30cm just to try to halt the germination cycle.

Professor Perez said using AG BOT II could not only offer an option for growers that could no longer use chemicals, but could also prevent new resistance emerging in weed populations.

"The robots operate at a lower speed, and this enables new ways of dealing with weeds," he said.

"We have demonstrated mechanical and chemical, but we are also looking at other types of agents to deal with weeds, such as microwaves.

"If the robot comes up with a weed that it knows is herbicide-resistant, then it could treat it mechanically.

"Alternatively, what we could also do is have different types of chemicals on the robot, and depending on the type of weed, you decide upon which chemical to use."

QUT estimates the robot could cost farmers about $20,000, and anticipates several would work together on each farm to speed up the eradication, eventually replacing tractors and other expensive farm equipment.

The robot could also reduce herbicide run-off into the Great Barrier Reef by reducing application rates through precision targeting.

Multiple on-farm applications

David de Paoli, managing director of Austchilli, Australia's largest chilli farm, saw the robot demonstrated in Bundaberg recently.

He said there were multiple applications for it in his operation.

"From scouting to knocking out weeds, to spot spraying, to precision application of chemicals and fertilisers, it's unbelievable what you can do with it if you really put your mind to it," he said.

Mr de Paoli said while he was not sure how much money AG BOT II could save him, it was important to move towards precision agriculture to cut costs.

"There will be a saving without doubt, because everything costs so much — fertiliser, broadacre application, water application on broadacre, weeding broadacre with fuel, and wear and tear," he said.

"When you start precise ag and start cutting costs, you'd be surprised how much you'd save in a year."

Mr de Paoli said he had seen the impact of herbicide resistance on his own farm, and producers were looking for alternative ways to combat the issue.

"Labour's too expensive to go in and manually remove every weed on your farm, so this is the next option before we get to the end problem," he said.

Tristan Perez says the next stage of the project will test the robots in an industrial setting. ( ABC Rural: Dominic Cansdale )

But Mr De Paoli said researchers still had a way to go to convince him to outlay money for an AG BOT II.

"I told them I won't give them any bloody cash but get out to my place, I'll put it through the wringer, work with our commercial people, our people that work every day with the problems," he said.

"Between commercial people and academia we'll make it happen, but until you do that you're going nowhere.

"Get it in the real world and two experiences come together — the experience of technology and the experience of been there done that. Then I'll buy it."

Professor Perez said the next phase of the project would develop two or three of the robots to be tested in a truly industrial setting.

"We're also discussing this with commercialisation partners because we would like to do the next design of the robot, which would be the commercial one, such that we can ensure maximum market penetration and adoption," he said.

"So that it's a good solution at an affordable price for farmers."