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Growave kills weeds using microwave technology

Australian startup Growave will soon start trials using microwave technology to manage and control weeds.

The technology will be tested in Australia on farmland at Dookie in Victoria and in the Lockyer Valley in Southern Queensland on an organic vegetable farm.

Growave developer and Melbourne University senior lecturer Dr Graham Brodie explains that the interest for the technology is significant. “I‘ve had contact with people from about 30 countries”, he says.

Herbicide resistant weeds

Dr Brodie, who is an electrical engineer, was working at the Faculty of Veterinary and Agricultural Sciences at the University of Melbourne, when he became increasingly aware of the problems farmers face when it comes to weed control. “Herbicide resistant weeds were becoming a very big issue”, he says. “So in 2007 I pulled apart a microwave oven and got the relevant pieces out. I then put it together in a way that I could project energy onto the soil and did some experiments.”

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Dr Brodie: "In 2007 I pulled apart a microwave oven and got the relevant pieces out. I then put it together in a way that I could project energy onto the soil and did some experiments." - Photos: Graham Brodie
Dr Brodie: "In 2007 I pulled apart a microwave oven and got the relevant pieces out. I then put it together in a way that I could project energy onto the soil and did some experiments." - Photos: Graham Brodie

Applying microwave energy to the ground

For Dr Brodie this was the beginning of a long journey. “Our present success with microwave technology has been lingering for a while”, he explains. “About 5 years ago I came up with a more efficient way of applying the microwave energy to the ground. We were able to confine the energy to a very small space. That then eventually brought about the start of our new company Growave earlier this year.”

Dr Graham Brodie:

There was a strong breeze blowing and there was a drizzling rain but the microwave technology proved to be very effective

He points out that microwave technology can treat weeds under almost any weather condition. “When you are spraying, you basically must do it on a still, clear day, because otherwise you get spray drift or it gets washed away in the rain. I tested the microwave out in the fields during a demonstration. There was a strong breeze blowing and there was a drizzling rain but the microwave technology proved to be very effective.”

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"Trials are on their way", says Dr Brodie. "We have a first prototype, set up on the back of a trailer of 8 feet by 5 feet. It has 4 microwave generators of 2 kilowatt, not very powerful but useful for doing experiments."
"Trials are on their way", says Dr Brodie. "We have a first prototype, set up on the back of a trailer of 8 feet by 5 feet. It has 4 microwave generators of 2 kilowatt, not very powerful but useful for doing experiments."

Control the seed bank

Dr Brodie says that the technology is very good in treating and killing herbicide resistant weeds. “It is a bit like using herbicides and it will cost you about the same. That is a big advantage of course. And another advantage is that if you treat the soil, you can also control the seed bank. That part of it is more like soil fumigation.”

Growave already has demonstrable data that the technology can handle weeds of reasonable size, up to knee height. The startup has demonstrated some good control of species such as serrated tussock and Chilean needle grass.

900,000 dollar investment

For the first stage of commercialisation an initial sum of 900,000 Australian dollar has been invested in Growave by the IP Group from the United Kingdom and GrainInnovate, the investment arm of Artesian Investments/GRDC in Australia.

The IP Group is a global investment firm which specialises in partnering on commercialising innovations developed by universities. GrainInnovate focuses on start-ups anywhere in the world that will have a benefit to the Australian grains industry.

Broadacre production system

“We will be looking for additional investment, but with these investments we can bridge the gap between our initial idea and taking it to the industry itself”, Dr. Brodie says. “We are now in the process of setting up our trials, so we can demonstrate the viability of the technology in a broadacre production system. And we‘re also doing some trials for the horticulture industry.”

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The trailer system of Growave was set up on a road side that was heavily infested with Chilean needle grass. This experiment proved very effective.
The trailer system of Growave was set up on a road side that was heavily infested with Chilean needle grass. This experiment proved very effective.

The work in the Lockyer Valley will be focusing on managing weeds in organic vegetable production, also because Growave is anticipating a growing demand for herbicide-free agriculture. “Trials are on their way”, says Dr Brodie. “We have a first prototype, set up on the back of a trailer of 8 feet by 5 feet. It has 4 microwave generators of 2 kilowatt, not very powerful but useful for doing experiments.”

Dr Graham Brodie:

Growave is one of the first initiatives that is getting this far with this technology

Growave is planning to gather lots of data. “But we are also inviting local partners to come and have a look. So they can think of how this technology works for them. And we are planning to develop some commercial prototypes. We are still finding out where we can find the best opportunity for investment. That will then decide what kind of commercial prototype we‘ll end up with.”

Commercial prototypes available mid 2020

Dr Brodie hopes to have some preliminary designs for commercial prototypes available mid 2020. “We just need to work out what the best starting point will be. We are certainly very interested in mounting the device on an autonomous robot type of machine in the future. I have got contact with companies that are involved in that. And an optical control will be ideal for killing weeds. The idea at this stage would be to have the machine set up on a trailer and running from the power take-off (PTO) of a tractor. That would be a very sensible way to run the power system.”

There is strong global interest in the technology. “I have had contact with people from about 30 countries now”, says Dr Brodie. “That is quite encouraging. Growave is one of the first initiatives that is getting this far with this technology.”

One comment

  • Pascal Bordeau

    Do you know if this technology is harmful to earthworms and useful soil bacteria ?

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