Zapping weeds with microwaves

COOKING MORE THAN THEIR GOOSE… Showing the power of the microwave weed killer, associate professor, Graham Brodie at Melbourne University campus, Dookie holds a punnet with half the plants just killed by the machine. Photo: Katelyn Morse
COOKING MORE THAN THEIR GOOSE… Showing the power of the microwave weed killer, associate professor, Graham Brodie at Melbourne University campus, Dookie holds a punnet with half the plants just killed by the machine. Photo: Katelyn Morse

For most of us, we probably think of microwaves being used to heat up our dinner and for those with a bit more knowledge of the subject, perhaps as high speed wireless transmission. But there is more to the technology than that.

For some years now, associate professor, Graham Brodie from the University of Melbourne, Veterinarian and Agricultural Science department at the Dookie campus has been working on using microwaves to kill weeds in an agricultural setting.

Over the last several years, the university has worked on the design and constructed a 2kW demonstration model, four-port microwave unit that does kill weeds. The unit is now being scaled up to make a 100kW model to service an industrial application, primarily for treating the weeds between crops such as tomatoes, strawberries and the like.

In the prototype demonstration, the plants subjected to the microwaves are almost instantaneously killed and it is able to isolate the weeds from an adjoining plant.

A company has been formed by the university to further development of the equipment and to pursue venture capital to help move the project into production.

Assisting Professor Brodie is research assistant, Dr Jamal Khan who is conducting research into the impact the microwaves have on the organisms such as bacteria, nematodes and fungi that reside in the underlying soil. According to Dr Khan, there is some impact however it is not significant.

Once developed, the machine will obviate the need for chemical herbicides to some extent and perhaps alter the shape of the industry. They anticipate the scaled up version of a production model may be available later this year.

The next stage would be to have a more portable, spot weeding model to complement the broadacre version.