EXCITING new research has found a way of non-chemical control for problem weeds, with good control of both the plants and the seed bank, with no side-effects.

The novel solution? Microwave energy.

Graham Brodie, senior lecturer at Melbourne University’s Dookie campus and an expert in agricultural engineering, said initial trials had found very positive results in terms of control of summer weeds.

“We are also confident it will work on autumn weeds prior to sowing, but the timing just meant we have worked on summer weeds so far.”

He said some prototypes had been assembled, featuring four modules.

“It’s still relatively small, but once get the proof of concept sorted we will work on bigger versions.”

It uses about eight to eleven kilowatts of power, or about the same amount as ten household microwaves, with five emitters in five rows.

The machine works on overheating the actual weeds and seeds in the top level of the soil.

“It will sterilize seed down to as much as five centimetres deep.”

Once the soil has cooled down, there is no further impact from the treatment, meaning it is safe to go in and plant.

“It is purely heat-based, which makes it better than fumigants in terms of with-holding periods.”

Mr Brodie said he expected the major application to be in horticulture at this stage, but added there was a lot of interest from the broadacre sector.

“With increased reports of weed resistance to chemicals, a method of controlling weeds without using chemicals will be very popular.”

While the initial usage will most likely be as a knockdown and a summer weed control, Mr Brodie said it may be possible to use the product in-crop.

He said trial work of using the microwaves in a precision agriculture system had shown promising results.

“You can irradiate individual rows without harming the crop in the other row.”

“You’d probably need equipment capable of an accuracy of five centimetres or better and have the appropriate shielding.”

He said the next step would be getting a product to the market that is economic to use.

“We’ve got to determine the interest in the market, but you can see it having a great future in the short-term with applications such as controlling weeds at a golf course, where with fumigants you have to wait a month before replanting.

“With the microwaves, you could be back out there virtually immediately.”

He said the research was progressing well, thanks to funding input from the Rural Industries Research and Development Corporation (RIRDC).