It looked like something out of the Back to the Future film but everyday microwave technology could be tomorrow’s weapon in weed control for farmers.
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Graham Brodie from the University of Melbourne demonstrated a prototype of the technology at the recent Cotton Grower of the Year Field Day at Pine Ridge near Quirindi.
Field day visitors watched on sceptically (at first) as weed plants were zapped using an instrument connected to a microwave appliance, the same you would find in a typical household.
After only a few seconds treatment, the weeds were shrivelled and clearly distressed.
“You can hear the plants hissing and crackling, that’s actually the plants exploding,” Mr Brodie told the audience.
The research team’s information brochure says microwave energy kills emerging weeds very quickly but in larger amounts could be used to pasteurise soil, kill weed seeds and soil-borne pathogens.
The research is focused on developing innovations to counter traditional herbicide resistance and alternatives to mechanical control through tillage.
Mr Brodie started looking at farming applications for the technology after discovering its benefits treating wood in the forestry industry.
“We were getting full penetration 400mm into the stem,” Mr Brodie said. “It’s very focused.
“I thought we could do the same in agriculture.”
He suggested farmers use the microwave treatment to target problem areas for weeds.
“If you’ve got a issue in a paddock, you could use this once then go back to herbicide,” he said.
The research team said crops planted in microwaved soil generally performed “very well” with an 85 per cent reduction in weed emergence and 35-92 per cent increase in yields, compared to control crops.
The Department of Environment and Energy estimates weed management costs Australian farmers about $1.5 billion a year in control activities and a further $2.5 billion a year in lost agricultural production.
Non-chemical methods such as fire, steaming, grazing, soil mulching and physical removal had been tried but had their limitations.
It is anticipated the next microwave prototype being designed would cost landholders about $50-60 per hectare to treat with a travel speed of about 5-8km/hour.
