ELECTROCUTION for weeds? Sounds like a B grade movie in the Attack of the Killer Tomatoes genre.
But incredibly, the latest strategy to conquer weed resistance is soon starting field trials in Western Australia, in the next few weeks.
If the “electrocutor” really does what its proponents promise – destroy the cell walls of everything it touches – it still leaves a rather big elephant in the room.
Resistance has outlasted everything science can throw at it; and if electrocution does work but a few plants do survive, and like those which have gone before, do build resistance, it’s certainly worth pondering what sort of creatures will we find in our paddocks in the future.
The electro shocker has arrived in Perth and WA’s Department of Primary Industries and Regional Development (DPIRD), will join with Case New Holland Industrial to test the technology’s suitability to control weeds in Australian dryland and irrigated agriculture.
It will also examine which weeds are easiest to control with electricity and the technology’s potential uses in Australian agriculture to generate cost savings and influence crop yields.
The project also has support from the Grains Research and Development Corporation, Wine Australia, WA consultants AHA Viticulture and the Cotton Research and Development Corporation.
The Swiss-made Zasso Electroherb machine, based on Brazilian technology, uses mechanical power to produce a high voltage current, which is applied directly to plants via a series of electrodes mounted behind or in front of the tractor.
The electro-weeding process works by passing electricity through a plant by touching it with an electrical applicator, which causes the cell walls to be destroyed – killing the plant or suppressing growth.
The technology has not been tested under Australian field conditions before, although it is used in Europe on a small scale for horticulture and viticulture properties; and for roadside weed control.
DPIRD research scientist Miranda Slaven said electric weed control could be part of an integrated solution to reduce dependence on chemical inputs and create more sustainable farming systems.
“Finding alternative weed control strategies to chemical measures is important in Australia, due to increasing rates of herbicide resistance and increasingly discerning market demands,” she said.
“This new device is at the frontier of agricultural technology, and it is valuable to test it under Australian growing conditions to examine its potential application as a non-chemical methodology in our agronomic systems.”
A preliminary plot trial indicated volunteer crops and grass weeds could be the hardest to control, due to the plants’ high surface area and extensive branching of roots and shoots.
The device will initially be tested on its ability to control weeds on viticulture and horticulture properties and later, along roadsides and fence lines, as well as its use for fallow weed control at the department’s research facilities in the WA Grainbelt.
The research will target herbicide-resistant weeds, such as annual ryegrass and wild radish, and problematic agricultural weeds, such as feathertop Rhodes grass and fleabane, as well as perennial weeds, including kikuyu and wireweed.
The machine will be commissioned before being rolled out in the field and project lead, research scientist Catherine Borger, said a literature review and reports from Europe suggested soil health and soil biota were not compromised by the technology.
“Our research will include an analysis of the technology’s effect on soil health, including soil microbial density and diversity, as well as soil root pathogens, such as rhizoctonia,” Dr Borger said.
“We are also particularly interested to ascertain whether there is a potential fire risk during summer so the trials will be undertaken following safety training using the utmost safety procedures.
“A cost-benefit analysis will also be incorporated into the research to determine where this technology can provide economic benefits to the industry in WA.”
The two-year electro-weeding project findings will be shared with industry.
