THE GRAINS Research and Development Corporation (GRDC) has highlighted a raft of investments it has made into developing non-chemical means of weed control.
Hitting back at criticism from some within the broader agriculture industry that there is an overreliance on herbicide and not enough investment in finding alternatives, GRDC senior manager of crop protection Ken Young said the GRDC was investing in a wide range of projects.
These ranged from strategies such as increased crop competitiveness across various climate zones in order to crowd out weed species through to harvest weed seed management, which includes concepts such as the Harrington Seed Destructor, chaff lining and narrow wind row burning.
Trevor Syme, vice chairman of the Western Australian No Tillage Farming Association (WANTFA), and a farmer at Bolgart, said post-harvest weed management was critical in his area in the western central Wheatbelt.
“There’s Harrington Seed Destructors, seed terminators, narrow windrow burning, chaff carts, chaff lining, I’d say around here 90 per cent of people are doing something post-harvest in order to keep weed seed numbers down,” Mr Syme said.
He said he looked forward to more investment in research in the space.
“It’s very important for us as no-till farmers to have those non-chemical options after harvest to allow us to get those seed numbers down and reduce the reliance on herbicides, given we don’t want to be tilling.”
Mr Syme said he would like to see more work on seed destructor units.
“It seems to be working well in terms of the concept but there do seem to be longevity issues with the units and they are still very expensive to fit, at around $160,000.
“I think if you could ensure better reliability and bring the price down the uptake would be much higher.”
The GRDC is co-investing with CSIRO to investigate wheat germplasm with increased vigor which would be available to cereal breeding companies to incorporate into their breeding programs.
Cereal lines with strong early vigour will be able to grow quicker than weeds thus out-competing them for light and moisture.
Overall, there is a wide array of projects looking at non-chemical weed control, looking at the different methodology required over the widely disparate climate zones that make up Australia’s cropping regions.
Dr Young said right across the country, GRDC stakeholders expressed a desire to see ongoing work on looking at non-chemical weed control, whether it be novel, blue-sky research or more systems-based studies.
“GRDC also recently embarked on an Innovation Call seeking innovative investments. Non-chemical weed control was one of the three major priorities identified by GRDC in terms of investment and research,” Dr Young said.
The importance of the push to find alternatives to herbicides is borne out in GRDC-commissioned research conducted by Charles Sturt University, the Queensland Department of Agriculture and Fisheries and the Universities of Adelaide and Western Australia with GRDC investment.
The five year long survey revealed that nationally, about 75 per cent of the populations of ryegrass tested are resistant to Group A ‘fop’ herbicides, ranging from 99 per cent in WA and 90 per cent in southern NSW around Wagga, to much lower levels in western NSW where cropping intensity is lower.
Dr Young said blue sky research was also an important component in the GRDC portfolio.
“There is investment in looking at whether lasers can be utilised to help control weeds along with microwave technology,” he said.
There was also research being undertaken into the impact of summer cover crops and whether they could have a meaningful impact in weed suppression.
In terms of specific work by species, sowthistle and fleabane have both been nominated as weeds becoming increasing big problems in Australian cropping systems and Dr Young said the GRDC was a partner in the Rural R&D for Profit program led by AgriFutures investigating in the concept of biological control of the weeds, a method which has had success in other thistle species.
Biological control involves using natural agents, such as fungi or insects, to control weed numbers.
Old fashioned weed control techniques, such as tillage and slashing are also under the microscope through GRDC funding, with projects looking at site specific tillage and how it could be incorporated in a cropping system without potentially damaging side effects, such as erosion, a key reason for the popularity of no-till cropping in the past 20 years.