Growers in New South Wales are increasingly looking at their options for harvest weed seed control as the number one strategy for combating herbicide resistance and driving down the weed seed bank.
Grains Research and Development Corporation (GRDC) supported research shows seedbanks of annual weeds can be rapidly reduced when harvest weed seed control systems are used and this work has been boosted recently with the arrival of Associate Professor Michael Walsh in the northern region.
Internationally recognised for his work in this field, Dr Walsh has moved east from Perth where he worked with the Australian Herbicide Resistance Initiative (AHRI) at the University of Western Australia. His new role as Director of Weeds Research at the University of Sydney was created with the GRDC in response to the escalating problem of herbicide resistance in the northern region. This role is based at the IA Watson Grains Research Centre in Narrabri.
Dr Walsh has been integral in developing harvest weed seed control processes, and said his research showed that regardless of whether growers were using the Harrington Seed Destructor or a chaff cart behind the header, direct baling harvest residues or narrow windrow burning, the key was to capture and destroy weed seeds.
“Annual weeds such as ryegrass, wild radish, brome grass and wild oats have adapted to cropping systems, growing to similar heights as cereals and maturing at the same time as annual crops,” Dr Walsh said.
“There is some weed seed shedding at maturity which may make some growers a little skeptical about how much seed is captured at harvest, but research shows a high percentage of total weed seed production is retained on plants at a height that ensures collection during harvesting.
“But we know at the start of harvest high proportions of weed seeds are retained above a low harvest height (15 cm) for annual ryegrass (88 per cent), wild radish (99 per cent), brome grass (73 per cent), and wild oats (85 per cent) and by harvesting at this height these weed seeds are captured by the header and can be dealt with from there.”
Dr Walsh comes from a Victorian farming background, and completed his undergraduate degree at the University of Western Australia, before doing his masters at La Trobe University and then a PhD at the University of Wyoming in the United States.
In 1999 he joined AHRI, where he worked on developing systems targeting weed seed production at crop maturity, as well as the characterisation of herbicide resistant wild radish populations.
In his new role he will be focused on the GRDC northern cropping region, which he sees as the next frontier for the emerging threat of herbicide resistance.
Growers and advisers will have the chance to hear firsthand from Dr Walsh at the upcoming Gilgandra, Narrabri and Mullaley grains research updates.
The Updates will be held at Gilgandra on July 20, Mullaley on July 21, and at Narrabri on July 22.
Event details are available by following this link.
For more information or to register for either event, contact ICAN on 02 9482 4930 or this email address.
Dr Michael Walsh
02 6799 2201
Ellen McNamara, Cox Inall Communications
0429 897 129