[Stock & Land: 8 April, 2010, p. 24. By Gregor Heard] VICTORIAN grain growers have been kitted out with the latest weapons to fight herbicide resistance after attending a recent series of Integrated Weed Management (IWM) workshops, sponsored by the Grains Research and Development Corporation (GRDC), in Horsham. Co-ordinated and presented by specialist weed consultant Andrew Storrie of Agronomo and associate professor Chris Preston, University of Adelaide, the workshops highlighted the need to focus on reducing weed seed banks, to delay the establishment of resistance and effectively manage it once it occurs.
"We wanted growers to walk away with a greater understanding of how herbicide resistance develops and what they can do about it," Mr Storrie said.
"Feedback so far has been very positive, with growers indicating in exit surveys that they plan to change their weed management practices as a result of attending." Organisers of the workshops have been contacting participants of a previous round last year to see how their tactics have actually changed on-farm since participating.
Mr Storrie says most of them believe they have a greater understanding of the role and impact of weed seed bank dynamics and the importance of keeping weed numbers low in managing herbicide resistance.
"Asked about the use of multiple weed management tactics in the one year to reduce the weed seed bank, the most common response is that `their use had increased a lot'.
"Specific tactics they’ve changed since participat-ing in the workshop, and which have had the great benefit, include:
using crop rotations to allow use of a wider range of weed control tactics
crop competition and double knock tactics
varying herbicide use and options
windrowing and hay cutting
and, most importantly, developing a longer-term weed management plan for individual paddocks and the property.
"They’re also talking about better weed management more often with advisers and/or looking for information from other sources," Mr Storrie said.
"Herbicide resistance is a fact of life for growers these days, whether they already have it on their property or not.
"Hopefully these workshops will help them deal with the issue more easily, as well as limit the spread and impact of resistance."