Harvest systems a key part of weed management

Date: 08 Feb 2013

field with 3 tractors from a distance

Key points:

  • Harvest weed seed control systems facilitate lower in-crop weed population densities that cannot be achieved by herbicides alone;
  • These systems perfectly complement herbicide-based weed management programs;
  • The resulting lower weed populations are some insurance against further resistance evolution.

Australian cereal growers adopting harvest weed seed control systems (HWSC) are driving down weed populations to lower levels on their farms, and extending the life of the herbicides they use.

This is one of the messages Australian Herbicide Resistance Initiative (AHRI) researcher Michael Walsh will deliver to the Global Herbicide Resistance Challenge, supported by the Grains Research and Development Corporation (GRDC).

To be held at the Esplanade Hotel in Fremantle, Western Australia from February 18 to 22, 2013, the event is an international, multidisciplinary research conference addressing herbicide resistance – a major threat to global and Australian agriculture.

Dr Walsh said the problem of herbicide resistant weed populations globally was particularly severe in production systems where herbicide dependence resulted in a lack of weed control diversity.

“The dramatic consequences of this can be extreme levels of herbicide resistance in weed populations,” he said.

Dr Walsh said a glaring example of this was in the Western Australian grainbelt where annual ryegrass and wild radish populations were now very difficult to control with herbicides alone.

“Here, as in other regions of the world, herbicide resistance has resulted in a loss of valuable herbicide resources and driven the search for alternative weed control strategies,” he said.

Dr Walsh said it was well known that a key to managing dominant annual weed species was to prevent the input of fresh seed into their short-lived seed banks.

“We are lucky in Australia that our most problematic weeds hold onto their seed at harvest so we have the opportunity to remove or destroy some of these seeds,” he said.

Dr Walsh said a number of HWSC systems were now being used effectively to target weed seed production in the Australian grain belt.

“Although herbicides remain the number one weed control tool in Australian cropping systems, it is now clear that the inclusion of HWSC systems in weed management programs is enabling weed populations to be driven to very low levels, providing some insurance for the sustainability of remaining herbicide resources,” he said.

“What is absolutely evident is that herbicide sustainability in global cereal production areas will only be achieved if there is diversity in both the agro-ecosystem and in the herbicide and non-herbicide tools employed for weed control.”

Hundreds of delegates from more than 30 countries have registered for the Global Herbicide Resistance Challenge, which has attracted wide ranging keynote speakers from Australia and overseas.

Major issues to be discussed include the threat of herbicide resistance and its impact on global grain production, alternatives to chemical weed control and the latest gene modification advances.

More applied aspects of resistance and weed control will be the focus on February 21, and this day – for which one-day registration is available – is potentially of interest to agronomists and growers.

The conference also includes an optional field trip to York on February 22 to view harvest weed seed control practices and hear from WA’s top farmers.

Sponsors of the Global Herbicide Resistance Challenge include the GRDC; AHRI; Syngenta; BASF; Dow AgroSciences; Bayer CropScience; Kumiai Chemical Industry Co; and Sumitomo, Japan.

For more information or to register for the Global Herbicide Resistance Challenge, visit www.herbicideresistanceconference.com.au, or contact conference chair Lisa Mayer at AHRI on (08) 6488 7870 or lisa.mayer@uwa.edu.au.


PHOTO CAPTION:  Harvest weed seed control systems used by growers include windrow burning, the use of chaff carts and the Harrington Seed Destructor.

For interviews:

Michael Walsh, AHRI
(08) 6488 7872
0448 847 272


Natalie Lee, Cox Inall Communications
(08) 9864 2034; 0427 189 827

GRDC Project Code UWA000124

Region National