Providing practical information to help you protect your farm from biosecurity risks

No time for complacency as rust epidemic threatens

July 27, 2011

Barley in handsNow that most of the winter crop has been planted, it is important to start a regular monitoring program for pests, weeds and diseases.

Last year’s abnormally wet winter, followed by the January floods, has made weed control difficult for many growers and has increased the chance of potential epidemics of some pest and diseases. Vigilance will be needed to get weeds and pests back under control.

Last year, leaf rust caused significant damage to barley crops in Queensland. This year it has already been detected in both wheat and barley crops in the eastern cropping belt.

Remember, young weeds are easier to control than older weeds, and you should definitely control them before they seed. Another consequence of the extreme wet last season is the build up of inoculum for diseases in wheat, barley and chickpea. All three crops were heavily infected last year with a wide range of diseases.

Of big concern this year is the threat of a rust epidemic. The wet summer has favoured a green bridge for the carry-over of leaf and stem rusts in the eastern states. Already there are recordings of leaf rust in wheat and barley, as well as stem rust in wheat and oats. The risk of stripe, stem and leaf rust to wheat growers is potentially the worst disease risk in 40 years because of increased inoculum levels in crops during 2010, the weather patterns we’ve experienced and the potential for carry over on volunteer plants.

A new campaign has been launched to encourage growers to be proactive and plan their 2011 rust management strategy. The ‘Rust Bust’ campaign encourages wheat growers to use a range of tools for rust management including:

  • removing the green bridge (volunteer cereals)
  • growing varieties with resistance to stem, stripe and leaf rusts
  • applying fungicides to seed or to fertilisers for early season rust suppression
  • regular crop monitoring for rust and disease control when needed.

From a biosecurity perspective growers and agronomists need to be carefully monitoring for rust on all varieties. If rust is seen on varieties that should be resistant this may indicate that a new (exotic) strain has become established in Australia.

One such strain is Ug99, a new stem rust of wheat that is causing significant damage to wheat in many parts of the world. In barley, as well as endemic diseases such as leaf rust, net blotch and powdery mildew, a major exotic disease of concern is barley stripe rust, which is predicted to affect at least 80 per cent of our barley varieties. Any stripe rust seen on barley should be reported as it may mean a new incursion.

For chickpeas, growers should be monitoring for the endemic disease ascochyta 10 to 14 days after rain. If you find the disease you should refer to the Pulse Australia web site for control recommendations.

For more information on biosecurity in the grains industry go to the biosecurity section on the Plant Health Australia web site. Or call the Queensland Grains Biosecurity Office, Kym McIntyre on 0429 727 690. Rust Bust is an initiative of the Australian Cereal Rust Control Program consultative committee, supported by the Grains Research and Development Corporation.

 Author: Jo Slattery, Plant Health Australia