Grains Research and Development

Date: 07.09.2012

Schools help spread the search for mildew clues

Author: Nicole Baxter
PhD student Madeline Tucker checks her barley powdery mildew experiments at Curtin University in Western Australia.

Key points

  • PhD student searches Western Australia for clues to control barley powdery mildew
  • Hundreds of school students deployed to collect pathogen samples
  • Tests show resistance to some commonly used fungicides

A Curtin University PhD student in Western Australia is using people power to gather plant pathogens in a bid to develop better tactics for managing the costly barley disease powdery mildew.

Madeline Tucker, a 30-year-old molecular biologist at the Australian Centre for Necrotrophic Fungal Pathogens, was inspired to complete her PhD when working in the field as a research assistant gathering samples of disease-affected plants.

Now, with support from the GRDC, Ms Tucker is tasked with investigating, through DNA extraction, analysis and sequencing, the genetic structure of the pathogen responsible for causing barley powdery mildew.

From July to October each year she leaves the city to investigate calls from growers whose fungicides are no longer working. She brings back to the laboratory samples of the powdery mildew pathogen suspected to have mutated.

Ms Tucker also spends time liaising with schools participating in the Mildew Mania educational program – a community-based research project devised by her supervisor, Professor Richard Oliver, to track the spread of different strains of barley powdery mildew across WA. The project, initiated in 2011 and running again in 2012, is harnessing the enthusiasm of school children to trap local barley powdery mildew pathogens in special collection tubes that are sent to Ms Tucker for analysis.

Her 2011 results showed that of the 165 classes (from 123 schools) involved in the program, all were successful in gathering a strain of the disease. However, an unexpected discovery was the presence of the pathogen at Jurien Bay, 224 kilometres north of Perth – the furthest north this fungus has been found.

Ms Tucker says fungicide resistance tests of samples collected in 2011 produced variable results and she hopes further DNA analysis will clarify why some strains of powdery mildew develop resistance to fungicides and others do not.

“Given what we found in 2011, barley powdery mildew will be a big issue for growers in 2012,” she says.

To assist in preventing widespread losses, she encourages growers to:

  • plant barley varieties with improved resistance; and 
  • use fungicides with alternative modes of action such as Tilt Xtra® (a mixture of propiconazole and cyproconazole); Amistar Xtra® (a mixture of cyproconazole and azoxystrobin); Opus® 125 (epoxiconazole); or Opera® (a mixture of epoxiconazole and pyraclostrobin).

 

More information: 

Madeline Tucker, 

08 9266 9917, madeline.tucker@curtin.edu.au

www.grdc.com.au/GCTV

A fact sheet on barley powdery mildew is available at: www.grdc.com.au/GRDC-FS-ControlPowderyMildew

GRDC Project Code GRS10035

Region West, North, South