Australia: Newer barley varieties show better resistance to powdery mildew

The availability of high yielding barley varieties with improved resistance to powdery mildew means Western Australian growers have viable options to reduce their exposure to the disease and the spread of fungicide resistance, The Stock Journal posted on August, 25.

Growers can inspect the performance of varieties with improved resistance at Grains Research and Development Corporation (GRDC) supported National Variety Trial (NVT) sites and during spring field days.

A strain of powdery mildew resistant to fungicide was recently confirmed under GRDC funded research by the Australian Research Centre for Necrotrophic Fungal Pathogens (ACNFP).

The case, involving resistance to tebuconazole from the triazole group of fungicides, is Australia’s first confirmed case of a broadacre crop pathogen resistant to a fungicide.

Department of Agriculture and Food Western Australia (DAFWA) barley senior research officer Blakely Paynter said many newer barley varieties offer significantly improved resistance to powdery mildew and are also high yielding and suited to WA conditions.

He said that, based on disease resistance ratings found in the recently released DAFWA Bulletin 4804 ‘Barley Variety Guide for WA 2010’, the key options for WA growers are:

•Barque (resistant);

•Buloke (moderately resistant);

•Dash (resistant);

•Fleet (moderately resistant to moderately susceptible);

•Oxford (resistant);

•Yagan (moderately resistant to moderately susceptible).

The new feed variety Scope, which will be available from AWB Seeds in 2011, is also rated as moderately resistant.

Mr Paynter said these varieties offer greater protection against powdery mildew than the varieties Baudin, Gairdner, Hamelin, Stirling, Vlamingh and Mundah, which are currently widely grown in WA.

“Notably, the malting variety Buloke and the feed variety Fleet are among the highest yielding varieties in all cropping areas of WA, based on current long-term NVT analysis,” he said.

“The feed variety Oxford also yields well in higher rainfall areas.”

Mr Paynter said powdery mildew is just one of the diseases which can limit barley yields and growers need to develop an appropriate disease management strategy for the barley variety they grow.

“An over-reliance on fungicide alone will not be effective or sustainable as an integrated management approach in the long-term,” he said.

25 August, 2010