Western Australia
April 21, 2015
DAFWA has warned barley growers to factor in management of diseases, like barley spot type net blotch (pictured), into their 2015 cropping programs or risk production losses.
Barley growers have been urged to factor in disease management as they plan their 2015 cropping programs.
Barley has enjoyed a resurgence in Western Australia in recent years, driven by increasing global demand for feed and malt grain, with more than one million hectares expected to be sown this season.
Department of Agriculture and Food research officer Andrea Hills warned growers to assess their crop’s disease risk and to plan accordingly.
Ms Hills said diseases like spot type net blotch (STNB), which has been prominent in recent years, would pose a risk to barley crops – particularly those sowing barley-on-barley.
“Early sown crops are likely to be exposed to high STNB disease pressure as fungal spores are initially released from barley stubbles after rain and when temperatures are between 15 and 25 degrees centigrade,” she said.
With more than 85 per cent of the State’s barley sown to varieties that are susceptible to STNB, Ms Hills urged growers to avoid high risk crop rotations and incorporate fungicide treatments into their budgets.
“Heavy barley stubbles from 2013 will still be releasing STNB spores that can infect crops this season,” she said.
“While there are range of effective foliar fungicides, basic agronomic measures, such as ensuring soil potassium levels are above 50 parts per million, can also assist crops.
“An application of fungicide at stem extension has been shown to be most effective, with a follow-up spray three to four weeks later in medium to high rainfall areas.
“Burning infected barley stubbles could be used as a last resort to reduce risk of STNB.”
Loose smut is another recurring risk, with the most popular variety, Hindmarsh, and the new malting variety, La Trobe, more susceptible than other barley varieties.
Seed dressings can be very effective in protecting crops against this disease but growers need to ensure application is even throughout a seed batch to maximise protection every year and to keep loose smut at low levels.
Testing in 2014 has shown the new barley leaf rust pathotype, discovered in 2013, is now established on the South Coast.
The previously resistant variety Bass and the new feed variety Compass are susceptible to this new pathotype, while the resistance rating of other barley varieties has not changed.
Ms Hills said that while the risk of barley leaf rust had been lowered this season, due to a dry summer, it was imperative to control any volunteer plants three to four weeks prior to sowing.
Powdery mildew continues to be a perennial issue for susceptible varieties, especially in southern areas.
Ms Hills said growers should take action to minimise the risk for certain varieties.
“Baudin, Gairdner and Vlamingh need up-front protection with a registered seed dressing or in-furrow treatment containing fluquinconazole, which is effective against fungicide resistant strains of powdery mildew. Growers should also budget for a foliar treatment for these varieties” she said.
“Bass, Hindmarsh and other moderately susceptible or better varieties are, however, unlikely to need powdery mildew fungicide protection at sowing.
“Growers will need to monitor their barley crops to ensure they detect leaf diseases early and treat at the most opportune time, when there is less than a five per cent disease present on leaves. Moderately resistant or better varieties rarely require any treatment for leaf diseases”
For more information about barley disease management visit agric.wa.gov.au and search for ‘barley disease’.
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