Grains Research and Development

Contacts

For further information contact:


Shahajahan Miyan

Research officer

Department of Agriculture and Food WA

75 York Road
Northam
WA, 6401

08 9690 2000

shahajahan.miyan@agric.wa.gov.au


Daniel Huberli

Plant pathologist

Department of Agriculture and Food WA

3 Baron-Hay Ct
South Perth
WA 6151

08 9368 3836

daniel.huberli@agric.wa.gov.au

Date: 30.06.2014

Managing crown rot in WA

Image of plant affected by crown rot

Despite a dry summer, the incidence of crown rot is expected to be high in parts of WA this year following a prolific year for the disease in 2013. Caused by Fusarium pseudograminearum and F. culmorum, the fungal disease can reduce grain yield and quality, and increase screenings.

Crown rot is hosted by all winter cereals and many grassy weeds. It affects roots and lower stems and is usually not detected until after heading. Significant yield losses can occur when high disease levels coincide with moisture stress during grain fill.

The disease can persist in infected crop residues for at least two years and be carried over in infected grass weeds. Crown rot is more common when susceptible crops (cereals) are grown sequentially or after long-term grass pastures. Its symptom of white heads can be confused with symptoms for take all disease, frost or copper and molybdenum deficiency. However, crown rot also causes a distinct golden brown coloured symptom on the stem base, and the white heads are scattered throughout the crop, but not in distinct patches (as with take-all).

A joint Department of Agriculture and Food WA (DAFWA) and Grains Research and Development Corporation (GRDC) study has in recent years found that there is an increased incidence of soilborne diseases, such as crown rot, when wheat is grown without a break crop.

Soil samples from 184 ‘Farm Focus Paddocks’ across WA regions, but mainly from the medium rainfall areas, collected in 2013 showed a general increase in soilborne diseases, compared with 2010. According to DAFWA plant pathologist Daniel Huberli the findings highlight that growers and agronomists should be on the lookout for crown rot and other soilborne diseases.

Root diseases can go unnoticed in a paddock until they build up over time and cause problems with the crop. With an increase in continuous wheat crops and reduced tillage systems, it is important for growers to keep an eye out as the growing season progresses. When checking a paddock, observe your crop closely, look for a lack of vigour or crown discolouration under leaf sheaths, and later in the season watch out for white-heads in the crop with associated crown discolouration.

For an overview of identification and control of crown rot in WA see: https://www.agric.wa.gov.au/mycrop/crown-rot-cereals

Identification:

Paddock

  • White heads scattered throughout crop but not in distinct patches (as with take-all)

Plant

  • Scattered single tillers and white heads
  • In severe cases whole plants develop white heads after flowering
  • Tiller bases honey-brown colour especially under leaf sheaths
  • Pink discolouration often forms around or in the crown or under leaf sheaths - with pink colour becoming very evident on infected plants left in a damp plastic bag for several days
  • Affected heads have shrivelled or no grain

For additional information on crown rot see the GRDC Crown Rot in Cereals fact sheet

For crown rot management strategies read more…

Read more...

Grains Research Updates

Where did the low levels of Fusarium head blight come from in 2016 and what does it mean

GRDC Project Code: DAN00176

Author(s): Steven Simpfendorfer(1), Daniele Giblot-Ducray(2), Diana Hartley(3) and Alan McKay(2)

Date: 28.02.2017

• Low levels of Fusarium head blight (FHB) observed in central and northern NSW in 2016 were predominantly caused by Fusarium pseudograminearum (Fp).
• This was the crown rot fungus (Fp) reminding growers that it does not disappear in a wet season.
• FHB infection caused by Fp has reduced risk for mycotoxin accumulation in infected grain but could have detrimental impacts on crop establishment if retained for planting in 2017.
• Planting Fusarium infected grain can also introduce seed-borne crown rot infection into clean paddocks, undoing rotational benefits associated with growing non-host crops.
• Growers are urged to test both their crown rot inoculum levels in paddocks prior to sowing and ensure their 2017 planting seed has no or low levels of Fusarium infection if they observed FHB in 2016, especially if considering durum production.
more

Grains Research Updates

Agronomic drivers of yield in rain fed wheat production systems of the Northern Grains Region

GRDC Project Code: DAN00181

Author(s): Rick Graham(1), Greg Brooke(2), Guy McMullen(1), Steven Simpfendorfer(1) and Neroli Graham(1)

Date: 27.02.2017

• Time of sowing (TOS) was found to be a key determinant of yield, in all three targeted geographic regions/environments, demonstrating significant declines in yield with delayed sowing vs. early-main season sowings. Higher yielding environments were impacted less by delays in TOS than lower yielding environments, with yield losses of 13% for the Liverpool Plains (LPP) vs. 34% and 46% for Trangie and Nyngan respectively.
• Variety and/or maturity type did not have a significant effect on yield with timely sowing in the early-main season window indicating that varieties were generally ‘plastic’ in their responses and broadly adapted to environments.
• Variety and maturity type did however influence yield potential with a delayed TOS at Nyngan and Trangie. The faster maturing varieties LRPB Crusader and LRPB Spitfire out yielded the main season variety EGA Gregory , with increasing plant population further enhancing yield potential. This demonstrates the scope for genotype (G) x management (M) options with delayed TOS in lower yielding environments.
• Altering variety and maturity type, and increasing targeted plant populations in response to delays in TOS could not fully compensate for the yield losses associated with delayed sowings.
• Yield responses to Nitrogen (N) and Phosphorus (P) fertiliser application rates, were variable and influenced by starting soil nutrition and seasonal conditions.
• Crown rot (CR) was a significant factor affecting yield potential at both Nyngan and LPP sites, decreasing yields by 25% and 12% respectively. This highlights the potential impact of CR on yield and the underlying need to ensure that yield potential is not constrained by biotic factors such soil-borne pathogens.
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Grains Research Updates

Cereal disease status and 2017 outlook

GRDC Project Code: DAS00139, DAN00175

Author(s): Hugh Wallwork, Marg Evans (SARDI)

Date: 07.02.2017

Eyespot was once again found more widely in 2016 than in previous years and higher inoculum levels are likely to be present in 2017. As yield losses are becoming more common, growers in disease prone areas should be aware of the symptoms and effective management strategies.
more

Grains Research Updates

Resistance and tolerance Where we are with crown rot breeding

GRDC Project Code: US00075

Author(s): Philip Davies, University of Sydney

Date: 22.07.2016

Significant variation exists in varieties performance under crown rot, representing opportunities for intervention in crown rot management.
Varietal performance under crown rot is made up separately of resistance and tolerance, as well as the yield potential of the variety.
The current simplistic R to S resistance rating system does not adequately represent a variety’s true performance in crown rot conditions, as it neglects both the tolerance and yield potential of the variety.
A more informative rating system for crown rot is required which accounts for a variety’s resistance and tolerance to crown rot, and the variety’s yield potential.
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