Management of herbicide resistant barley grass in pulse crops


Research organisatons
Funding source

Trial details

Researcher(s) Ben Fleet (University of Adelaide)
Gurjeet Gill (University of Adelaide)
Barry Mudge (UNFS)
Lovreet Shergill (University of Adelaide)
Year(s) 2012
Contributor Upper North Farming Systems
Trial location(s) Baroota, SA
Management of herbicide resistant barley grass in pulse crops locations

Presence of increased seed dormancy in this grass weed species has enabled it to escape pre-sowing control tactics used by the growers. This explains why barley grass is a problematic weed in cereal crops. However, in some locations like Port Germein and Baroota districts, it has now become largely impossible to control in pulse crops. This islikely due to the presence of group A (fop & dim) herbicide resistance. Currently in these locations barley grass control is reliant on growing Clearfield wheat and the use of imidazolinone (group B) herbicides. This management strategy is at high risk of collapsing from the additional development of group B herbicide resistance. Previous studies have shown that resistance to group B herbicides can develop relatively quickly. Presence of large densities and repeated exposure to group B herbicides could rapidly lead to group B resistance in such barley grass populations. The extent of this resistance needs to be understood and effective management strategies to manage resistant barley grass in pulse crops developed.

Key messages
  • Increasing incidence of barley grass in cropping paddocks in southern Australia is likely to be associated with selection of more dormant biotypes by weed management practices used by growers.
  • In some districts, barley grass management is now being complicated by the evolution of group A resistance. However, there appear to be several effective potential herbicide alternatives for barley grass control in broadleaf crops.
  • Integrated weed management strategies are critical to delay onset of herbicide resistant barley grass.
Lead research organisation University of Adelaide
Host research organisation Upper North Farming Systems
Trial funding source GRDC UA00105
Related program N/A

Rupinder Saini, Amrit Riar and Malinee Thongmee for their technical assistance. Rob Dennis, for providing the field trial site and sowing the peas

Other trial partners Not specified
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Crop type Grain Legume: Field peas
Treatment type(s)
  • Herbicide: Type
Trial type Experimental
Trial design Replicated

Baroota 2012

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Other trial notes

Barley grass, like annual ryegrass, has the capacity to become highly resistant to group A herbicides (Figure 1). Even though resistance takes longer to develop in barley grass, its proactive resistance management is still vital. An integrated weed management strategy, combining multiple control tactics to reduce seed set, is required to delay the development of herbicide resistance. For example in a non-group A resistant population, pre-emergent herbicide + post-emergent group A herbic

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Trial results Table 1

@T1: % Seedset reduction
# Treatment 1
Grain yield (t/ha) Reduction in plants (%)
1 Sakura @ 118 g/ha IBS 2.29 99
1 Boxer Gold @ 2.5 L/ha IBS 1.41 74
2 Outlook @ 1 L/ha IBS 2.14 93
2 Raptor @ 45 g/ha + BS1000 0.2% PE 2.08 100
3 Trifluralin @ 2.0 L/ha + Avadex Xtra @ 2L/ha 1.32 71
3 Metribuzin @ 200 g/ha PSPE 0.82 46
4 Propyzamide 500 @ 1.5 L/ha 2.29 100
4 Diuron 900@ 1 kg/ha + Trifluralin @ 2.0 L/ha IBS 1.58 78
5 Trifluralin 2.0 L/ha IBS 1.19 68
5 Control 0.82 -

Grain yield t/ha


Reduction in plants %

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Baroota, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Baroota, SA Chromosol
Soil Moisture Source: BOM/ANU
Average amount of water stored in the soil profile during the year, estimated by the OzWALD model-data fusion system.
Year Baroota SA
2012 383.4mm
2011 367.1mm
2010 373.6mm
2009 341.8mm
2008 359.6mm
2007 354.6mm
2006 309.9mm
2005 321.8mm
2004 322.2mm
2003 325.0mm
2002 326.9mm
2001 379.0mm
2000 383.0mm
National soil grid Source: CSIRO/TERN
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties



Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Baroota SA

NOTE: Exact trial site locality unknown - Climate data may not be accurate

Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.

Trial last modified: 09-07-2019 16:22pm AEST