Weed Science Research Group - Publications & Media

Weed science research group aerial photo

Outcomes from the Weed Science Research Group feature in a wide range of mediums.

These include fact sheets, GRDC update papers and Ground Cover(TM) articles. Our researchers are also often found speaking about their research in town halls, sheds and in the paddock beside their trials. 

For scientific journal publications - refer to our researcher profiles.


Weeds and Herbicides

Three of our researchers will be speaking at the Adelaide GRDC Grains Research Update this month. Adelaide, SA. Feb 11-12.

  • Alicia Merriam: Herbicide resistant common sowthistle and prickly lettuce: dispersal, seed biology and management considerations in lentils.
  • Gurjeet Gill: Problem weeds - management to minimise impact.
  • Chris Preston: Integrating new chemistries in the field.


Weedsmart logo
Will the new pre-emergent herbicides help combat alphabet-resistant ryegrass?

The new decade is bringing with it some truly new pre-emergent herbicides with activity on annual ryegrass. With multiple-resistance to current pre-emergent herbicides looming large, it is essential that plans are put in place to ensure that these new herbicides can do the job of keeping ryegrass numbers low well into the future. Chris Preston speaks about this for WeedSmart here.


Congratulations to Shannon Endersby for successfully completing her Honours studies.

Shannon Endersby spent the past year in our weed science group, investigating resistance to metribuzin in wild radish.


Alicia Merriam receives Postgraduate Symposium prize

Alicia Merriam is the recipient of the Sustainable Agriculture prize, courtesy of the ARC Research Hub's ‘Legumes for Sustainable Agriculture’.

Her winning presentation at the Waite's 2019 Postgraduate Symposium (Oct) was based on her doctoral work: 'Herbicide-resistant common sowthistle and prickly lettuce: Dispersal, seed biology and management considerations in lentils.'


Vigilance needed to manage glyphosate-resistant summer weeds. GroundCover™ Issue 137.

Glyphosate-resistant populations of flaxleaf fleabane and feathertop Rhodes grass have been found in eastern Australia. The best strategy for managing these summer weeds is a double-knock with glyphosate plus an effective alternative herbicide in the first knock and a robust rate of paraquat in the second knock.


canola flowering
GroundCover™ Issue: 138. Hybrid canolas to help in long-term ryegrass battle. 

Growing a hybrid canola variety rather than an open-pollinated variety has the potential to drastically reduce ryegrass seed-set for following seasons.
Christopher Preston.


Media spotlight archive

Out and about - community engagement

Our researchers are regularly out in the paddocks, at trial sites and in town halls speaking about weed management in Australian broadacre farming systems. You can find the data behind our researcher's GRDC Grains Research update presentations under our 'Research Updates' tab.

  • GRDC Grains Research Update Presentations. Adelaide, SA. Feb 11-12.
    • Alicia Merriam: Herbicide resistant common sowthistle and prickly lettuce: dispersal, seed biology and management considerations in lentils.
    • Gurjeet Gill: Problem weeds - management to minimise impact.
    • Chris Preston: Integrating new chemistries in the field.
  • Integrating new chemistries in the field will remain as Chris Preston's topic for presentations at the Balaklava (Feb 13),  Bendigo (Feb 25-26) and Bannockburn (Feb 27) GRDC Grains Research updates.


  • Weed control in the high yielding irrigated farming systems of Tasmania, was the topic for Chris when he spoke at the FAR Hyper Yielding Cereals Project field day. Hagley, Tas. Nov 14.
  • "What to expect from weeds and managing herbicide residues” was Chris' focus when he presented at 4 of GRDC's Dealing with the Dry Workshopsfollowed by a panel session on farming systems management. Lake Cullulleraine, Wentworth, Euston, Balranald Nov 6-8.
  • Chris Preston and Fleur Dolman were at Millicent, SA to speak about their demonstration trials showing ryegrass management strategies in the high rainfall zone. The role of integrated weed management, crop competition and new herbicides was Chris Preston's second topic to speak about at the MacKillop Farm Management Group (MFMG) crop walk . Oct 24.
  • Chris spoke to 100+ people about integrated weed management at the  SA Crop Technology Centre Field Day (FAR Australia and Landmark). Oct 24.
  • Chris Preston and Fleur Dolman were at Frances, SA to speak about their demonstration trials showing ryegrass management strategies in the high rainfall zone. Oct 17.
  • Chris Preston spoke about weed management in a variety of crop types, several times over, at the Southern Farming Systems (SFS) AgriFocus event held at Inverleigh, VIC. Oct 16.
  • Ben Fleet and Daniel Petersen were out in their Roseworthy paddocks talking about their research trials for the SA Crop Science Society. Oct 9.

Community Engagement Archive

canola flowering
Managing resistant ryegrass in canola with crop competition and pre-emergent herbicides

Greater weed control was achieved through crop competition offered by an hybrid triazine tolerant (TT) canola compared to an open-pollinated TT, especially when combined with an effective pre-emergent herbicide strategy.

Barley grass spike
Alternative herbicides for management of group A herbicide-resistant barley grass in field pea

The combination of group A herbicide-resistance plus high seed dormancy makes barley grass increasingly difficult for Australian farmers to control.

Feathertop Rhodes grass
Feathertop Rhodes grass: biology and management

Understanding the biology of feathertop Rhodes grass (FTR) will help guide management choices for successful long-term control.

windmall grass
Windmill grass: biology and management

An understanding of windmill grass (WMG) biology will help guide management choices to enable successful long-term control.

Statice (winged sea-lavender): biology, ecology and IWM tactics

Statice is emerging as a significant weed of field crops in the low to medium rainfall areas of southern Australia. It can be effectively managed with an integrated weed management (IWM) plan.

Ryegrass in pea IWM
Long-term control & seedbank depletion of annual ryegrass: management strategies

A succession of years with multiple and diverse control options used in varying cropping phases is central to successful ryegrass management.

clethodim frost
Maximise clethodim performance: impact of frost

Frost events in the few days before or after clethodim application can reduce activity of the herbicide on annual ryegrass.

Wild Radish graph
Herbicide resistant wild radish: take back control

Herbicide resistance in wild radish is developing fast. Implement an effectively timed 2-spray herbicide strategy and prevent seedset.

Pre-em herbicide + not enough soil disturbance = inadequate weed control
Disc seeding systems and pre-emergent herbicides

Using disc seeding systems to maximise weed control with pre-emergent herbicides whilst minimising crop damage is not cut-and-dry.

Our researchers have written many research update papers, which they presented at GRDC grains research updates across the southern cropping region or at Conferences. They provide excellent insight on current issues and topics within weed science, particularly herbicide resistance.


GRDC crop update papers


GRDC crop update papers
Articles from the 21st Australasian Weeds Conference
GRDC crop update papers

Our work is featured in GRDC's GroundCover™ publication.

Chris Preston, Canola crop

Does ambient temperature really affect herbicide performance?

Chris Preston: Ask an Expert for WeedSmart (2017)

Temperature affects the absorption, translocation and metabolic degradation of herbicides applied to plants. Herbicides applied under the wrong conditions can appear to fail, however the reason may not be herbicide resistance.


What is new in management of herbicide resistant weeds on fencelines?

Chris Preston: Ask an Expert for WeedSmart (2017)

Weeds growing along fences and other crop border areas are quietly gaining resistance to important knockdown herbicides like glyphosate, setting plenty of seed and are ready to move into neighbouring crops.

Peter Boutsalis

Can ‘survivor’ weeds still be susceptible to glyphosate?

Peter Boutsalis: Ask an Expert for WeedSmart (2016)

Dr Peter Boutsalis is in the thick of this issue, taking a leading role in testing for herbicide resistance and conducting random surveys across southern Australia to monitor the spread and evolution of resistance.

Greg Martin

Combating herbicide resistant wild radish

Case study: Greg Martin, Victorian Mallee

Early detection, a focused management strategy and controlling survivors is helping Greg Martin get the better of herbicide resistant weeds.



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