Weed Science Research Group - Resources & Highlights

Weed science research group aerial photo

Discoveries and advice from the Weed Science Research Group feature in a wide range of mediums.

These include fact sheets, GRDC update papers, Ground Cover(TM) and news 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 team member's researcher profiles.

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WeedSmart Articles
Read what Dr Gurjeet Gill and Dr Chris Preston have to say about weed management in recent WeedSmart articles. 

Will the new Group G herbicides help control herbicide resistance in broadleaf weeds?
Dr Chris Preston, August 2020.

Crop competition halves weed seed numbers.
Dr Chris Preston, July 2020

Does delayed sowing help manage weed populations?
Dr Gurjeet Gill, April 2020. 

Podcasts with our researchers by GRDC and WeedSmart.

Digging into the details of Feathertop Rhodes grass & blue lupins.

WA grower Jamie Greaves talks about blue lupins and then the focus shifts to Feathertop Rhodes grass and how this is proving to be an issue for growers in Northern NSW. Dr Chris Preston and Richard Daniel shed light on this issue and how to get on top of this weed. July 2020 (45 min)

Brome & barley grass: A lesson in resilience.

How farmers can change the nature of weeds is spotlighted by how quickly barley and brome grasses have reacted to our attempts to control them in cropping paddocks. On this podcast Dr Gurjeet Gill explains the adaption of these grasses, which are now lasting longer in the seedbank. Jan 2020 (10 min)

Making barley grass barely a problem.

Barley grass in the southern cropping region is becoming more prominent as a problem weed; as herbicide resistance emerges and as the plant evolves new behaviours. Hear what Dr Gurjeet Gill says about this topic and his region-wide series of trials that are currently underway. Jan 2020 (10 min)

​​​​​​​Weeds, Speed & Resistance.

The speed at which weeds develop resistance to herbicides makes farmer vigilance of paramount importance. On this podcast Dr Chris Preston outlines the current resistance status of both grass and broadleaf weeds. Dec 2019 (12 min)


Chris Preston: What you should know about the new pre-emergent herbicides. (16 min). 2020.

David Brunton: Evolution and management of Group J and K resistance in annual ryegrass. (9 min). 2019.

Gurjeet Gill: The race between weed evolution and weed control tactics. (6 min). 2018.

Peter Boutsalis: Tactics to improve glyphosate effectiveness. (5 min). 2018.

Chris Preston: Three tactics to get weed numbers down. (4 min). 2018.


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You don’t know what you don’t know about managing weeds.

Australia has an ever-increasing list of herbicide-resistant weed species and agronomists play a key role not only in identifying and tackling crop weeds but also in protecting chemistries. Join Dr. Chris Preston, Paul McIntosh and Ben Dawson. July 2020, 1 h 10 min.


ryegrass and wheat seedlings
Glyphosate Resistance Update

Dr. Peter Boutsalis discuss' how to optimise the efficacy of glyphosate and when to use the double knock strategy. Peter also shares the latest results from the random weeds survey in the Eyre Peninsula and southern Victoria. July 2020, 50 min.


Frances site wheat crop
Crop Competition Q&A

Dr. Gurjeet Gill & Dr. Michael Widderick answer questions that may have cropped up for participants of Crop Competition 101. They also provide a broader overview of the crop competition work being delivered by their respective teams. April 2020, 50 min.


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.

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.

  • Hart mini-field day - Managing weeds. Alicia Merriam, Chris Preston and Gurjeet Gill will be at Hart, SA on September 15th to speak about:
    • Managing wind dispersed broadleaf weeds and ryegrass in lentils - Alicia. 
    • New herbicides for managing ryegrass in cereals - Chris.
    • Chaff lining weed seed decay, as well as using crop competition for effective ryegrass control - Gurjeet.
  • Lameroo to Bowhill Driving Field Day with Mallee Sustainable Farming. Chris Preston participated to speak about rotations that manage barley grass. September.
  • Peter Boutsalis spoke at the WeedSmart Week event in Clare, SA. His presentation was titled 'Rotating buys you time, mixing buys you shots'. Follow the link to see video recordings and other snippets from the event. September.
  • Port Lincoln, SA GRDC Grains Research Update was held online, and included Chris Preston speaking on the topic of 'getting the best out of the new products for ryegrass control.' July. 
  • Fleur Dolman and Chris Preston were in Hatherleigh, SA, for the MFMG Results Day to present outcomes from their high rainfall zone ryegrass management project. March.
  • Chris Preston, Alicia Merriam and David Brunton presented and strengthened collaborations at the 2020 Weed Science Society of America (WSSA) conference, in Hawaii. March.
  • Integrating new chemistries in the field remained as Chris Preston's topic for presentations at the Balaklava,  Bendigo and Bannockburn GRDC Grains Research updates. February.
  • GRDC Grains Research Update presentations by  Alicia Merriam, Gurjeet Gill and Christopher Preston. Adelaide, SA. February.
  • 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

Read about weed management tactics for broad acre cropping. Our researchers have written and presented many research update papers for conferences and GRDC updates across the southern cropping region. These articles provide excellent insight on current issues and topics within weed science, including herbicide resistance and longevity.

Articles from the 21st Australasian Weeds Conference

Our work is featured in GRDC's GroundCover™ publication. (GroundCover™ Issues before Feb 2019


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