Weed Science Research Group
The Weed Science Research Group conducts research in the areas of integrated weed management, herbicide resistance, weed ecology and crop-weed interactions in Australian agricultural systems.
Our research projects focus on agricultural weeds of concern to growers in Australian broad-acre farming systems. Our projects adapt and evolve according to our latest findings and the needs of the agricultural community.
Crop competition for weed management and maintenance of crop yield
We investigate the integration of cultural weed control tactics with herbicides to improve crop competitiveness against weeds across different rainfall zones in the southern and western grain growing regions.
Our research will help determine the stability of the performance of different weed control tactics against ryegrass, brome grass and wild radish across the different rainfall zones and regions.
This GRDC-funded project is undertaken collaboratively with farming systems groups in the southern and western regions, enabling rapid transfer of project outputs to growers and advisers.
- Quantify the effect of combinations of crop competition factors on weed seed-set and crop yield; and
- Refine strategies and improve crop competitiveness across different rainfall environments in the southern and western regions of Australia.
Crop species in focus
- Southern region: wheat, barley, canola and faba bean
- Western region: wheat, canola and narrow leaf lupins
Weed species in focus
- Brome grass
- Wild radish
This project is led by the University of Adelaide and involves several groups including:
- University of Western Australia / Australian Herbicide Resistance Initiative - Dr Mike Ashworth (lead), Roberto Lujan
- Southern Farming Systems
- Birchip Cropping Group
- Mackillop Farm Management Group
- Hart Field Site Group
Funding: Grains Research & Development Corporation (GRDC)
Management of annual ryegrass in the high rainfall zone (HRZ)
Annual ryegrass can be particularly challenging to manage in the high rainfall zone (HRZ). Widespread resistance to post-emergent herbicides used in cereals means there is strong reliance on pre-emergent herbicides for ryegrass control.
Annual ryegrass seed banks in the HRZ tend to be high and there is late emergence of weeds due to the long and cool growing season. These late emerging plants contribute to high seed set that maintains populations.
As a result, ryegrass populations quickly rebound when management is reduced. Late maturity of cereals means that 50% or more of the ryegrass seed can be shed prior to harvest, reducing the efficacy of harvest weed seed controls. On the plus side, moderate populations of ryegrass (<100 plants per m2) have less impact on yield than they do in other regions.
High Rainfall Zone PortalProject goals
This project aims to demonstrate annual ryegrass management strategies in the HRZ, providing confidence for agronomists and growers to make on-farm management changes that are effective and profitable.
- 5 demonstration sites are established across southern Victoria and the south east of South Australia.
- Sites were sown to wheat or legumes in 2020, wheat in 2019, and break crops in 2018.
- Each site has 4 annual ryegrass management strategies of increasing management intensity, to demonstrate strategies that may provide effective and profitable management of annual ryegrass in the HRZ.
- The management strategies employed at each site have been developed with local agronomists.
- There were opportunities to view the sites during the season.
- Plot plans, treatments and data collected at each site is available via the HRZ ryegrass management portal.