Effect of seed rate and herbicides on annual ryegrass management in wheat

Trial In Progress

CC BY 4.0

Research organisatons
Funding source

Trial details

Researcher(s) Ben Fleet
Gurjeet Gill
Contact email gurjeet.gill@adelaide.edu.au
Contact phone 0428 592825
Year(s) 2022
Contributor School of Agriculture, Food and Wine - The University of Adelaide
Trial location(s) Gladstone, ACT
Effect of seed rate and herbicides on annual ryegrass management in wheat locations

This field trial at Gladstone was undertaken to investigate factorial combinations of wheat seed rate and herbicides on the management of annual ryegrass.

Key messages

Key messages
• A field trial was undertaken at Gladstone in 2022 to investigate combinations of wheat seed rate and herbicide treatments on annual ryegrass (ARG) control.
• Even though the increase in wheat plant density from 100 to 250 plants/m2 reduced ARG spike density by 19%, this was not statistically significant (P=0.225). However, ARG spike density was significantly affected by different herbicide treatments (P<0.001).
• Surprisingly Sakura® (pyroxasulfone) was relatively ineffective with more than 700 spikes/m2. In contrast, Overwatch® (bixlozone) treatment had significantly less ARG spike density. The most effective herbicide treatment was the combination of Overwatch® immediately before crop sowing (IBS) with early post-emergent (EP) Mateno Complete® (aclonifen, pyroxasulfone, and diflufenican).
• Overwatch® by itself produced wheat yield of 6.2 t/ha, which was almost 1 t/ha higher than Sakura®. The highest crop yield (7.03 t/ha) was achieved in the treatment where Overwatch® was followed by early post-emergent application of Mateno Complete®.

Lead research organisation School of Agriculture, Food and Wine - The University of Adelaide
Host research organisation The University of Adelaide
Trial funding source GRDC 9175134
Related program GRDC - Weeds

We thank GRDC for providing funding for this research.

Other trial partners Not specified


Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Herbicide: Type
  • Sowing: Rate
Trial type Experimental
Trial design Randomised,Replicated

Gladstone 2022

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Gladstone, ACT Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Gladstone, ACT Sodosol
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.

Gladstone ACT

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 https://www.longpaddock.qld.gov.au/silo/
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 report and links

Trial last modified: 29-03-2023 15:27pm AEST