Effect of row spacing, seedbed utilisation and pre-emergence herbicides on ryegrass management in wheat (Minnipa, SA)

CC BY 4.0

Research organisaton
Funding source

Trial details

Researcher(s) Ben Fleet
Gurjeet Gill
Year(s) 2018
Contributor School of Agriculture, Food and Wine - The University of Adelaide
Trial location(s) Minnipa, SA
Effect of row spacing, seedbed utilisation and pre-emergence herbicides on ryegrass management in wheat (Minnipa, SA) locations

To investigate the effects of crop row spacing, seedbed utilisation and pre-emergent herbicides on ryegrass management in wheat.

Key messages

The herbicide treatment had a significant effect on ARG density (P<0.001) in this field trial at Minnipa. Favourable rain events in June were highly suitable for the activity of both pre-emergent herbicides investigated in this trial. Averaged across the row spacing and SBU treatments, Boxer Gold and Sakura + Avadex reduced ARG plant density by 88% and 90%, respectively. The density of ARG spikes was significantly influenced by the herbicide treatment.  Boxer Gold reduced ARG spike density by 74% compared to the untreated control, whereas Sakura + Avadex caused 85% reduction in ARG spike density. The density of ARG spikes in Sakura + Avadex were significantly lower than in the Boxer Gold treatment. ARG seed production was also significantly affected by the herbicide treatment (P<0.001) but not by wheat row spacing (P=0.272) or seed boot design (P=0.994). ARG produced 5740 seeds/m2 in the untreated control, which was reduced by 74% by Boxer Gold and 86% by the mixture of Sakura + Avadex. Presence of ARG at 190 plants/m2 in the untreated control, reduced wheat grain yield by 11% compared to Boxer Gold or 8% compared to Sakura + Avadex. However, it was still profitable to control ARG with effective herbicide treatments. Based on cash grain price of Australian Premium Wheat (APW) of $400/t in 2018, Boxer Gold would be expected to increase the gross margin by $68/ha as compared $12/ha increase for Sakura + Avadex.

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

We thank GRDC for funding the project and SARDI, Minnipa (Amanda Cook) for local collaboration. We also thank Bruce Heddle for providing an excellent field site for this research.

Other trial partners SARDI, Minnipa
Download the trial report to view additional trial information


Crop types Weed: Ryegrass Cereal (Grain): Wheat
Treatment type(s)
  • Herbicide: Type
  • Sowing: Method
  • Sowing: Row Spacing
Trial type
Trial design

Minnipa 2018 Ryegrass

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified

Minnipa 2018 Wheat

Sow rate or Target density 200 seeds/m2
Sow date 13 June 2018
Harvest date Unknown
Plot size 1.5m x 10m
Plot replication Not specified
Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Minnipa, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Minnipa, SA Calcarosol
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 Minnipa SA
2018 184.8mm
2017 210.6mm
2016 200.8mm
2015 170.2mm
2014 211.3mm
2013 156.1mm
2012 192.4mm
2011 219.4mm
2010 221.2mm
2009 243.7mm
2008 200.2mm
2007 183.1mm
2006 202.3mm
2005 177.2mm
2004 180.6mm
2003 176.4mm
2002 156.7mm
2001 205.0mm
2000 207.8mm
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.

Minnipa 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 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

2018 trial report

Trial last modified: 03-01-2023 15:03pm AEST