Crop-topping cereals at Cummins

CC BY 4.0

Research organisaton
Funding sources

Trial details

Researcher(s) Michael Bennet (SARDI)
Ashley Flint (SARDI)
Brian Purdie (SARDI)
Year(s) 2009
Contributor Eyre Peninsula Agricultural Research Foundation
Trial location(s) Cummins,
Crop-topping cereals at Cummins locations

To investigate the impact of glyphosate as a crop-topping operation and the follow-on effects on grain yield and quality

Key messages
  • Crop-topping wheat with glyphosate can result in yield loss and grain size reduction if done too early.
  • Later crop-topping timings can produce grain quality and yield similar to untreated grain.
Lead research organisation Eyre Peninsula Agricultural Research Foundation
Host research organisation N/A
Trial funding source GRDC SA-EP-080906
Trial funding source Caring for our Country
Related program Eyre Peninsula Farming Systems
  • Thanks to Jeff Braun from Agrilink consultants for his help in trial design and treatment application; Brian Purdie and Ashley Flint for their efforts in applying the treatments, sowing and harvesting the trial, certainly a job well done; Martyn Chandler and the Landmark crew for help with spray timings; Brenton Spriggs for assessing the grain quality.
  • Thanks to LEADA, SANTFA and Caring for Our Country for supplying supplementary funding for the purposes of this trial.

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


Crop types Wheat
Treatment type(s)
  • Crop: Type
Trial type
Trial design

Cummins 2009 Wheat

Sow rate or Target density Not specified
Sowing machinery Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Cummins 2009 Barley

Sow rate or Target density Target 250 wheat and 200 barley plants/m2
Sowing machinery

small plot equipment

Sow date 22 May 2009
Harvest date Not specified
Plot size 10m x 1.5m
Plot replication 3

The plots were sown with 100 kg/ha DAP, with 100 kg/ha urea broadcast on 9 July.


Roundup PowerMax was applied at 1.2 L/ha through Lechler IDK nozzles producing a medium/coarse droplet spectrum with a water rate of 100 L/ha.

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
Cummins, Red clay loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Cummins, Sodosol
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 Cummins
2009 587.8mm
2008 561.2mm
2007 558.6mm
2006 600.7mm
2005 583.6mm
2004 580.0mm
2003 601.7mm
2002 577.2mm
2001 566.3mm
2000 541.0mm
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



Cummins 2009

Observed climate information

Rainfall avg ann (mm) 422mm
Rainfall avg gsr (mm) 342mm
Rainfall trial total (mm) 450mm
Rainfall trial gsr (mm) 380mm

Derived climate information



Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from
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 last modified: 06-08-2019 07:54am AEST