Threshold and cost of hand weeding low density wild radish


Research organisaton
Funding source

Trial details

Researcher(s) Peter Newman (Planfarm Pty Ltd)
Year(s) 2015
Contributor Planfarm Pty Ltd
Trial location(s) Geraldton, WA
Threshold and cost of hand weeding low density wild radish locations

To (i) develop a crop monitoring technique to assess wild radish density and provide growers with an estimated cost of hand weeding for a range of wild radish densities, and (ii) assess the efficacy of hand weeding of wild radish using backpacker labour.

Key messages
  • Hand weeding wild radish is feasible if you can pick the right paddock with a low enough weed density. The trick is picking the right paddocks.
  • This is a viable practice where wild radish density is approximately 5 to 10 plants/ha or less. At very low densities this practice is both economically and logistically feasible.
  • A side-by-side all terrain vehicle (ATV) with a trailer would be ideal. With this equipment, teams of two could work together with the driver picking radish given the ease of stepping into and out of these vehicles. This would reduce the cost and make life easy and safe for the workers.
  • Spray a boundary lap and any areas where high density is expected. We encountered high radish densities near the edges of paddocks which slowed down the process and increased the cost. These sprayed areas can also be hand weeded to remove resistant survivors.
  • Spend time assessing the paddocks. We managed to make accurate wild radish density assessments in one paddock. The problem was that we didn’t do enough assessment and we were faced with surprises in the other two paddocks.
  • Drones /weed detection will have their day. We have un-sprayed paddocks that now have as few as 2 wild radish per hectare in crop. It is simply not worth spending upwards of $25/ha to spray these crops not to mention the environmental issues. These paddocks are currently rare but they show what is possible.
Lead research organisation N/A
Host research organisation N/A
Trial funding source GRDC GIA00004
Related program Regional Cropping Solutions Network
Acknowledgments N/A
Other trial partners Not specified
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Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Management systems
Trial type Article/commentary
Trial design Not applicable

Geraldton 2015

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Psuedoreplication Not specified
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Download results

Trial results Table 1

# Treatment 1
Wild radish (plants/m2) Cost ($/ha)
1 Paddock 1 - 10.5ha 0.0026 39
2 Paddock 2 - 80 ha 0.00023 5.15
3 Paddock 3 - 9.6 ha 0.0097 51

Cost $/ha


Wild radish plants/m2

Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Geraldton, WA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Geraldton, WA Chromosol
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 Geraldton WA
2015 560.9mm
2014 548.3mm
2013 547.3mm
2012 541.0mm
2011 570.3mm
2010 544.6mm
2009 545.8mm
2008 514.3mm
2007 446.7mm
2006 497.9mm
2005 549.2mm
2004 528.5mm
2003 538.3mm
2002 526.7mm
2001 516.4mm
2000 514.0mm
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



Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Geraldton WA


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 report and links

2015 trial report

Trial last modified: 11-05-2023 17:32pm AEST