Row orientation and weed competition

2015

Research organisatons
Funding source

Trial details

Researcher(s) Amanda Cook (SARDI)
Nigel Wilhelm (SARDI)
Year(s) 2015
Contributor SARDI Minnipa Agricultural Centre
Trial location(s) Minnipa Agricultural Centre, SA
Row orientation and weed competition locations
Aims

To investigate the impact of row direction and row spacing on grass weed competition and ceral performance over three years.

Key messages
  • An east-west (E-W) sowing direction increased yield over north-south (N-S) sowing direction in an average season.
  • The results showed a decline in yield due to weed competition, but no effect on weed competition due to row direction. Sowing in an E-W direction may give a yield benefit with no difference in weed seed set.
  • The wider row spacing of 30 cm resulted in a yield reduction and greater weed biomass at harvest.
  • There were no differences in yield with ribbon seeding with either 18 or 30 cm row spacings, but ribbon seeding reduced ‘weed’ biomass.
Lead research organisation Central West Farming Systems
Host research organisation SARDI Minnipa Agricultural Centre
Trial funding source GRDC CWF0020
Related program Overdependence on agrochemicals
Acknowledgments

Thank you to Sue Budarick for processing the weed counts and managing the weed germination trays. Funded by the GRDC Overdependence on Agrochemicals project (CWF00020). Ian Richter and Wade Shepperd for technical support.


Other trial partners Upper North Farming Systems, BCG
Download the trial report to view additional trial information

Method

Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Sowing: Method
  • Sowing: Row Spacing
Trial type Experimental
Trial design Replicated

Minnipa Agricultural Centre 2015

Sow rate or Target density Weeds (oats as surrogate) 70 plants/m2
Sowing machinery

Sown with

1.Harrington knife point

2. Atom-Jet spread row ribbon seeding boot

Sow date 22 May 2015
Harvest date 12 November 2015
Plot size 20m x 2m
Plot replication 4
Fertiliser

18:20:0:0 (DAP) fertiliser at 60 kg/ha

Herbicide

The trial was sprayed with a knockdown of 1 L/ha of Roundup Powermax on 21 May and also a post-sowing pre-emergent spray of 1.5 L/ha of Sprayseed to control emerging self-sown cereal on 1 June. The trial was sprayed with 750 ml/ha Tigrex and 100 ml/ha of Lontrel on 27 July.

Download the trial report to view additional method/treatment information

Download results

Trial results Mace wheat growth, light interception (LAI), yield and grain quality with different sowing direction, row spacing and seeding systems at Minnipa 2015

# Treatment 1
Screenings (%) Late dry matter (t/ha) LAI (umols) Barley grass dry matter (t/ha) Protein (%) Yield (t/ha) Crop Establishment (plants/m2) Oat 'weed' dry matter (t/ha)
1 Row Spacing 18 cm 6.9 5.71 51.6 0.02 9.8 2.99 104 0.06
2 Row spacing 30 cm 6.3 4.64 45.9 0.01 9.9 2.33 156 0.12
3 knife points 6.4 5.81 48.7 0 9.9 2.82 124 0.14
4 knife points plus weed 7 5.74 50.4 0.01 9.8 2.53 131 0.1
5 ribbon 6 6.06 48.9 0.01 9.9 2.77 132 0.04
6 ribbon plus weed 6.9 5.73 51.3 0.04 9.8 2.52 133 0.08

Barley grass dry matter t/ha


Loading

Crop Establishment plants/m2


Loading

LAI umols


Loading

Late dry matter t/ha


Loading

Oat 'weed' dry matter t/ha


Loading

Protein %


Loading

Screenings %


Loading

Yield t/ha


Loading
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Minnipa Agricultural Centre, SA Red loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Minnipa Agricultural Centre, 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 Agricultural Centre SA
2015 286.4mm
2014 338.0mm
2013 287.6mm
2012 329.5mm
2011 356.6mm
2010 337.6mm
2009 369.5mm
2008 300.3mm
2007 285.9mm
2006 305.8mm
2005 267.5mm
2004 263.8mm
2003 263.8mm
2002 254.9mm
2001 317.8mm
2000 353.9mm
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

Loading

Climate

Minnipa Agricultural Centre SA 2015


Observed climate information

Rainfall avg ann (mm) 325mm
Rainfall avg gsr (mm) 241mm
Rainfall trial total (mm) 333mm
Rainfall trial gsr (mm) 258mm

Derived climate information

Minnipa Agricultural Centre SA

Loading
Loading
Loading

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

2015 trial report



Trial last modified: 11-12-2019 13:55pm AEST