Wheat varieties: managing yield and grain quality risk through sowing time and seeding rate at Mullewa


Research organisaton
Funding sources

Trial details

Researcher(s) Melanie Kupsch (Kunesh)
Anne Smith (DAFWA)
Christine Zaicou-Kunesch (Kunesh)
Year(s) 2012
Contributor North East Farming Futures
Trial location(s) Ardingly South, WA
Wheat varieties: managing yield and grain quality risk through sowing time and seeding rate at Mullewa locations

To improve crop production by determining the effect of sowing time and sowing rate on crop yield and grain quality risks of new wheat varieties.

Key messages

There was no influence of seeding rate on crop production in 2012 at Mullewa when the crop was sown close to the break. However there was a yield penalty with the higher seeding rate when the sowing time was delayed by a month. These results are in contrast to 2011 at Mullewa . Increasing seeding rate increased crop production when sown close to the break and there was no effect on  roduction with increasing seeding rate when seeding was delayed.


Emergence was staggered for the first sown treatments only. This is because seeding was on the 11th May into a drying seed bed. It had rain ed in April and early May. The second sowing time was on the 7th June. Rainfall in June was 56 mm.The seeding rate treatments targeted 100, 200 and 300 plants/m2. The actual plant population was 100, 147 and 200 plants/m2 respectively (averaged across variety and sowing time). The range in ears produced across treatments was not large however it was a significantly different between the highest (145 ears/m2) and the lowest seeding rate (137 ears/2) (ave across variety and sowing time).


At Mullewa, there was no interaction between seeding rate, sowing time and variety on crop yield. However, there was an interaction between seeding rate and sowing time on crop production for all varieties. When sown close to the break of the season, changing seeding rates did not affect crops yields significantly. In contrast to the first sowing time, the grain yield (averaged across all varieties) was significantly reduced at the higher actual plant population compared to the middle and lower targe ted plant populations of 100 and 147 plants/m2. Delaying seeding by a month later, reduced crop production by 500 - 600 kg/ha. This equates to 20kg/day/ha.

Emu Rock, Mace and Corack were the higher yielding varieties at each sowing time. Emu Rock and Mace are AH varieties, Corack is an APW variety.


There was no influence of seeding time, plant density or variety on grain protein (P>0.05). Initial assessment of grain screenings includes whole and cracked grain. Except for Emu Rock, screenings of all varieties were lower than 5% when sown at the first sowing time (P<0.05). Observations of Emu Rock at harvest suggest the screenings are a result of mechanical damage, rather than small grain (further measurements are to be undertaken to assess this).


Lead research organisation North East Farming Futures
Host research organisation N/A
Trial funding source GRDC DAW00218
Trial funding source DAFWA
Related program Wheat Agronomy-building system profitability in the Western Region
  • Christine Zaicou-Kunesh, Melanie Kupsch, Anne Smith (DAFWA)
  • Technical Services, DAFWA
  • Planfarm
  • AHRI
  • CSBP
  • Nufarm
  • GRDC
  • Landmark



Other trial partners Not specified
Download the trial report to view additional trial information


Crop type Wheat
Treatment type(s)
  • Sowing: Rate
  • Sowing: Timing
Trial type Experimental
Trial design Randomised,Replicated,Blocked

Ardingly South 2012

Sow rate or Target density Targeting 100, 200, 300 plants/m2
Sow date 11 May 2012 11th May 2012 and 7th June 2012
Harvest date Not specified
Plot size 20m x 1.54m
Plot replication 3

TOS 1: 11 May, 80 kg/ha Agras Xtra drilled with seed + 60kg/ha Urea topdressed.

TOS1: 11 - May, sprayed 100mL/ha Dominex +1.5 L/ha Triflur X + 1L/ha Sprayseed

TOS2: 07 - Jun, 80 kg Agras Xtra +50kg/ha 50 kg/ha Urea

TOS1+2: 25 - Jun, 0.5 L/ha Hasten + 700 mL/ha Velocity

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
Ardingly South, WA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Ardingly South, WA Tenosol
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 Ardingly South WA
2012 307.6mm
2011 381.3mm
2010 268.7mm
2009 297.9mm
2008 346.1mm
2007 276.3mm
2006 292.1mm
2005 292.2mm
2004 276.4mm
2003 272.1mm
2002 281.1mm
2001 265.6mm
2000 348.0mm
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.

Ardingly South WA


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 last modified: 25-06-2019 13:06pm AEST