Effects of time of sowing on sub-troprical grass establishment

CC BY 4.0

Research organisatons
Funding sources

Trial details

Researcher(s) Christiaan Valentine (DAFWA)
Year(s) 2012
Contributor West Midlands Group
Trial location(s) Eneabba, WA
Effects of time of sowing on sub-troprical grass establishment locations

To identify the optimum sowing time for establishment of sub-tropical grasses to the east of Eneabba.

Key messages
  • The early growth of the sub-tropical grasses (panic grass, Rhodes grass) was slow and they appeared to have cold stress.  The seedlings were cold stress with all three TOS and they took a while to recover.
  • An interesting observation was that the surrounding paddock was sown to a sub-tropical grass mix (Gatton panic and Rhodes grass) just before the 3rd time of sowing, however the early growth of the perennial seedlings in the paddock was superior to the small plot trials.  Gatton panic is apomictic (i.e. all plants are essentially clones), so any difference must be due to the environment.  In this case, the markedly stronger early growth and less cold damage maybe due to the improved nutrition from the fertilizer applied at seeding. 
  • To evaluate whether there was a nutrient deficiency an application of fertilizer - 150 kg/ha of DAP plus 100 kg/ha of MOP was applied to half of each rep in mid-December in a split plot design.  Subsequently there has been little rainfall, so no opportunity to measure a response.
  • By mid-February there was not a substantial difference between the three times of sowing for Rhodes grass and Gatton panic which makes sense as in effect the sub-tropical grasses all emerged in early to mid-September for all three TOS.  The only species to emerge in any numbers before the third TOS was perennial veldt grass. However, by mid-February about 35-40% of the veldt grass plants had died and many more plants were highly stressed and may die over summer –autumn.  Sowing veldt grass in late winter – early spring with the sub-tropical grasses may not work in that persistence over summer may be poor.  Perennial veldt grass is a C3 so does not have the same soil temperature requirements as the sub-tropical grasses (C4).  An autumn sowing may be more successful for veldt grass.
  • The results from the TOS at Eneabba in 2012 suggest little or no advantage in early sowing of sub-tropical grasses in early August.  The optimum sowing window appears to be late August with more flexibility with Rhodes grass than Gatton panic for early sowing. 
Lead research organisation Department of Agriculture and Food WA
Host research organisation West Midlands Group
Trial funding source Caring for our Country
Trial funding source DAFWA
Related program N/A

This trial is part of the Transforming the Northern Sandplain project which is funded by Caring for our Country and DAFWA and is part of the Future Farm Industries CRC.  Many thanks to Callum Scott for access to the site.

Other trial partners Not specified
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Crop type Grasses
Treatment type(s)
  • Sowing: Timing
Trial type Experimental
Trial design Randomised,Replicated,Blocked

Eneabba 2012

Sow rate or Target density 3-4kg/ha
Sowing machinery

Department of Agriculture cone seeder, set up for sowing perennial grasses with a modified scalping point, followed by a depth wheel for accurate seed placement with a press wheel in line.

Sow date 8 August 2012
Harvest date Not specified
Plot size 20m x 2.6m
Plot replication 3

No fertilizer was applied at seeding.


Knockdown - glyphosate - approximately 1 week before the first time of sowing.

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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
Eneabba, WA Deep sandy duplex
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Eneabba, 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 Eneabba WA
2012 107.4mm
2011 115.2mm
2010 103.6mm
2009 109.5mm
2008 121.9mm
2007 93.1mm
2006 92.1mm
2005 99.4mm
2004 91.9mm
2003 96.6mm
2002 79.7mm
2001 65.6mm
2000 92.9mm
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



Derived climate information

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

Eneabba 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 report and links

2012 trial report

Trial last modified: 09-07-2019 12:07pm AEST