Effect of sowing time x seed rate x herbicides on ryegrass management in barley

2019

Research organisatons
Funding source

Trial details

Researcher(s) Ben Fleet
Year(s) 2019
Contributor SARDI Minnipa Agricultural Centre
Trial location(s) Buckland Park, SA
Related trials
Effect of sowing time x seed rate x herbicides on ryegrass management in barley locations
Aims

Change in sowing time can have multiple effects on crop-weed competition. Delayed sowing can provide opportunities to kill greater proportion of weed seedbank before seeding the crop, but weeds that establish in late sown crops can be more competitive on a per plant basis. This is one of reasons why farmers who have adopted early seeding have reported excellent results in crop yield and weed suppression.  Therefore, it is important to investigate sowing time in combination with other practices across different rainfall zones. The review of Widderick et al. (2015) also recommended research on sowing time in many crops.  Delayed sowing can also reduce crop yield so the gains made in weed control may be completely nullified by the yield penalty.

 

There has been some research already on crop seed rate on weed suppression but none of these studies have investigated the benefits of higher crop density in factorial combinations with sowing time and herbicide treatments. Crop seed rate is an easy tactic for the growers to adopt provided they are convinced of its benefits to weed management and profitability.  Furthermore, growers in the low rainfall areas tend to be reluctant to increase their seed rate due to concerns about the negative impact of high seed rate on grain screenings.

 

This field trial at Minnipa was undertaken to investigate factorial combinations of sowing time, seed rate and herbicides on the management of annual ryegrass in barley.

Key messages
  • There were large weed control benefits of delayed sowing of barley at Minnipa. However, when a highly effective pre-emergent herbicide was applied the benefit of delayed sowing was negligible.
  • In barley a three week delay in sowing time did not significantly reduce grain yield as it did in the previous year in wheat. Lower yield penalty in barley from delayed sowing may be related to its earlier maturity and more competitive nature compared to wheat.

 

Lead research organisation School of Agriculture, Food and Wine - The University of Adelaide
Host research organisation School of Agriculture, Food and Wine - The University of Adelaide
Trial funding source GRDC 9175134
Related program N/A
Acknowledgments

The authors thank Bruce and Kathryn Heddle for hosting the site. Malinee Thongmee and Hue Thi Dang (University of Adelaide), Fiona Tomney, Steve Jeffs, Bradley Hutchings and Katrina Brands (SARDI) for their technical input to the trial. We also acknowledge the investment from GRDC for the research into ‘Cultural management for weed control and maintenance of crop yield’ (9175134).


Other trial partners SARDI Minnipa Agricultural Centre
Download the trial report to view additional trial information

Method

Crop types Weed: Ryegrass Cereal (Grain): Barley
Treatment type(s)
  • Herbicide: Type
  • Sowing: Rate
  • Sowing: Timing
Trial type
Trial design

Buckland Park 2019 Ryegrass

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Plot randomisation Not specified
Herbicide Not specified

Buckland Park 2019 Barley

Sow rate or Target density Multiple - please see report
Sow date TOS 1: 4 May; TOS 2: 24 May
Harvest date Unknown
Plot size 105m x 10m
Plot replication 3
Plot randomisation split plot design with three replicates
Herbicide

Multiple- please see report

Download the trial report to view additional method/treatment information

Download results

Trial source data unavailable: Trial may be in progress or trial results have not been recorded.

Trial results Key management operations undertaken at Minnipa trial site in 2019.

# Treatment 1
Treatment 2
1 Operation Details
2 Location Minnipa, SA
3 Seedbank soil cores 11 April
4 Plot size 1.5 m x 10 m
5 Seeding date TOS 1: 4 May TOS 2: 24 May
6 Fertiliser At sowing – DAP (18:20:0:0) @ 60 kg/ha
7 Variety Compass barley
8 Seeding rate 100 seeds/m2 150 seeds/m2 200 seeds/m2
9 Herbicides 4 May and 24 May (applied just before seeding) Boxer Gold 2.5 L/ha IBS Trifluralin 1.5 L/ha IBS Control (knockdown treatment only)
10 Trial design split plot design with three replicates
11 Measurements pre-sowing weed seedbank, crop density, weed density, ARG spike density, ARG seed production, wheat grain yield

Trial results Rainfall received at Minnipa in 2019 and the long-term average for the site.

# Treatment 1
Treatment 2
Treatment 3
1   Rainfall (mm)
2 Month 2019
3 Jan 4.0
4 Feb 1.2
5 Mar 0.2
6 Apr 11.0
7 May 57.2
8 Jun 56.4
9 Jul 15.6
10 Aug 19.2
11 Sep 53.6
12 Oct 3.4
13 Nov 7.0
14 Dec 6.4
15 Annual total 235.2
16 GSR total 216.4
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Buckland Park, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Buckland Park, 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 Buckland Park SA
2019 560.1mm
2018 594.1mm
2017 635.8mm
2016 617.0mm
2015 583.8mm
2014 621.7mm
2013 610.4mm
2012 617.2mm
2011 626.0mm
2010 557.3mm
2009 494.4mm
2008 462.3mm
2007 522.3mm
2006 579.1mm
2005 594.9mm
2004 562.3mm
2003 541.7mm
2002 538.8mm
2001 540.0mm
2000 488.7mm
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

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Climate

Derived climate information

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

Buckland Park SA

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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

2019 trial report



Trial last modified: 19-05-2023 14:29pm AEST