Effect of combinations of sowing time, seed rate and herbicides on brome grass management in barley

2019

Research organisatons
Funding source

Trial details

Researcher(s) Gurjeet Gill, Ben Fleet, Kate Maddern and Claire Browne
Contact email gurjeet.gill@adelaide.edu.au
Contact phone 08 83137744
Year(s) 2019
Contributor School of Agriculture, Food and Wine - The University of Adelaide
Trial location(s) Birchip, VIC, VIC
Effect of combinations of sowing time, seed rate and herbicides on brome grass management in barley locations
Aims

The aim of this experiment was to determine the effect of sowing time, barley density and herbicides on brome grass control.

Key messages

A field trial was undertaken at Kinnabulla (VIC) in 2019 to investigate combinations of sowing time, seed rate and herbicide treatments to control brome grass in barley. Spartacus CL barley was used in this trial to enable the use of Intervix® for post-emergence control of brome grass. In 2019, the trial site received 181 mm rainfall during the growing season (April-October), which was 23% lower than the long-term average for the site. However in December 2018, the site received a heavy downpour of 199 mm, which created good growing conditions for barley crop grown in 2019. In this trial, barley seeding rate did not have a significant effect on either yield (P=0.213), brome panicles/m2 at maturity (P=0.889) or brome seed set/m2 (P=0.409). This lack of effect of crop seed rate on the number of brome panicles and seed set could be related to the high plant available water during the crop and weed life-cycle or due to Spartacus being a less competitive barley cultivar due to its erect architecture. Time of sowing had a significant effect on brome panicles/m2 at maturity and brome seed set/m2. TOS 2 had a lower brome panicle density at maturity than TOS 1 across all herbicide strategies, which was most likely due to low pre-sowing weed kill in TOS 1 as brome grass had not yet germinated. However, brome population that had germinated after the opening rains was killed by glyphosate application prior to seeding barley in TOS 2. As the numbers of panicles were lower in TOS 2, brome seed set was also reduced in TOS2 relative to TOS 1. Herbicide strategy had a significant effect on barley grain yield. As the herbicides reduced the impact of brome on barley, its yield increased from 3.24 t/ha in the knockdown treatment (NIL), to 3.72 t/ha in the pre-emergent herbicides only and to 3.96 t/ha when the pre-emergent herbicides were followed by post-emergent Intervix. Somewhat surprisingly, TOS 2 produced higher yields than TOS 1 across all the treatments, with the greatest difference being 0.46 t/ha in the Nil herbicide treatments. However, the yield difference between the two times of sowing decreased when more effective herbicides were used (0.08t/ha difference between TOS 1 and 2 in pre-emergent only and 0.04t/ha difference when pre-emergent herbicides followed by Intervix). Higher barley grain yield in the later sown crop is most likely due to a significantly greater weed density in barley in TOS 1 than in TOS 2, as large numbers of early germinating brome plants were controlled with glyphosate knockdown in TOS 2. TOS 1 also experienced a mild frost during flowering, resulting in patchy frost damage. Furthermore, May 23 (TOS 2) sowing date still falls within the optimum sowing window for Spartacus, which is an early maturity variety, and TOS 1 on April 29 was earlier than optimum for this variety.

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

GRDC for providing funds for this research project.


Other trial partners Not specified

Method

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

Birchip, VIC 2019

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
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
Birchip, VIC, VIC Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Birchip, VIC, VIC Anthroposol
National soil grid Source
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.

Birchip, VIC VIC

NOTE: Exact trial site locality unknown - Climate data may not be accurate
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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 last modified: 18-05-2020 13:09pm AEST