Herbicides for barley grass management

2018

Research organisatons
Funding source

Trial details

Aims

Barley grass continues to be a persistent grassy weed in low rainfall farming systems and current farming practices have selected for increased seed dormancy. This change in seed dormancy has resulted in Barley grass germinating later, and being much harder to control with knockdown and pre-emergent herbicides. In 2018 a range of herbicide strategies was tested for their effectiveness on a high density population of Barley grass.

Key messages
  • Infrequent rainfall events, poor weed germination early and dry conditions at seeding resulted in challenging conditions for early weed control and crop establishment in 2018.
  • In a high Barley grass weed situation herbicide mixes containing Sakura provided good weed control.
  • Trifluralin (1.5 L/ha) IBS followed by Lexone (metribuzin) (180 g) post emergent caused significant crop damage due to rainfall events following the metribuzin application.
  • Use as many options as possible to lower grass weed seed banks including two-year breaks.
  • Regularly test grass populations for herbicide resistance.
  • Aim to prevent 100% of seed from setting in all phases of the rotation.
Lead research organisation Eyre Peninsula Agricultural Research Foundation
Host research organisation SARDI Minnipa Agricultural Centre
Trial funding source GRDC EPF00001
Related program Maintaining profitable farming systems with retained stubble
Acknowledgments

Funded by the extension of EPF00001 GRDC Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula, finishing in December 2018. Thank you to Fiona Tomney and Steve Jeffs for helping collect data, and Ben Fleet and Andy Bates for technical advice and Leigh Davis, Landmark Wudinna, for the herbicide pricing information. Thanks to John and Clint Oswald for providing the trial site.


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

Method

Crop type Wheat
Treatment type(s)
  • Herbicide: Type
  • Herbicide: Timing
Trial type Experimental
Trial design Replicated

Minnipa 2018

Sow rate or Target density Scepter wheat was sown @ 65 kg/ha
Sowing machinery

Small plot

Sow date 12 June 2018
Harvest date Not specified
Plot size 12m x 2m
Plot replication 3
Plot blocking randomised complete block design with 3 reps x 12 m plots
Plot randomisation randomised complete block design with 3 reps x 12 m plots
Fertiliser

DAP @ 60 kg/ha at sowing

Herbicide

Herbicide treatments were applied using a 2 m shielded sprayer at 2 bar pressure with medium-coarse droplets (T11002 nozzles) and 80 L/ha water rate on 12 June for the pre-emergent herbicides.

The post emergent herbicide treatments were applied on 6 July with 6 mm of rainfall after application, and a total of 30 mm for the month of July.

Download the trial report to view additional method/treatment information

Download results

Trial results Table 1

# Treatment 1
Average barley grass weed density (plants/m2) Barley grass seed head length (cm) Crop Establishment (plants/m2) Chemical cost ($/ha) Barley grass (heads/m2) (heads/m2) Grain yield (t/ha)
1 Control Untreated 711 ab 63 178 bc - 907 c 0.32 e
2 Trifluralin (1.5 L/ha) 323 bcd 68 141 b 9 536 b 0.48 d
3 Trifluralin (2 L/ha) 296 bcd 61 153 bc 12 474 b 0.56 cd
4 Trifluralin (1.5 L/ha) + Diuron 900 (400 g/ha) (pre-emergent) 642 abc 64 182 bc 14 420 b 0.60 c
5 Trifluralin (1.5 L/ha) + Avadex (1.6 L/ha) (pre-emergent) 189 cde 66 107 a 25 579 b 0.64 c
6 Trifluralin (2 L/ha) + Avadex (1.6 L/ha) + diuron 900 (500 g/ha) (pre-emergent) 156 de 60 146 b 28 343 ab 0.63 c
7 Trifluralin (1.5 L/ha) + Boxer Gold (2 L/ha) (pre-emergent) 794 ab 63 162 bc 37 1089 c 0.35 e
8 Sakura (118 g/ha) (pre-emergent) 126 de 64 173 bc 40 86 a 0.98 ab
9 Sakura (118 g/ha)+ Avadex (3 L/ha) (pre-emergent) 74 ef 58 158 bc 70 81 a 1.07 a
10 Boxer Gold (2.5 L/ha) (pre-emergent) 1547 a 63 203 c 28 893 c 0.33 e
11 Boxer Gold (2.5 L/ha) (pre-emergent) + Sakura (118 g/ha) (pre-emergent) 28 f 65 122 a 68 109 a 0.93 b

Grain yield t/ha


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Average barley grass weed density plants/m2


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Barley grass (heads/m2) heads/m2


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Barley grass seed head length cm


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Chemical cost $/ha


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Crop Establishment plants/m2


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Trial results Table 2

# Treatment 1
Average barley grass weed density (plants/m2) Barley grass seed head length (cm) Crop Establishment (plants/m2) Chemical cost ($/ha) Barley grass (heads/m2) (heads/m2) Grain yield (t/ha)
1 Control Untreated 711 ab 58 c 178 bc - 907 c 0.32 de
2 Trifluralin (1.5 L/ha) IBS + Lexone (180 g/ha) (post) 126 c 76 c 41 a 15 542 ab 0.16 f
3 Boxer Gold (2.5 L/ha) (post) 689 a 58 c 150 bc 28 532 a 0.46 b
4 Glean (20 g/ha) (post) 1213 a 54 bc 134 b 1 916 c 0.39 bc
5 Monza (25 g/ha) (post) 534 b 45 a 134 b 10 426 a 0.66 a
6 Crusader (500 ml/ha) (post) 809 a 49 ab 137 bc 34 911 c 0.34 cd
7 Atlantis (330 ml/ha) (post) 910 a 57 c 147 bc 29 782 bc 0.27 e

Grain yield t/ha


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Average barley grass weed density plants/m2


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Barley grass (heads/m2) heads/m2


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Barley grass seed head length cm


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Chemical cost $/ha


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Crop Establishment plants/m2


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Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 12, Minnipa, SA Red loam
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 12, Minnipa, SA Calcarosol
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

Site 12, Minnipa SA 2018


Observed climate information

Rainfall avg ann (mm) 325mm
Rainfall avg gsr (mm) 242mm
Rainfall trial total (mm) 268mm
Rainfall trial gsr (mm) 208mm

Derived climate information

Site 12, Minnipa 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.




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Trial last modified: 04-06-2019 13:32pm AEST