| Researcher(s) |
Catherine Borger (DPIRD) Madi George Brad Joyce (ConsultAg) Tiarna Kanny |
|---|---|
| Contact email | catherine.borger@dpird.wa.gov.au |
| Contact phone | 0467816082 |
| Year(s) | 2019 - 2021 |
| Contributor | Department of Primary Industries and Regional Development WA |
| Trial location(s) |
Yandanooka, WA
|
| Related trials |
Barley grass is becoming an increasingly problematic weed in Western Australia. A GRDC funded project sought to increase adoption of integrated weed management tactics for barley grass, by working with grower groups to develop regionally appropriate rotations for optimal control.
A survey indicated that in growers in the northern wheatbelt felt that barley grass was most likely to be a major problem in pasture, and a common response is use of Group A herbicide to remove grass in pasture. However, given how easy it is to develop Group A resistance, the group wanted to investigate other chemical and non-chemical options in pasture, as well as the impact of late seeding and pre-emergent herbicide for barley grass control in crop.
This three year trial aimed to investigate slashing and spray topping in pasture in 2019, and then time of sowing and pre-emergent herbicides in wheat in 2020 and canola in 2021.
Three years of control reduced barley grass density from over 1000 plants/m2 to 2-14 plants/m2 across the whole site.
The diverse rotation, including pasture and canola break crops, allowed a range of herbicides from different mode of actions and control of late emerging barley grass cohorts.
Two years of seed set prevention was not sufficient to remove the barley grass. Barley grass has a seedbank that lasts at least 3-4 years.
The barley grass density at the start of the season was over 1000 plants/m2 and the site was very uniform.
Spray topping or slashing resulted in 100% control of barley grass. The dry conditions prevented regrowth.
The higher seeding rate increased initial crop density. By August there was no difference in wheat tillers, due to a dry start to the season.
Barley grass density was initially low, with best control by TriflurX® and Sakura®. However, none of the pre-emergent herbicides offered full control, probably due to the low rainfall at the start of the season. New cohorts of barley grass emerged and weed density was high, given that there was no seed set in 2019.
Due to poor crop growth, the trial was updated to include a brown manuring treatment, and Spray.Seed® was applied to the whole trial area to avoid excessive barley grass seed production.
Barley grass density was lowest in the treatments with either TriflurX® or QPE with Roundup Plantshield®, compared to Roundup alone. Barley grass panicle number was too low to show a significant difference between treatments, but barley grass seed production was reduced in the treatments with TriflurX® or QPE® compared to Roundup alone.
The crop was healthy and highly competitive in 2021 due to high rainfall. The weed density was too low in all treatments to impact crop establishment or yield.
| Lead research organisation |
Mingenew-Irwin Group |
|---|---|
| Host research organisation |
Department of Agriculture and Food WA |
| Trial funding source | GRDC UOA1903-004SAX |
| Trial funding source | DPIRD WA |
| Related program |
Demonstrating and validating the implementation of integrated weed management strategies to control barley grass in the low rainfall zone farming system |
| Acknowledgments |
We would like to thank the Soullier family for providing the site, and Madi George and Kathryn Fleay at MIG for their assistance with the trial management and measurements. |
| Other trial partners | University of Adelaide |
| Crop types | Pasture: Mixed species Cereal (Grain): Wheat Oilseed: Canola |
|---|---|
| Treatment type(s) |
|
| Trial type | Demonstration |
| Trial design | Randomised,Replicated,Blocked |
| Sow rate or Target density | Not specified |
|---|---|
| Sowing machinery |
Note that the trial was volunteer pasture. The sowing date indicates when the pasture emerged and the harvest date indicates when the pasture reached maturity. However, the pasture was not sown or harvested. |
| Sow date | 14 May 2019 |
| Harvest date | 18 November 2019 |
| Plot size | 2.5m x 30m |
| Plot replication | 4 |
| Plot blocking | Yes |
| Plot randomisation | Randomised block design. |
| Fertiliser | Not specified |
| Herbicide |
Treatments
26 August 2019. Early spray top. Ester at 500 mL/ha, glyphosate at 2 L/ha, plus 0.2% wetter and 1% Amsul 17 September 2019. Late spray top. Ester at 500 mL/ha, glyphosate at 2 L/ha, plus 0.2% wetter and 1% Amsul 17 September 2019. Slashing |
| Sow rate or Target density | 40 or 120 kg/ha |
|---|---|
| Sowing machinery |
Wheat cv. Chief DBS bar (15m, 30cm spacing), John Deere box 22 cm row spacing |
| Sow date | 30 April 2020 |
| Harvest date | 18 November 2020 |
| Plot size | 2.5m x 30m |
| Plot replication | 4 |
| Plot blocking | Yes |
| Plot randomisation | Randomised block design. |
| Fertiliser |
30 April 2020. MAPSZC 50 kg/ha, Urea 30kg/ha |
| Herbicide |
Treatments:
25 August 2020. Spray.Seed 1.5L/ha over trial area. Due to dry start and high weed density, crop was brown manured 17 March 2020. Glyphosate 2L/ha and 2,4-D ester 30 April 2020. Pre-emergent herbicides applied according to treatments |
| Sow rate or Target density | 2 kg/ha |
|---|---|
| Sowing machinery |
Canola cv. InVigor® DBS bar (15m, 30cm spacing), John Deere box 22 cm row spacing |
| Sow date | 16 April 2021 |
| Harvest date | 19 October 2021 |
| Plot size | 2.5m x 30m |
| Plot replication | 4 |
| Plot blocking | Yes |
| Plot randomisation | Randomised block design |
| Fertiliser | Not specified |
| Herbicide |
Treatments
15 Apr 2021. TriflurX® 1.5L/ha. 14 May 2021 and 8 Jun 2021. Roundup Plantshield® 0.9kh/ha. 14 Jun 2021. QPE® 250mL/ha. |
| # |
Treatment 1
|
Treatment 2
|
Barley grass density (plants/m2) | Barley grass panicles (heads/m2) | Wheat (plants/m2) |
|---|---|---|---|---|---|
| 1 | █ Wheat 40kg/ha | █ TriflurX® 1.5L/ha | 9.6 | 26 | 63 |
| 2 | █ Wheat 40kg/ha | █ Luximax® 500mL/ha | 11.5 | 24 | 49 |
| 3 | █ Wheat 120kg/ha | █ Luximax® 500mL/ha + Monza® 25g/ha | 11.7 | 25 | 83 |
| 4 | █ Wheat 40kg/ha | █ TriflurX® 1.5L/ha + Monza® 25g/ha | 9.3 | 17 | 62 |
| 5 | █ Wheat 120kg/ha | █ TriflurX® 1.5L/ha + Sakura® 118g/ha | 2.3 | 45 | 100 |
| # |
Treatment 1
|
Grain yield (t/ha) | Crop Establishment (plants/m2) | Barley grass seeds (seeds/m2) | Barley grass density (plants/m2) | Barley grass panicles (heads/m2) |
|---|---|---|---|---|---|---|
| 1 | █ 2 x Roundup | 2 | 26 | 281 | 14.2 | 6.1 |
| 2 | █ TriflurX®, 2 x Roundup | 2 | 24 | 49 | 6.9 | 1.3 |
| 3 | █ 2 x Roundup, QPE | 1.9 | 27 | 12 | 4.2 | 0.5 |
| 4 | █ TriflurX®, 2 x Roundup, QPE | 1.9 | 26 | 0 | 1.7 | 0 |
| Rainfall trial total (mm) | 237mm |
|---|---|
| Rainfall trial gsr (mm) | 233mm |
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.
Plant Breeders’ Rights (PBR)
Some crop varieties used in research trials may be covered by Plant Breeders' Rights (PBR). Users should confirm PBR status of relevant varieties by searching the IP Australia PBR database, http://pericles.ipaustralia.gov.au/pbr_db/ or Variety Central (http://varietycentral.com.au/) and contacting variety owners for further information if required. Where possible, varieties have been listed according to their registered PBR name, although OFT cannot and does not guarantee that the information is accurate or complete.
Note that PBR cover is administered through the Plant Breeders’ Right Act 1994 (