| Researcher(s) | N/A |
|---|---|
| Year(s) | 2017 |
| Contributor | Riverine Plains |
| Trial location(s) |
Telford, VIC
|
The aim of this work is to understand if growers can reduce soil weed seedbanks in high-yielding high-rainfall zones by adopting harvest weed seed control (HWSC) practices.
• Harvest weed seed control (HWSC) — the collection and/or destruction of weed seeds at harvest — is a non-chemical control method, which can be used to reduce the seedbank of weeds, such as annual ryegrass (Lolium rigidium).
• Techniques include mechanical weed destruction, or methods involving carting or baling chaff straight after harvest. Chaff can also be concentrated behind the header in a row, which is then left to mulch (chaff lining or decking) or concentrated in a narrow windrow behind the header and burnt (narrow windrow burning).
• A major premise of HWSC is that the targeted weed species retain a high proportion of their total seed production at crop maturity.
• There was no difference between a harvest height of 30cm and 15cm in terms of the number of weed seeds returned to the soil.
• In wheat crops with high annual ryegrass plant populations, a large percentage of the ryegrass seed matures and drops in the month before wheat harvest, limiting the effectiveness of HWSC in the Riverine Plains region. In 2017, approximately 30% of total ryegrass weed seeds were removed by the harvest process.
• HWSC could be used as one tool in a larger integrated weed management strategy.
| Lead research organisation |
Southern Farming Systems |
|---|---|
| Host research organisation |
Riverine Plains |
| Trial funding source | GRDC SFS00032 |
| Related program | N/A |
| Acknowledgments |
The project Harvest weed seed control for the southern high rainfall zone (SFS00032) is a GRDC investment led by Southern Farming Systems. Thank you to our farmer co-operators Baker Seed Co, the Trevethan family and the Inchbold family. |
| Other trial partners | FAR Australia |
| Crop type | Cereal (Grain): Wheat |
|---|---|
| Treatment type(s) |
|
| Trial type | Experimental |
| Trial design | Randomised,Replicated |
| Sow date | 28 April 2017 |
|---|---|
| Harvest date | 10 December 2017 |
| Plot size | Not specified |
| Plot replication | Not specified |
| @T1: GS13 | @T2: GS23 | @T3: GS87 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| # |
Treatment 1
|
Protein (%) | Screenings (%) | Grain yield (t/ha) | Test weight (kg/hL) | Log soil seed bank (plants/m2) | Log ryegrass plants (plants/m2) | Log ryegrass plants (plants/m2) | Log ryegrass spikelets (plants/m2) |
| 1 | █ 2016 Ryegrass sown 0/m2, harvest height 15cm | 8.14 | 0.69 | 3.24 | 74.51 | 1.57 | 1.98 | 1.92 | 2.31 |
| 1 | █ 2016 Ryegrass sown 25/m2, harvest height 15cm | 8.36 | 0.76 | 3.08 | 74.34 | 1.21 | 2.07 | 2.01 | 2.32 |
| 1 | █ 2016 Ryegrass sown 50/m2, harvest height 15cm | 8.78 | 0.68 | 3.1 | 74.08 | 0.77 | 1.96 | 1.73 | 1.94 |
| 1 | █ 2016 Ryegrass sown 75/m2, harvest height 15cm | 8.34 | 0.73 | 3.19 | 74.05 | 0.63 | 2.01 | 1.98 | 1.45 |
| 2 | █ 2016 Ryegrass sown 0/m2, harvest height 30cm | 7.49 | 0.63 | 3.13 | 74.13 | 1.45 | 2 | 1.94 | 2.39 |
| 2 | █ 2016 Ryegrass sown 25/m2, harvest height 30cm | 7.71 | 0.7 | 2.97 | 73.95 | 1.08 | 2.09 | 2.04 | 2.41 |
| 2 | █ 2016 Ryegrass sown 50/m2, harvest height 30cm | 8.13 | 0.61 | 2.99 | 73.69 | 0.65 | 1.98 | 1.76 | 2.03 |
| 2 | █ 2016 Ryegrass sown 75/m2, harvest height 30cm | 7.69 | 0.66 | 3.07 | 73.66 | 0.5 | 2.02 | 2.01 | 1.53 |
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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.
