Researcher(s) |
Nick Poole Darcy Warren |
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Year(s) | 2020 |
Contributor | Field Applied Research (FAR) Australia |
Trial location(s) |
Wallendbeen, NSW
|
To assess the value of pre and post GS30 defoliation in winter and spring germplasm grown in HRZ or high yielding regions of different season lengths.
Individual objectives specific to the trial were:
- Assess the dry matter offtake differences resulting from GS22, GS30 & GS32 defoliations and their effect on final harvest dry matter, grain yield and harvest index of spring versus winter wheat.
- Assess whether April sown spring wheat that has been “reset at GS32 (defoliated)” is higher yielding than GS30 and GS22 grazed and ungrazed crops.
- To assess whether the dry matter offtakes of longer season winter wheats at GS22 are more profitable (dry matter offtake and grain yield) than the same winter wheat defoliated at GS30.
• All defoliation treatments applied post GS30 reduced grain yield relative to the ungrazed and crops grazed at GS30.
• Although shorter grazing (hard grazing) produced more dry matter and gave slightly larger reductions in grain yield than light grazing, the differences were not statistically significant.
• With later grazing dates, due to a longer vegetative period, dry matter offtakes were significantly greater with RGT Accroc than with Trojan.
• The concept of “resetting Trojan” at GS32 was unsuccessful in terms of grain yield with a 22 April sown crop in the absence of any frost events.
• The development stage of grazing and degree of grazing (hard or light) were well correlated to preventing crop lodging due to reduced crop height and in some cases significantly less harvest dry matter.
• Unless the crop was reset with defoliation post GS30 at GS32 there was little noticeable difference in flowering date, although as would be expected RGT Accroc flowered later than Trojan.
Rotation position: Canola 2018, Wheat 2019.
Soil type: Clay loam
Lead research organisation |
Field Applied Research (FAR) Australia |
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Host research organisation | N/A |
Trial funding source | GRDC FAR2004-002SAX |
Related program |
FAR Hyper Yielding Crops 2020-2022 |
Acknowledgments | N/A |
Other trial partners | Not specified |
Crop type | Cereal (Grain): Wheat |
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Treatment type(s) |
|
Trial type | Experimental |
Trial design | Randomised,Replicated,Blocked |
Sow rate or Target density | 180 seeds/m2 (150 plants/m2 target) |
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Sow date | 22 April 2020 |
Harvest date | 28 November, 2020 (spring cultivars) & 14 December, 2020 (winter cultivars) |
Plot size | Not specified |
Plot replication | Not specified |
Fertiliser |
Please see trial report for details |
Fungicide |
Please see trial report for details |
Seed treatment | Vibrance/Gaucho |
Other trial notes |
The concept of “resetting” is specifically designed for early sowing spring wheat that develops too quickly from earlier sowing than would be recommended, in this case mid-late April. The idea is that defoliation later than GS31 specifically removes advanced main stems that would have been frosted due to their very early development. Please note this is an experimental approach and should not yet be applied to commercial acreage. |
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.