Researcher(s) |
Ben Fleet Gurjeet Gill |
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Contact email | gurjeet.gill@adelaide.edu.au |
Contact phone | 0428 592825 |
Year(s) | 2022 |
Contributor | School of Agriculture, Food and Wine - The University of Adelaide |
Trial location(s) |
Roseworthy campus, University of Adelaide, SA
|
This field trial at Roseworthy was undertaken to investigate factorial combinations of canola type (herbicide tolerance package), canola seed rate and herbicides on the management of annual ryegrass.
Key messages
• This field trial at Roseworthy was undertaken to investigate factorial combinations of canola seed rate and herbicides on the management of annual ryegrass (ARG).
• Canola seed rate had a significant effect on crop density (P<0.001). Crop density achieved was 30 plants/m2 for the low seed rate and 50 plants/m2 for the high seed rate.
• ARG plant density in various canola cultivars x weed management strategies was <100 plants/m2 (Table 6). Among herbicide tolerant crops, Truflex® (TF) glyphosate tolerant system and LT (LibertyLink® + Triazine tolerance) canola had a significantly lower ARG plant density (P=0.019) than the TT (triazine tolerant) canola. Within a canola cultivar, differences in ARG plant density were only observed in TT canola where application of clethodim alone or clethodim + butroxydim significantly improved ARG control as compared to pre-emergent herbicides alone (HT 1 and 2).
• There were significant differences between canola cultivars in ARG spike density. Application of propyzamide before sowing followed by two applications of glyphosate in TF canola reduced ARG spike density to less than 1 spike/m2. In contrast, spike density of ARG in TT canola was significantly greater (42-191 spikes/m2). As ARG population present in the trial paddock was glyphosate susceptible, use of this herbicide on TF canola proved extremely effective for ARG control.
• When averaged across the four weed management strategies, TF (Nuseed Raptor) canola (4.338 t/ha) produced significantly higher yields than TT (HyTTec® Trophy) (3.669 t/ha) and LT (Invigor® LT4530P) (3.523 t/ha) (P<0.001; LSD = 0.189).
• In this trial, glyphosate application in the TF canola not only provided excellent ARG control, but it also had excellent agronomic features, which resulted in grain yields well above 4 t/ha. Even though the differences between the herbicide treatments in TF canola were small, application of propyzamide pre-sowing gave a significant increase in yield relative to sole reliance on post-emergent glyphosate (HS 2 vs 4). Use of pre-emergent herbicide is likely to have reduced competition from ARG during the early vegetative stages prior to the use of glyphosate. Use of multiple modes of action is also beneficial for delaying the evolution of herbicide resistance in ARG populations.
Lead research organisation |
School of Agriculture, Food and Wine - The University of Adelaide |
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Host research organisation |
The University of Adelaide |
Trial funding source | GRDC 9175134 |
Related program |
GRDC - Weeds |
Acknowledgments |
We thank GRDC for providing funds for this project. |
Other trial partners | Not specified |
Crop type | Oilseed: Canola |
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Treatment type(s) |
|
Trial type | Experimental |
Trial design | Randomised,Replicated |
Sow date | Not specified |
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Harvest date | Not specified |
Plot size | Not specified |
Plot replication | Not specified |
Psuedoreplication | Not specified |
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.