Effect of cultivar, seed rate and herbicides on annual ryegrass management in canola

Trial In Progress

2022
CC BY 4.0

Research organisatons
Funding source

Trial details

Researcher(s) Ben Fleet
Gurjeet Gill
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
Effect of cultivar, seed rate and herbicides on annual ryegrass management in canola locations
Aims

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

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
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

Method

Crop type Oilseed: Canola
Treatment type(s)
  • Crop: Variety
  • Herbicide: Type
  • Sowing: Rate
Trial type Experimental
Trial design Randomised,Replicated

Roseworthy campus, University of Adelaide 2022

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Roseworthy campus, University of Adelaide, SA Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Roseworthy campus, University of Adelaide, SA Chromosol
National soil grid Source: CSIRO/TERN
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

Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Roseworthy campus, University of Adelaide 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.



Trial last modified: 29-03-2023 15:16pm AEST