Effect of combinations of sowing time, cultivar, seed rate and herbicides on ryegrass management in canola

2021
CC BY 4.0

Research organisaton
Funding source

Trial details

Researcher(s) N/A
Contact email gurjeet.gill@adelaide.edu.au
Contact phone +61428592825
Year(s) 2021
Contributor School of Agriculture, Food and Wine - The University of Adelaide
Trial location(s) Roseworthy campus, University of Adelaide, SA
Effect of combinations of sowing time, cultivar, seed rate and herbicides on ryegrass management in canola locations
Aims

This field trial was undertaken at Roseworthy in SA, a medium rainfall environment, to investigate factorial combinations of sowing time, cultivar (hybrid Vs open-pollinated), seed rate and herbicides on the management of annual ryegrass in triazine tolerant canola.

Key messages
  • There was no effect of a two-week delay in sowing (P=0.672) on in-crop ryegrass plant density with 390 plants/m2 in TOS 1 and 401 plants/m2 in TOS 2. The combination of dry autumn and high seed dormancy in this ryegrass population is likely to be the reason for the lack of sowing time effect on weed density.
  • Combinations of pre- and post-emergent clethodim or clethodim + Factor failed to reduce ryegrass plant density below 200 plants/m2. Such a high level of ryegrass plant survival is likely to be related to the presence of a high level of group A/1 resistance in this population of ryegrass.
  • Ryegrass seed production was significantly affected by canola sowing time (P<0.001) with TOS 1 producing 35,757 seeds/m2 as compared to 49,368 seeds/m2 in TOS 2. Greater seed production with delayed crop sowing is likely to be the result of reduced competitive ability of canola with weeds when sown later.
  • Superior early crop vigour in Trophy was reflected in 21% lower ryegrass seed set than in Bonito (37536 seeds/m2 Vs 47,589 seed/m2). Canola sown at the higher seed rate (50 seeds/m2) resulted in a denser crop canola, which reduced ryegrass seed set by 38% (32,683 Vs 52,442 seeds/m2).
  • Combination of early crop sowing, higher seed rate, hybrid variety and herbicide treatments allowed canola to produce more than 2 t/ha yield at this site with a high seedbank of multiple herbicide resistant ryegrass. However, ryegrass population that survived management was able to produce up to 60,000 seeds/m2. Future management of this trial paddock would require at least 3 years of effective ryegrass management before normal crop management programs can resume.
Lead research organisation School of Agriculture, Food and Wine - The University of Adelaide
Host research organisation School of Agriculture, Food and Wine - The University of Adelaide
Trial funding source GRDC 9175134
Related program GRDC - Weeds
Acknowledgments

We thank GRDC for funding this research project.


Other trial partners Not specified
Download the trial report to view additional trial information

Method

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

Roseworthy campus, University of Adelaide 2021 Canola

Sow date 24 May and 10 June
Harvest date Not applicable
Plot size Not specified
Plot replication Not specified

Roseworthy campus, University of Adelaide 2021 Ryegrass

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
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: 20-03-2023 16:32pm AEST