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

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, seed rate and herbicides on ryegrass management in wheat locations
Aims

This field trial was undertaken at Roseworthy in South Australia, a medium rainfall environment, to investigate factorial combinations of sowing time, seed rate and herbicides on the management of annual ryegrass in wheat.

Key messages
  • The site mean for ARG plant density was 845 plants/m2, which is a reflection of the high seedbank. Delay in sowing from TOS 1 to TOS 2, reduced ARG plant density by 27% in the control (knockdown only). Further delay in sowing (TOS 3), reduced ARG plant density by 39%. Among herbicide treatments, Overwatch + Avadex Xtra provided the greatest reduction ARG plant density in all TOS.
  • As wheat seed rate was increased from 100 to 200 seeds/m2, ARG spike density declined by 37%, which is quite similar to the previous results. Further increase in wheat seed rate had a marginal additional benefit for reducing ARG spike density.
  • As wheat seed rate increased from 100 to 200 seeds/m2, ARG seed set decreased by 41%. Further increase in wheat seed rate to 300 seeds/m2 only had a small additional effect on ARG seed set.
  • When only the knockdown herbicide was used to control ARG (control), wheat grain yield increased with delayed sowing, which is most likely due to improvement in ryegrass control. However when pre-emergent herbicides were used, wheat yield declined with delay in sowing. In these pre-emergent treatments, grain yield declined by >1 t/ha as crop sowing was delayed from 21 May (TOS 1) to 27 June (TOS 3).
  • Yield improvements of more than 3 t/ha were achieved by combining early sowing with optimum wheat seed rate and effective pre-emergent herbicides.
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 Weed: Ryegrass Cereal (Grain): Wheat
Treatment type(s)
  • Herbicide: Type
  • Sowing: Rate
  • Sowing: Timing
Trial type
Trial design

Roseworthy campus, University of Adelaide 2021 Ryegrass

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified

Roseworthy campus, University of Adelaide 2021 Wheat

Sow date 21 May, 3 June and 27 June
Harvest date Not applicable
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 report and links

2021 trial report



Trial last modified: 20-03-2023 16:34pm AEST