Effect of sowing time, seed rate and herbicides on ryegrass management in faba beans (Frances, SA)

CC BY 4.0

Research organisatons
Funding source

Trial details

Researcher(s) Gurjeet Gill and Ben Fleet
Year(s) 2018
Contributor School of Agriculture, Food and Wine - The University of Adelaide
Trial location(s) Site 1, Frances, SA
Effect of sowing time, seed rate and herbicides on ryegrass management in faba beans (Frances, SA) locations

To investigate combinations of faba bean sowing time, seed rate and herbicide treatments for the control annual ryegrass (ARG).

Key messages

The average seedbank of ARG at the site was 3932 ± 270 seeds/m2. ARG plant density was significantly influenced by the time of sowing (P<0.001), herbicide treatment (P<0.001) and the interaction between the time of sowing and herbicide (P<0.001). The delay in seeding from TOS 1 to TOS 2 (16 weeks) caused a large reduction in ARG plant density. This was particularly evident in the untreated control in which ARG density decreased from 825 plants/m2 in TOS 1 to 31 plants/m2 in TOS 2 (96% reduction). This large reduction in ARG density due to delayed sowing is most likely related to an effective knockdown herbicide treatment after most ARG had emerged before TOS 2. Herbicide treatments reduced ARG plant density significantly in TOS 1, however herbicide effect on ARG plant density in TOS 2 was non-significant, possibly due to a much lower ARG density. While the delay in sowing significantly reduced ARG plant density (P<0.001), it did not significantly reduce ARG seed spikes (P=0.495). This result indicates that despite low ARG plant numbers in TOS 2, faba beans failed to compete effectively with ARG and suppress its growth. As a result, even at a relatively low density ARG was able to produce a large amount of seed for future infestations. Faba bean grain yield at Frances was significantly influenced by the time of sowing (P=0.033), seed rate (P<0.003), and herbicide treatment (P<0.001). Averaged across the seed rates and herbicide treatments, faba beans produced grain yield of 1.34 t/ha in TOS 1 as compared to 1.81 t/ha in TOS 2. Superior faba bean grain yield in TOS 2 In 2018 at Frances is most likely due to the reduction in ARG plant density.

Lead research organisation School of Agriculture, Food and Wine - The University of Adelaide
Host research organisation MacKillop Farm Management Group
Trial funding source GRDC 9175134
Related program GRDC - Weeds

We thanks GRDC for research funding and SARDI (Struan) for trial establishment and management.

Other trial partners SARDI, Struan
Download the trial report to view additional trial information


Crop type Faba beans
Treatment type(s)
  • Herbicide: Type
  • Sowing: Rate
  • Sowing: Timing
Trial type Experimental
Trial design Randomised,Replicated,Blocked

Frances 2018

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
Site 1, Frances, SA Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 1, Frances, SA Anthroposol
National soil grid Source
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



Derived climate information

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

Site 1, Frances SA


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: 24-04-2019 09:06am AEST