|Contributor||School of Agriculture, Food and Wine - The University of Adelaide|
To investigate factorial combinations of sowing time, cultivar, seed rate and herbicides on the management of annual ryegrass in triazine tolerant canola.
A field trial was undertaken in 2020 to investigate the effects of sowing time, canola variety, seed rate and herbicides on annual ryegrass management at a high rainfall site in Victoria (Winchelsea). Crop establishment at this trial site was significantly influenced by the time of sowing (P=0.006) and the seed rate (P<0.001) and there was an interaction between time of sowing and seed rate (P=0.014). Crop establishment was close to half of the target density, which may have been due to dry soil conditions in TOS 1 but there may also have been some slug damage. Select and Factor herbicides provided a much higher level of ARG control in TOS 2 than in TOS 1. Evaluation of weather data for the site showed that there were 4 frost events before the application of POST herbicides on 12 June in TOS 1, including the day of herbicide application. Previous research has shown a negative effect of frost on the level of weed control provided by these herbicides. Grain yield of canola was significantly influenced by sowing time (P=0.008), variety (P<0.001), seed rate (P<0.001) and herbicide (P<0.001). There were also significant interactions between time of sowing x variety (P=0.023), sowing time x seed rate (P<0.001) and sowing time x herbicide (P<0.001). Lower grain yield in TOS 1 compared to TOS 2 (2.3 Vs 3.4 t/ha) is most likely related to significantly lower canola plant density. The average grain yield of hybrid Ignite (3.13 t/ha) was significantly greater than that of open pollinated Wahoo (2.54 t/ha). There was a strong correlation between annual ryegrass spike density from herbicide treatments and canola grain yield (R2=0.96). Sowing time x herbicide treatments that provided weaker control of ARG also produced lower grain yield and vice versa. These results show that ARG can be highly competitive with canola in high rainfall environments and all efforts need to be made to achieve good crop establishment and selection of effective herbicide strategies.
|Lead research organisation||
School of Agriculture, Food and Wine - The University of Adelaide
|Host research organisation||
Southern Farming Systems
|Trial funding source||GRDC 9175134|
GRDC - Weeds
GRDC for providing funds for this research project and the Southern Farming Systems for managing the trial work.
|Other trial partners||Not specified|
|Sow date||Not specified|
|Harvest date||Not specified|
|Plot size||Not specified|
|Plot replication||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.