Pre-harvest weed control in Canola: Roundup Attack with IQ inside; registration update

Author: | Date: 27 Mar 2013

Aims

  • A submission has been made to the APVMA for registration of Roundup Attack with IQ inside used pre-harvest in canola – a new use pattern for Australian canola growers.
  • Trials demonstrate good levels of annual ryegrass seed set control – providing growers with another tool for weed seed management.
  • Application can be made over the top of standing canola (prior to direct harvest) or applied under the windrower/swather with specialized spray equipment.

Results

Nufarm field trials conducted since 2010 investigated efficacy and crop safety of glyphosate applied pre-harvest to canola.  Residue studies were also conducted under Good Laboratory Practice (GLP) as part of the project.

A submission was made to the APVMA in June 2012 to register Roundup Attack with IQ inside for pre-harvest use in canola.  Registration is targeted in mid 2013.  This will be the first registration of its kind in Australia.

We are hoping to provide growers with the flexibility to control weed seed set in canola with robust rates of Roundup Attack with IQ inside.  The use pattern will provide benefits to the grower such as lower weed numbers in the following season and faster desiccation of crop and weeds to allow speedier harvesting.

Efficacy trials conducted in canola demonstrated a good level of annual ryegrass control (reduced seed viability) particularly when applied at earlier crop stages corresponding to less mature ryegrass growth stages.  A rate response was evident (Figure 1) which supports the proposed maximum use rate for high levels of ryegrass control; particularly at later application timings.

Bar graph showing Canola-pre-harvest application of Roundup Attack with IQ inside Efficacy on annual ryegrass (seed germination) Average of 4 trials (2010/11).

Figure 1. Efficacy results (Annual ryegrass) from Roundup® AttackTM with IQ insideTM applied pre-harvest in canola.

Crop safety trials concluded that there were no significant losses in canola crop yield from the proposed use pattern where application can be made at a crop stage of 20% seed colour change.  These trials also confirmed no significant effect on canola oil content.

A new MRL is being proposed for canola seed as well as for straw and fodder.  Nufarm data shows that at the proposed maximum use rates the residues are comfortably below the new proposed limits.

Acknowledgements

This project has been partly funded by the GRDC

Contact details

Mark Slatter
Research and Development Officer, Nufarm
Horsham, Victoria
0438 064845
mark.slatter@au.nufarm.com