Diagnosing Group A herbicide damage in canola

These are post-emergent grass control herbicides used for annual ryegrass and/or wild oat control in wheat, barley and broadleaf crops or non-selective grass control in broadleaf crops. Group A herbicides are generally safe on canola, but Dims may cause damage and yield loss.

Distorted flowering spike, flowers and pods
'Gummed-up' flowers that are retained causing aborted or malformed pods
Early damage causes darker, bent down leaves
Curled sometimes scorched leaves

What to look for

    Paddock

  • Vegetative stage: areas of dark green distorted plants particularly where plants are stressed.
  • After stem elongation: reduced flowering and distorted heads on sprayed areas.

    Plant

  • Mildly damaged vegetative plants are dark green and cupped downwards with minor leaf spotting and scorching, before recovering.
  • Flowering plants are smaller and produce fewer smaller flowering spikes.
  • Flowers may appear gummed-up, resulting in distorted heads, reduced pod set, and distorted pods.

Where did it come from?

  • Spraying stressed plants.
  • Higher application rates.
  • Use of non-recommended adjuvants.
Source URL: https://www.agric.wa.gov.au/mycrop/diagnosing-group-herbicide-damage-canola
This print version was generated at 10:53am on the 1st of June, 2023.
The original document was last revised at Wed, 12/07/2017 - 12:29pm

Important disclaimer

The Chief Executive Officer of the Department of Primary Industries and Regional Development and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.