Seed bank persistence of genetically modified canola in California

Environ Sci Pollut Res Int. 2012 Jul;19(6):2281-4. doi: 10.1007/s11356-011-0733-8. Epub 2012 Jan 19.


Introduction: Canola, which is genetically modified (GM) for tolerance to glyphosate, has the potential to become established as a new glyphosate resistant weed, thus reducing the effectiveness of glyphosate.

Methods: Volunteer from dormant canola seeds produced thousands of plants per hectare in the fourth year (2011) following a 2007 crop harvest. This occurred with no additional canola seed production since the 2007 harvest.

Results: Volunteer plants following harvests of annual crops are typically only a problem for the first year after harvest. In California, glyphosate is the core herbicide on over a million hectares of high value row, tree, and vine crops and new glyphosate resistant weeds reduce the effectiveness of glyphosate.

Conclusions: The combination of dormant seed and herbicide resistance makes GM glyphosate-resistant canola a new and difficult California weed which was first observed in the winter of 2009.

MeSH terms

  • Brassica napus / physiology*
  • California
  • Germination
  • Glycine / analogs & derivatives
  • Herbicide Resistance
  • Herbicides
  • Plants, Genetically Modified / physiology*
  • Seeds / physiology*
  • Time Factors


  • Herbicides
  • glyphosate
  • Glycine