Roundup Ready Canola as a Resistant Weed

Roundup Ready canola may be a new California crop at some point in time, but is currently one of California's newest weeds. Roundup Ready canola is a weed because of its ability to produce a significant percentage of secondary dormant seed when...

December 21, 2010 | Source: Western Farm Press | by Douglas Munier and Kent Brittan

For related articles and more information, please visit OCA’s Farm Issues page, California News page, Millions Against Monsanto page, and our Genetic Engineering page.

Roundup Ready canola may be a new California crop at some point in time, but is currently one of California’s newest weeds.

Roundup Ready canola is a weed because of its ability to produce a significant percentage of secondary dormant seed when harvested under a Mediterranean climate. This secondary seed dormancy in combination with its glyphosate resistance makes canola a new difficult California weed.

Advertisement Roundup Ready canola may be a new California crop at some point in time, but is currently one of California’s newest weeds.

Roundup Ready canola is a weed because of its ability to produce a significant percentage of secondary dormant seed when harvested under a Mediterranean climate (Lutman et al. 1998). This secondary seed dormancy in combination with its glyphosate resistance makes canola a new difficult California weed.

Most annual crops only produce volunteer plants during the year following production; however canola is known for shattering large amounts of seed before and during harvest (Mallory-Smith & Zappiola 2008) and when buried, some seed enters a “secondary dormancy.” Even if all volunteer canola is controlled before it produces seed in the first year following canola, seedlings will continue to emerge for many years from dormant seed. Most of this dormant seed emerges in the first four years four years (Lutman 2003), but some can emerge up to 10 years after burial in the soil (D’Hertefeldt et al. 2008 and Lutman 2005.

Canola is a higher quality oil developed out of oilseed rape. Canola varieties are selections from several mustard species, but most varieties produced in the United States originated from Brassica napus, commonly called rapeseed mustard.