Genetically engineered oilseed rape in the US
Oilseed rape (canola) is only cultivated in a few federal states in the US. The total cultivation area is 1.6 million hectares. 1.3 million hectares are in the state of North Dakota. Commercial cultivation of genetically engineered oilseed rape started in 1998 and, at present, accounts for more than 90 percent of all oilseed rape fields in the US. The very first study in the USA on unintended dispersal demonstrated large-scale dispersal of herbicide tolerant oilseed rape along roadsides in North Dakota. 80 percent of all oilseed rape plants growing along roadsides tested positive for genetic modification. Half of the plants contained the cp4epsps gene for glyphosate tolerance. The other half contained the pat gene that makes the plants tolerant to glufosinate. Some of the plants were tolerant to both herbicides. Ruderal populations were found mostly near storage facilities or grain elevators, but also along railway tracks. There have, as yet, been no follow up studies on persistence under regional conditions or introgression into wild relatives such as B. rapa.
Ruderal populations of glyphosate tolerant oilseed rape were also detected in California where variety trials with transgenic oilseed rape had been conducted. Transgenic plants were found along roadsides and in the vicinity of places where the combine harvester had been emptied.