| Genetically modified wheat resistant to the herbicide glyphosate (GR) was being evaluated for commercial use in Canada. Gene flow, seed and pollen mediated, by volunteer GR wheat was a major concern. Volunteer GR wheat control and fecundity was measured in glufosinate-resistant canola and peas. Imazamox + imazethapyr in peas were more effective in-crop than glufosinate in canola. The combination of pre-seeding and in-crop herbicides was the most effective at reducing volunteer wheat fecundity. A dose response study measuring volunteer wheat fecundity was conducted in glufosinate-resistant canola and imidazolinone-resistant canola. Imazamox + imazethapyr more consistently controlled volunteer wheat. Cereal crop competition was measured on native volunteer wheat populations. Barley crops seeded earlier relative to the time of the volunteer emergence had the greatest effect volunteer wheat fecundity. Volunteer wheat emerging prior to the crop was the most fecund but was the most affected by agronomic treatments. |
