Table 4 Assessment of GM volunteers in field studies in GM oilseed rape and GM maize applications
| Â | Oilseed rape | Oilseed rape | Oilseed rape | Maize | Maize |
|---|---|---|---|---|---|
Assessment area | Agricultural plot | Agricultural plot | Agricultural plot | Agricultural plot (not used for maize cultivation) | Unmanaged area |
Methodology | Sowing of GM and non-GM plants together with the cover crop (various densities) | Scattering of GM seeds after harvest (various depths) followed by shallow cultivation | Assessment of occurrence of GM volunteers in the course of a variety trial | 200 maize seeds per plot scattered in fall by hand | Sowing of maize seeds (approx. 100 per plot), variable ground cover in unmanaged areas |
No. of sites | 1 | 1 | 2 | 3 | 4 |
Control measures applied | Herbicide treatments | Shallow cultivation followed by herbicide treatment | Shallow cultivations followed by herbicide treatment or ploughing in fall and tillage in spring | Herbicide treatments | None |
Type of following crop/crop rotation | Winter barley, winter wheat, sugar beet and without crop | None | Wheat, linseed | None | Not applicable |
Parameters assessed | No. of volunteers/m2 | % inhibition (parameter not defined) | Volunteer emergence (parameter not defined) | Volunteer plants | Replacement values calculated (i.e. ratio of no. of seeds produced by volunteers to no. of seeds sown) plus additional phenotypic parameters |
Duration of experiment | 7–9 months | 2 months | 2–4 months | 6–9 months | Not indicated (assessments made in the following year) |