Scientific-technical report ‘Farm Scale Evaluations’
In Great Britain, extensive field experiments have been carried out to investigate the consequences of cultivating genetically modified herbicide-tolerant (GMHT) crops with respect to biodiversity and outcrossing. In these so-called ‘Farm Scale Evaluations’ (FSE) the conventional oilseedrape, maize and beets is compared with the GMHT. The study established that the difference in herbicide use between the conventional crop and the GMHT crop led to a difference in biodiversity. The research did not focus on possible direct effects of genetically modified crops on the biodiversity, such as unintended effects on non-target organisms. Outcrossing was established in the case of maize. The researchers state that an isolation distance of at least 24.4 metres is necessary to stay within the threshold value of 0.9 % established by the EU. It might be possible to use these data, together with the data expected in the summer of 2004 for outcrossing in rape, to establish isolation distances with respect to the problem of coexistence. A changed agricultural regime cannot be viewed independently from the use of GMHT crops, as herbicide use and GMHT crops are inextricably linked to each other. In 2004, COGEM will issue a report concerning the public discussion that has arisen as a result of the FSE research. Finally, COGEM notes that the conditions in Great Britain are not completely equivalent to those in the Netherlands (for example, climate and tillage). This will need to be taken into account if the results are translated to the Dutch situation.