Coexistence of genetically modified (GM) and non-GM crops in the European Union. A review

Abstract

-The adoption of genetically modified (GM) crops in the European Union (EU) raises questions on the feasibility of coexistence between GM and non-GM crops. Regulations to ensure that different cropping systems can develop side-by-side without excluding any agricultural option are currently implemented or developed by member states. The aim of this review is to explore whether nationally or regionally proposed coexistence strategies comply with the general principles established by the European Commission that ask for science-based and proportionate coexistence measures. In the first part, existing legal requirements and potential sources of adventitious mixing are reviewed. It is discussed what type of coexistence measures might be necessary to keep GM inputs below the legal tolerance threshold of 0.9%. Concentrating on cross-fertilisation as the major biological source of adventitious mixing in maize, it is then assessed to which extent available scientific data on cross-fertilisation can explain the diversity of currently proposed isolation distances by several member states. In the second part, it is analysed whether currently proposed isolation distances reflect contending policy objectives towards GM crops that largely exceed the economic scope of coexistence. It is investigated how coexistence is intersecting with a wider debate about the role of GM crops in agriculture. Based on the analysis of existing cross-fertilisation data, it is concluded that some of the currently proposed isolation distances are not in line with the coexistence principles laid down by the European Commission: they are (i) excessive from a scientific point of view; (ii) difficult to implement in practice; (iii) rarely proportional to the regional heterogeneity in the agricultural landscape; and (iv) not proportional to the farmers' basic economic incentives for coexistence. Hence, the range of proposed isolation distances cannot simply be explained by different interpretations of available scientific data, possible error intervals and remaining uncertainties inherent in the scientific process. It is argued that other than scientific issues must be at play. One might thus claim that coexistence has become an arena of contending values and visions on the future of agriculture and on the role GM crops might play therein.adventitious mixing / Bt-maize / coexistence / cross-fertilisation / flexible measures / genetically modified (GM) crops / isolation distances / liability / fixed measures / sustainable development

Cross-fertilization between genetically modified and non-genetically modified maize crops in Uruguay

“…However, studies comparing results of these experiments found that cross-fertilization patterns are similar, notwithstanding differences in experimental approaches (Riesgo et al, 2010;Sanvido et al, 2008). In spite of similar patterns for cross-fertilization events, isolation distance between GM and non-GM maize mandated by different EU countries differ greatly, ranging from 25 to 600 m (Riesgo et al, 2010), even though they share the guidelines on GM foods labeling (EC N • 1829/2003) (Devos et al, 2009).…”

Effect of MON 810 cultivation and prevention to adventitious presence in non-GM fields: A case study in Slovakia

“…Nevertheless pollen grains of maize are large and heavy in comparison with those of other wind-pollinated species and its flight distance is limited to a short range. Taking into account also this characteristic, different isolation distances between the conventional and GM maize and organic and GM maize, respectively, have been adapted in the EU member states (Devos et al 2009). The isolation distances 200 m between the conventional and GM maize and 300 m between the organic and GM maize were adopted in Slovakia and farmers are allowed to replace the mandatory isolation distance by border rows of conventional maize according to the principle: 1 border row can replace 2 m of the isolation distance.…”

Benefits and Costs of Biologically Contained Genetically Modified Tomatoes and Eggplants in Italy and Spain

“…These safety margins differ considerably across EU member states. GM maize, for instance, has a minimum distance requirement ranging from 25 m in Sweden to 800 m in Luxembourg, although scientific evidence does not call for such distances larger than 15-50 m [14].…”

“…One may even question the necessity for coexistence regulations from an economic point of view [12]. The pros and cons have been addressed by a number of authors [1,8,10,11,[13][14][15]. As coexistence requirements are politically motivated, we hardly can expect cultivation of GM tomato and GM eggplants to be possible without coexistence regulations.…”