Scale Implications for Environmental Risk Assessment and Monitoring of the Cultivation of Genetically Modified Herbicide-Resistant Sugar Beet: A Review

Abstract

Genetically modified herbicide-resistant (GMHR) sugar beet (Beta vulgaris L.) has been cultivated in the US for several years and an application has been submitted for cultivation in Europe. Concerns have been raised about how GMHR sugar beet cultivation might impair the agro-environment.

European legislation for GM plants requires, prior to their commercial import and/or cultivation, a stepwise reduction of the containment and a gradual increase in the scale of release. Experimental results gained during this procedure enter an environmental risk assessment; after the GM plant approval, a systematic monitoring of potential adverse environmental effects is required.

We collected information on sugar beet biology and cultivation and the HR technology. We categorised the literature findings, evaluated the evidence of agro-environmental effects and indicated adverse effects. The impacts are directly and indirectly linked to sugar beet biology and/or to the HR technology. Most likely are a) adverse herbicide effects on field organisms, aquatic communities and soil microbial communities, b) persistence of the GM plant triggered by a potential selective advantage and/or genetic drift after hybridisation of GMHR cultivated, feral and weed beet with neighbouring beets and wild relatives, c) the increase of HR in weeds and subsequent increase and/or change in the herbicide application regime after several years of glyphosate application, and d) decline in agrobiodiversity (weed communities, herbivores, pollinators and beneficial species).

Our study reveals a lack of experimental data on potential agro-environmental effects. This suggests that the principle of a stepwise scale increase of release is inadequately applied to the GMHR sugar beet approval process. The adverse effects identified should prompt further research experiments to gain information for the ERA and/or specific monitoring activities at the respective identified spatial scale levels.