Implementing isolation perimeters around genetically modified maize fields

Abstract

-Due to the growing cultivation area of genetically modified (GM) maize and the rising number of GM maize varieties commercially available to European farmers, the co-existence between GM and non-GM maize is becoming a burning issue in some European regions. Hence, Member States are imposing or discussing specific co-existence measures to keep the adventitious presence of GM material in non-GM produces below the established labelling threshold. As maize is a cross-pollinated crop that uses wind for the dispersal of its pollen, on-farm co-existence measures may rely on the spatial isolation of GM and non-GM maize fields. In this study, we developed an approach that combines geographic information system (GIS) datasets with Monte Carlo simulations to assess the feasibility of implementing isolation perimeters around GM maize fields, since its practical implementation is rarely addressed in the co-existence debate. More specifically, five scenarios differing in shares and spatial distributions of GM maize were tested for various isolation perimeters in two agricultural areas in Flanders (Belgium). The GIS analyses emphasised the small size of maize fields and their scattered distribution throughout the cropped area. The feasibility of implementing isolation perimeters was largely affected by the (GM) maize share, the spatial distribution of GM maize, and the width of isolation perimeters. The higher the (GM) maize share and the wider the isolation perimeter, the higher the proportions of farmers with non-GM maize fields occurring within the implemented isolation perimeter. Compared with randomly distributed GM maize fields, the clustering of GM maize fields on a larger scale and at the farm level increased the feasibility of implementing isolation perimeters. The approach developed proved to be a valuable tool to quantify the feasibility of implementing isolation perimeters under real agricultural conditions. adventitious mixing / co-existence / cross-fertilisation / genetically modified crops / geographic information system / isolation perimeters / pollen flow / regional variation / simulations

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

“…Van de Wiel et al (2009) in the field trials in the Netherlands concluded that the grain admixtures as a consequence of pollen mediated gene transfer from GM maize were much lower: 0.080-0.084% at 25 m and 0.005-0.007% at 250 m, respectively. Our results contributed to and confirmed several previous conclusions as published by Gustafson et al (2006), Messean et al (2006), Devos et al (2007), and Sandivo et al (2008) who observed that the maize pollen grains flow and pollen mediated gene transfer decline rapidly with increased distance. These studies do also draw the attention to the impact of the isolation distances for the implementation, as well as to the negative impact on the feasibility and production cost if disproportionate measures should be implemented.…”

Regulating coexistence of GM and non-GM crops without jeopardizing economic incentives

“…In scientific and regulatory communities, the debate about coexistence has been centered mainly on the following aspects: preventive coexistence measures needed to keep the adventitious presence of GM material in non-GM products below established tolerance thresholds [5,[7][8][9][10][15][16][17][18]; the feasibility and costs of implementing such measures [16,[19][20][21][22][23]; segregation costs and potential economic losses resulting from adventitiously co-mingled products [24][25][26]; who should bear the costs of coexistence measures [2,14]; and who should redress the incurred economic losses due to adventitious mixing [13]. Although these aspects are of fundamental importance when discussing coexistence strategies, they do not take into account the economic incentives for coexistence.…”

Assessment of regional capabilities for agricultural coexistence with genetically modified maize

“…In dieser Arbeit wird eine Methode dargestellt, und deren Ergebnisse mit anderen Arbeiten verglichen [1][2], mit der die räumliche Verteilung von Maisanbauflächen, auch von GV-Sorten, in einer Region simuliert werden kann. Die Ergebnisse können zunächst Aussagen darüber liefern, in welchem Umfang das räumliche Nebeneinander von Nicht-GV-Mais und GV-Mais in einer Region möglich und in welchen Gebieten Koexistenz problematisch ist.…”