Empirical Modeling of Genetically Modified Maize Grain Production Practices to Achieve European Union Labeling Thresholds

Abstract

An empirical approach is given for specifying coexistence requirements for genetically modified (GM) maize (Zea mays L.) production, to ensure compliance with the 0.9% labeling threshold for food and feed in the European Union. Field data were considered in which pollen-mediated gene flow (PMGF) was measured within maize receptor fields at a series of distances from source fields having a marker. An empirical model is presented that fits the observed decrease of gene flow with distance. The model was parameterized to provide both reasonable worst case and expected case predictions of gene flow for various combinations of isolation distance, use of non-GM border rows in the GM field and/or separately harvested border rows in the receptor field. Based on the data assessed, the model is used to show that the effect of scale is minimal for source fields of surface area 4 ha and greater. Combinations of isolation distance and border rows of 20 m or more are predicted to result in gene flow of less than 0.9%, as a blended average for receptor fields 1 ha or larger. Lesser requirements are necessary when the source field is much smaller than the receptor, and an extension to the model is provided to estimate such effects.

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.…”

Pollen-mediated gene flow from transgenic safflower (CarthamustinctoriusL.) intended for plant molecular farming to conventional safflower

“…Pollen-mediated gene flow has been quantified in detail in several crops using transgenic and marker genes including wheat (Triticum aestivum L.) (Gustafson et al, 2005;Hucl, 1996;Hucl and Matus-Cadiz, 2001;Matus-Cadiz et al, 2007), oilseed rape (B. napus) (Beckie et al, 2003;Damgaard and Kjellsson, 2005;Rieger et al, 2002;Weekes et al, 2005) and maize (Zea mays L.) (Goggi et al, 2006(Goggi et al, , 2007Gustafson et al, 2006;Weekes et al, 2007) (reviewed in Beckie andHall, 2008). Because of differences in research design and source plot size, studies are difficult to compare directly.…”

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

“…First, by separating the inner parts of neighboring fields, pollen barriers act as an isolation distance, in turn increasing the distance GM pollen has to travel for cross-fertilization. Second, a pollen barrier -if the GM and non-GM crops in question are the same species -introduces competing pollen and/or can serve as a physical barrier to the flow of air and, consequently, the flow of pollen [16,[27][28][29][30][31]. Accordingly, a pollen barrier reduces the extent of cross-fertilization much more effectively than an isolation perimeter of bare ground of the same width [32,33].…”