|
|
||||||||
a Monsanto Company, 800 North Lindbergh Blvd, St. Louis, MO 63167 USA
b Monsanto International Sarl, Morges, Switzerland
* Corresponding author (david.i.gustafson{at}monsanto.com)
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.
Abbreviations: AP, adventitious presence of a GM-trait in seed of the receptor field Bt, Bacillus thuringiensis, the soil bacterium source of Cry toxins EXC, expected case gene flow predictions FGM, fraction of pollen assumed to contain a detectable trait of interest GM, genetically modified via transgenic biotechnology techniques PMGF, pollen-mediated gene flow RWC, reasonable worst case gene flow predictions
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Plant Registrations | Soil Science Society of America Journal | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||