Have GMO seeds, unknowingly, cross-contaminated with non-GMO crops?

Expert response from Scott Mundell

Senior Compliance Manager, DuPont Pioneer

Friday, 31/01/2014 16:29

The answer to your question depends on the crop. Since soybeans and corn are the two most commonly planted GM crops in the United States, I’ll focus on those crops. Soybeans are nearly 100 percent self-pollinating, so there is little risk of cross-pollination or pollen flow.

For corn, numerous factors impact the likelihood of cross-pollination occurring:

• First, corn pollination occurs during a short, approximately one-week period, and that one-week period would have to overlap between two neighboring fields for there to be any cross-pollination.
• In addition, corn pollen is relatively large and heavy compared with the pollen of other crops, and those attributes limit its movement.
• Local environmental factors, such as natural windblocks, also may impact pollen movement.
• And finally, after corn pollen is shed from the tassel, the viability of that pollen declines rapidly.

Our company’s scientists and independent researchers have been studying corn pollen and its movement and potential flows for more than 80 years. As a result, we know that similar maturities of corn, planted during a similar time frame, in fields that are located close to one another, would have the potential for some low level of cross-pollination. This knowledge about pollen flow helps us attain a high degree of seed purity. For more information, see the DuPont Pioneer 2014 Product Stewardship Guide. A number of university experts have also published information and research about cross-pollination in corn, including Ohio State University and University of California-Davis.