http://articles.mercola.com/sites/articles/archive/2009/02/21/Are-Your-Supermarket-Plums-Genetically-Modified--Heres-How-to-Find-Out.aspx/
The little stickers on fruits and vegetables have digits that let you
know whether they're conventionally grown or organic, and if they're
genetically modified (GM). There are many benefits to knowing this
information:
• The health risks -- GM foods have been in stores only since the
1990s, so the long-term health risks are unknown
• The environmental risks -- Scientists are concerned that GMOs will
reduce biodiversity
• The taste benefits -- People all over the world agree that the range
of possible flavors is greater without a few GM foods crowding out the
many natural varieties
Here’s what you should look for:
• A four-digit number means the produce is conventionally grown
• A five-digit number beginning with 9 means it's organic
• A five-digit number beginning with 8 means it's GM