Pick a pear at the grocery store -- or an apple, tomato or banana, for that matter -- and you'll notice that it wears a little sticker containing a mysterious number such as 4035 or 94035. The numbers on produce are a code that tells if the fruit or vegetable is bioengineered, organically grown or conventionally grown (with pesticides or herbicides).
Here's the key:
A four-digit number means the fruit or vegetable has been conventionally grown using pesticides or herbicides.
An organically grown fruit or vegetable has a five-digit number beginning with 9.
Genetically modified produce has a five-digit number beginning with 8. (There are not many of these around, though. Most bioengineered food is found in processed foods.)
Called "price look-up numbers," or "PLUs," these number codes aren't intended for consumers. Indeed, no official regulatory agency oversees them.
The Produce Marketing Association, an industry trade group, developed the numbering system to provide produce sellers a better way to track inventory and to make sure the price being charged is accurate. (A conventionally grown tomato may look the same as an organic one, but the price usually isn't.)
Stay tuned, however. Those sometimes irritating stickers may be going away. You're likely to soon see produce sporting tattoos rather than stickers. Information laser-imprinted into the skin eliminates the sticker and, some say, allows for better tracking, tracing and protection against bioterrorism.