Proposition 37, which would require labeling on raw or processed food "with genetic material changed in specific ways."

Farmers would see a financial impact from Prop 37, which would require labeling on raw or processed food containing genetically engineered crops, Monsanto spokeswoman Kathy Fairbanks said.

A labeling requirement would impose additional record-keeping costs on farmers, processors and distributors. "These additional costs put them at a competitive disadvantage with competitors in other states, other countries," she said.

Also, she said, consumers' grocery bills could grow by $350 to $400 a year.

California's legislative analyst estimated increased annual state costs ranging from a few hundred thousand dollars to over $1 million to regulate the labeling of GE foods.

There could also be costs to state and local governments due to litigation resulting from possible violations of the requirements of this measure. Some of those costs would be supported by court filing fees that the parties involved in each legal case would be required to pay under existing law.

-- Steve Brown