Mexico this week temporarily stopped shipments of U.S. rice at the border and asked that future loads be certified "GMO Free," according to Dow Jones (subscription required). Two shipments were held up at the border, although they were eventually released and allowed to enter Mexico after the USDA intervened.
The USDA last week told rice farmers not to plant a variety of conventional rice that was contaminated with unapproved genetically modified material. Previous cases of contamination have shut down U.S. rice exports to other nations.