Mexico will decide in October whether it will allow experimental plantings of genetically modified corn, an agriculture ministry official said on Monday. DuPont Co, Dow Chemical and Monsanto have filed applications with the Mexican government for permission to begin testing their genetically modified corn strains. ”At this point we are working to draw up the permit necessary to authorize an experimental planting in the (winter) season,” said Enrique Sanchez, the agriculture ministry’s director of plant and animal health, in an interview.