Greenpeace demanded Thursday that Mexico ban the planting of genetically modified corn, using a giant ear of corn covered with a condom to dramatize the idea of protecting native crops. Greenpeace activists protested against GM crops in front of the Agriculture and Ranching Secretariat in Mexico City. The group said that the Mexican grain can only be protected from contamination with a solid ”regime of special protection for corn” and criticized those who support the experimental sowing of GM corn in Mexico.