A Greenpeace activist holds up a cob of black corn during a demonstration outside the Ministry of Agriculture in Mexico City August 19, 2009. Considered by many the cradle of corn, Mexico is home to more than 10,000 varieties, used to make the classic tortilla, a staple of the Mexican diet. Mexico faces the same dilemmas over GM corn as do many developing countries -- balancing consumer fears with the need to grow more food. Picture taken August 19, 2009. To match Special Report FOOD.