Nigeria, Oct. 30 -- As the afternoon sun settled over the city of Bichi in Kano State, Hauwa Saminu untied the sack of maize she had bought earlier that day at a neighbourhood market.

The purchase was routine. She had examined the grains carefully before choosing the cleanest ones and bargaining with the sellers. The maize would later be taken to a nearby milling shop, then cooked at home into tuwo, a staple meal her 12-member household eats for dinner, usually paired with Miyan kuka (Baobab soup), and often again the following morning.

She had no idea whether what she bought was the conventional maize she had eaten for years or Nigeria's new genetically modified maize.

"I always buy maize. Nobody has ever told me whether it is TELA ma...