Tesco has broken ranks with the major supermarket groups by imposing a ban on crops grown in fields that have been host to genetically modified foods. It said the decision would not affect its current suppliers but will help them plan their future farming cycles. The ban applies to field vegetables and outdoor salad crops which were grown on land within one year of GM crops. According to Tesco, the decision was made following customer concern about genetic material left in the soil by GM crops that could potentially contaminate new crops. {{NEWS }}