Seed and chemical giants Bayer and Monsanto said Wednesday that they will merge to become one of the world’s biggest agriculture giants, a $66 billion mega-deal that could reshape the future of farming and enhance their influence over the planet’s food supply. Bayer said it will spearhead the largest all-cash buyout in history in hopes of taking over St. Louis-based Monsanto, the world’s largest supplier of genetically modified seeds. The merger marks one of the most prominent signs yet of the broadening acceptance of genetically modified foods. The deal would also further strengthen the companies’ grips on vital seeds, pesticides and farm technologies, a concerning turn that critics said could raise prices, reduce choice and stifle innovations needed to feed a growing world. More