Soybean farmers in the U.S., the world’s largest producer of the oilseed, will demand higher premiums for non-genetically modified beans next year and likely only supply the crops under contract, an exporters group said. U.S. farmers are planting fewer acres of non-GMO soybeans that are more expensive to produce and lower-yielding than genetically modified varieties, Dan Duran, chief executive officer of the U.S. Soybean Export Council, said in an interview.