Food giant Campbell Soup says it will begin to disclose the presence of genetically modified ingredients in its brands, which include Pepperidge Farm, Prego, Plum Organics, V8 and the Campbell’s soups. The move comes as companies grapple with how to comply with a new Vermont law, which requires labeling genetically modified food. The Vermont law passed after fierce opposition from the food industry and is set to take effect in July.