Fyffes, the Irish banana company trying to merge with Charlotte-based Chiquita Brands International, told investors that the combination could be worth about 60 percent more per share than a rival buyout offer from two Brazilian companies trying to break up the deal. But in a sharply- worded statement Thursday, the Brazilian companies accused Dublin-based Fyffes of trying to "persuade Chiquita shareholders to believe in mythical pot of gold at the end of the rainbow."