Picayune (pĭkəyōnˈ) [key], city (1990 pop. 10,633), Pearl River co., S Miss., near the Pearl River and the La. line; inc. 1904. It is the trade, processing, and shipping center for an agricultural area with cotton, corn, pecans, cattle, and dairying. Manufactures include elevators, chemicals, polyurethane, metal containers, and computer equipment. NASA's Stennis Space Center and the Crosby Arboretum are nearby.