A program control for a carriage reciprocable along rows of fiber bales is mounted on the carriage and includes switch actuating strips which cooperatively reproduce the path of carriage travel. A slide reciprocable relative to the actuating strips is driven by the carriage drive motor for movement corresponding to the carriage movement, but along a path of reduced scale. The slide carries a plurality of switches which are actuated by corresponding strips to effect control of the carriage movement. A clamp carried on the slide is selectively actuated to position switching lugs to control the carriage location relative to the bales in each grade of fiber upon commencement of succeeding fiber-mixing cycles.
