Wheat or other granular, flowable material is supplied from a metering hopper at a controlled rate through a limiting aperture at a base of a hopper side wall. A moving surface which has served as a floor of the hopper emerges through the aperture, carrying a covering of material out and toward a material disposal area and is then recirculated into the hopper. The moving surface is a repeatedly used upper surface of a disc or cone that is rotated by a motor. Supply of material is immediately varied by varying the speed of the moving surface.