A longitudinally adjustable flow divider situated in the particulate material path of a spinner spreader between the bin and the rotatable disc divides the particulate material so that the particulate material is dischargeable on to the upper surface of the rotatable disc on first and second laterally spaced apart longitudinally oriented drop lines. An actuator operably connected to the flow divider adjusts a longitudinal position of the flow divider to longitudinally adjust drop points on the drop lines at which the particulate material is dischargeable on to the rotatable disc. Longitudinal adjustment of the drop points along laterally spaced apart drop lines on one spinner disc permits control over spread pattern to help achieve uniform distribution of the particulate material on a ground surface.