Abstract: An air divider having a shutoff plate for converting row spacing on a seeding implement. A reversible shutoff plate has a closed position wherein one end of the plate extends through a slot and completely blocks a leg of a Y-shaped output end of the divider. By reversing the shutoff plate, the leg is opened to air and material flow. The shutoff plate is retained in a clip or post adjacent the slot in both the closed and open positions. A seal closes the slot if the shutoff plate is not inserted and permits the shutoff plate option to be selected at any time.