An agricultural row marker assembly is provided which includes a three-piece articulated arm and which is hydraulically actuated. The assembly has a base which is connectable to an agricultural tool bar. A second arm is pivotally mounted to the first arm and a telescopingly extendable third arm is pivotally connected to the second arm. A marker disc is located at the distal end of the third arm. The arm is hydraulically actuated with the hydraulic cylinder acting on the first arm through a link member. A second link runs from the base to the second arm and a cable runs between the second link and the third arm so that extension of the hydraulic cylinders extendable rod urges all three arms in the substantially linear alignment.