A product management display system for merchandising product on a shelf includes using a trackless pusher mechanism that travels along a surface on which product is placed. A plurality of thin dividers separate the product into rows. The dividers may be formed separately and attached and secured by being inserted into a plurality of grooves arranged along the lower surface and the forward and rear support posts of the product dispensing tray. The dividers are configured to self-adjust by laterally shifting within the grooves when the product is moved forward by the pusher to being loaded by an operator to allow the product to be positioned in a tight fitting manner to maximize the amount of product that can be accommodated horizontally across the tray. In addition, the dividers may have a bottom wall spaced from the surface with a support column that is inserted into an elongated pocket to provide the structural support for the divider.