A locking mechanism is provided for a product display tray of the type having a base formed of longitudinal wires and having a product pusher slideable on the wires and urged forwardly by a spring to maintain products at the front of the tray as items are removed by customers. A locking member is positioned to slide on the wires and is pushed forwardly by the spring. The locking member has angled edges which engage the wires when the element is tilted. When the pusher is moved toward the rear of the tray, the geometry of the pusher causes it to tilt the locking member such that its angled edges lock onto the wires, preventing the spring from moving the pusher forward during loading of the tray. Pressing rearward at the top of the pusher reorients the locking member and frees the pusher to be moved forward by the spring.