Abstract: An agricultural trellis system is provided and generally includes a notch configured to receive a trellis wire therein and selectively release the trellis wire upward during mechanical pruning. The notch can be positioned on an above-ground portion of a vertical line post or a cross arm. The notch can include a tab extending upward from the bottom of the notch, and a first edge and a second edge each formed on the body. The first edge can be a flat edge and can be positioned laterally outwardly from at least a portion of the second edge, which can be a curved edge. The notch can include a retention protrusion extending laterally into the notch toward the second edge to a position where a lateral distance between the retention protrusion and the first edge in a direction normal to the central plane is less than a diameter of the trellis wire.