A support device, or hook, for removably securing movable wires on a row of plants, such as for example a vineyard or an orchard, on a support pole. In particular, the support device is made up of an elastically deformable filiform body, shaped in such a manner as to have at least engagement elements adapted to elastically cooperate with an opening provided on the support pole to removably secure the support device on the support pole, and support elements, adapted to elastically cooperate with the external surface of the support pole to removably receive the wire, wherein the engagement elements and the support elements are formed by portions of the filiform body lying on planes essentially orthogonal to each other.