The system is proposed to replace the current practice of manually unbinding and retying tutor ropes for tying plants placed in a vertical position in a greenhouse, in order to lower the plant when it has reached the eave height of the greenhouse, through a dynamic system that allows automatic lowering of the top of said plants by means of quick and easy operations.The system, provided with a modular division, allows, when the plant has reached the height of the eaves, the lowering of each plant or of an entire row of plants by cutting tutor cords or ropes appropriately arranged so permitting the continuation of growth of said culture.It consists of a grid (10), subdivided in turn into a lower grid (8), comprising the vertical tutor ropes (4) of each plant, connected to an upper grid (9) provided with horizontal parallel ropes (3), oblique ropes (5), diagonally connected to each of said horizontal ropes (3) and vertical tape ropes (6), orthogonally connected to each of said horizontal ropes (3). The upper grid (9) forms a dropdown extensible system triggered by cutting said tape ropes (6) and carried out with the rotation of each of said oblique ropes (5) around the respective junction points with the horizontal ropes (3).
