EN
In this work the energetics of water transport along the radial path of bean root (Phaseolus vulgaris L) and water elevation along the xylem induced by osmotically generated root pressure was studied. The radial path of the root was, according to Fiscus's concept [1,2], approximately modelled by a 1-membrane system. An analytical method by Kargol [5] (concerning the osmo-diffusive conversion of free energy) and data from a work by Steudle [9] (on permeation parameters of the root, i.e., filtration coefficient Lp, reflection coefficient a and permeability coefficient co) were applied in this study. This work shows that the energetical efficiency of the root of that plant does not depend on concentration, C0 of the root bathing solution (the medium) within the concentration range: 0