An alternative method for analysing pressure-volume curves produced with the pressure chamber

Abstract. An equation is derived relating tissue water potential to relative water content. This equation may be used to lit a single curve to a set of data such as the standard pressure volume measurements made with a pressure chamber. From such a single curve fitting operation, estimates of the parameters involved may be found, and this allows calculation of such quantities as bulk modulus of elasticity, osmotic potential at full turgor and at the turgor loss point, pressure potential, and the weight of symplastic water. The method of analysis has several advantages, which are illustrated using pressure chamber data obtained from leaves of Lombardy poplar, Populus nigra L. 'italica'.