Use of a Hydraulic Press for Estimation of Leaf Water Potential in Grain Sorghum¹

Abstract

Abstract The hydraulic press (HP) is a highly portable instrument designed for rapid measurement of leaf water potential of plants. This study compared grain sorghum [ Sorghum bicolor (L.) Moench] leaf water potentials measured with a pressure chamber (PC) and using two endpoints with a HP, under glasshouse conditions. The first endpoint is when water exudes from one vein and the second endpoint when water exudes from all veins on both sides of the leaf tissue. The results showed that the HP and PC measurements agreed well in the range of −0.5 to −3.5 MPa of leaf water potentials when the second endpoint was selected for the HP. The HP can be used to measure the leaf water potential of grain sorghum, provided it is calibrated using the second endpoint against a PC or another method.