Comparisons between Press and Pressure Chamber Techniques for Measuring Leaf Water Potential

Abstract

SUMMARYA hydraulic press (the J-14) was compared with a Scholander pressure chamber to measure leaf water potential in Theobroma cacao, Gliricidia maculata, Cajanus cajan and Elaeis guineensis. Although the press satisfactorily estimated water status in soft, unhardened leaves of T. cacao, G. maculata and C. cajan at high water potential, it underestimated water status in hardened leaves of T. cacao. Satisfactory estimates were obtained at low water potential for hardened leaves of T. cacao but not for the others. There was a poor relation between readings of the two instruments for E. guineensis over a wide range of water potentials because press readings appeared to be influenced by leaf structure.