Dear Juzhi Hou Quantitative measurements of water use efficiency is routinely done by gravimetric approach that involves regular weighing of the containers to determine the water transpired over a period of time and the biomass accumulated by the plants during this time. Gas exchnage measurements using IRGA are also used for a rapid determination of WUE at a single leaf level. We have these data for a number of crop species. Our recent experiments with rice will be published in Crop Science soon. Numerous publications from Prof. Graham Farquhar, Richard Richards, Tony Condon and others should give you the requisite details. hope this helps Shesha Dr. M.S. Sheshshayee Assistant Professor Department of Crop Physiology University of Agricultural Sciences GKVK Campus, Bangalore 560 065 INDIA Ph(W): +91-80-2362 0737 Ph(H): +91-80-2363 6414 Mobile: 93419 04877 >From: Juzhi Hou <[log in to unmask]> >Reply-To: Stable Isotope Geochemistry <[log in to unmask]> >To: [log in to unmask] >Subject: [ISOGEOCHEM] water use efficiengy >Date: Mon, 3 Oct 2005 09:57:05 -0400 > >Hi Dear List members, >Are there quantitative or semi-quantitative measurments of water use >efficiency of different plants? >Thanks a lot for help! >Juzhi Hou