Selection of black poplars for water use efficiency

Photosynthesis, transpiration, water use efficiency (WUE) and biomass production have been investigated in nine black poplar clones (section Aigeiros) in three field experiments. Eastern cottonwood clones (Populus deltoides) had the highest net photosynthesis and water use efficiency. European black poplar clones had the highest transpiration intensity. Correlation analysis showed that net photosynthesis was in a high positive correlation with biomass. Medium negative correlations existed between WUE and net photosynthesis, transpiration and biomass and WUE and biomass. The study showed a pronounced interclonal variability of the physiological and growth characters under study.