Effects of drought stress on biomass, several growth parameters and water use efficiency of eucalyptus (Eucalyptus camaldulensis Dehnh) in response to drought stress.

Biomass production, shoot, root, leaf, root to shoot ratio (R/S), specific leaf area (SLA) and water use efficiency (WUE) of eucalyptus (Eucalyptus camaldulensis Dehnh) were investigated under three different soil water regimes, 100%, 70% and 40% of field capacity (FC). The research was conducted based on a complete randomized design with 3 replications under lysimetery and natural conditions in an arid region. The experiment was carried out during 2006-2008 at Shahid Sadouqi Desert Research station of Yazd. Results showed that biomass production, shoot, root, leaf, root to shoot ratio and shoot to life ratio decreased significantly with reduction in soil water content. Specific leaf area increased significantly with reduction of soil water content. Water use efficiency increased significantly with reduction of soil water content but was not significant between 70% and 40% field capacity treatments. Regarding wood production, water use efficiency increased significantly for 70% field capacity treatment, compared to other treatment.