Study of Eucalyptus (E.camaldulensis) Water Requirement With Lysimetric Experiments.

The water consumption characteristics and the effects of drought stress on morphological and physiological of Eucalyptus (E. camaldulensis) were investigated under the natural condition whit drainage and weighting lysimeters in Yazd Shahidsadoge control desert research station. The experiment carryout with three different soil water regimes, which were 100% (control), 70% (moderate stress) and 40% (high stress) of field capacity (FC), respectively. All experiments were conducted in a completely randomized design with three replications. Results indicated that E. camaldulensis have a high water use potential and increasing of soil moisture cause for increase of evapotranspiration. The crop coefficient (Kc) measured 1.75 in control treatment. The morphological factors such as: shoot dry mass, root dry mass, trunk cross sectioinal area, leaf area index (LAI), root to shoot ratio (R/S) were detected under watering regimes and have significant differences (P 0.001). the number and size of stomatal not significant differences (P 0.05) under water regimes. The physiological behavior such as: water use efficiency (WUE), leaf water potential, leaf osmotic potential, leaf torgur pressure, relative water content (RWC), leaf soluble sugar, specific leaf area and relative chlorophyll content (RCC) were followed in well watered and drought stressed plants. Increasing of soil moisture not significant differences in root soluble sugar and leaf prolin. Water use efficiency (P 0.001), leaf torgur pressure (P 0.001), relative water content (P 0.001), relative chlorophyll content (P 0.001) increasing with increase of soil moisture and leaf water potential (P 0.001), leaf osmotic potential (P 0.001), leaf soluble sugar (P 0.001) and specific leaf area (P 0.001) decreasing with increase of soil moisture.