Effect of Soil Water Deficit on Growth and Water Use Efficiency for Three Tunisian Pastorals Species (Lotus creticus, Plantago albicans and Rhanterium suaveolens)

Three pastorals species (Lotus creticus, Plantago albicans and Rhanterium suaveolens) were subjected to two watering regimes (50 % and 100 % of field capacity (FC)). The aim of the current work is to study the effect of water deficit on growth parameters (leaf area, leaf elongation and biomass production) and water use efficiency of the studied species during two growth stages: seedling or establishment stage and full vegetative stage. We noted that water stress induced a reduction of all studied parameters mainly in the second stage. The highest decreases in leaf area (50.00%) and in leaf elongation were shown in Plantago albicans. However, we noted an increase of water use efficiency on all studied species; Rhanterium suaveolens used more efficiently water (52.37%) in stress conditions than Lotus creticus (11.77%) and Plantago albicans (3.62%).