Effect of water stress imposed at vegetative stage on growth and physiological traits of subterranean clover

Pasture productivity in the Mediterranean region depends mainly on the soil water deficit. Subterranean clover originates from the Mediterranean region and is adapted to areas with hot and dry summers. The response of Subclover to drought was studied in greenhouse and subjected to three soils - water levels: 100% (control), 50 and 25% of field capacity (FC). After 70 days of water deficit treatment, our results showed that increasing levels of water constraint resulted in a progressive decline in the different growth parameters (shoot and root dry matter (DM) height, leaf area, shoot and root (DM)) and those of water content and leaf chlorophyll concentration. At the limited irrigation, Trifolium subterraneum L. showed smaller decreases in plant height and leaf area. Despite, limited irrigation increased the root to shoot ratio of DM. Thus, it shows better adaptation and a more balanced water balance. Findings of this study suggest that subterranean clover used avoidance mechanisms to withstand drought.