Growth Responses of Sacaton Grass (Sporobolus airoides Torr.) and Seashore Paspalum (Paspalum Vaginatum Swartz) Under Prolonged Drought Stress Condition.

Climate change due to global warming and shortage of water mandates use of low quality waters for irrigation and cultivation of plant species with high degrees of drought tolerance. Thus, there is an urgent need for finding drought tolerant plant species to survive under dry arid regions. Our preliminary investigations indicated that halophytic grass species have a great potential to be used under harsh and stressful arid conditions. Therefore, alkali sacaton (Sporobolus airoides Torr.) and paspalum (Paspalum Vaginatum Swartz), halophytic grass species, were studied in a greenhouse to evaluate their growth responses under prolonged drought stress. Four replications of each grass species were used in a RCB design trial. Plant shoots were harvested weekly, oven dried at 70 ^oC, and dry weights recorded. At each harvest, shoot length was measured and recorded and the grasses’ general qualities were estimated. Results showed at all weekly measurements, shoot height of sacaton grass was substantially higher than that of seashore paspalum under drought stress. In contrast, compared with the sacaton grass, both shoot fresh and dry weights of seashore paspalum were significantly higher than that of sacaton grass. The shoot fresh and dry weights of both grasses decreased as drought stress progressed. The shoot succulence of both grasses followed the shoot fresh and dry weights. At the early evaluations, general quality of seashore paspalum was substantially better than that of sacaton grass. However, as the drought period progressed, this trend was reversed and the quality scores of the sacaton grass were higher than that of seashor paspalum. The qualities of both grasses decreased as drought stress progressed. At later evaluations, these parameters were not acceptable for either of the grasses (unacceptable quality scores of <6), slightly higher for sacaton grass than for seashore paspalum. Both grass species had a satisfactory growth under drought stress. This indicates that these grasses can successfully and effectively be used as cover plant species to prevent soil erosion and combat desertification under dry arid regions.