Growth Responses of Various Cultivars of Seashore Paspalum to Salinity Stress.

Various Seashore paspalum (Paspalum vaginatum Swartz) cultivars (Aloha, Sea Dwarf, Sea Isle 1, Sea Isle 2000, UG22, and Salam) were studied in a greenhouse to evaluate their growth responses in terms of shoot and root lengths, shoot (clippings) fresh and DM weights and the grass general quality under salinity stress conditions. Grasses were grown hydroponically using Hoagland solution No. 1 salinized with Instant Ocean salt to EC levels of 10, 20, and 30 dSm^-1. Four replications of each cultivar and each salinity treatment and the control were used in a RCB design in this study. Grasses were grown at each salinity level for a week, then the grass shoots were harvested. Prior to each harvest, shoot and root lengths were measured and recorded, and grass general quality was also evaluated. The harvested clippings fresh weights were weighed and recorded. The clippings were then oven-dried at 65° C and DM weights recorded. At the last harvest, roots were also harvested and fresh weights determined, then oven-dried at 65°C and DM weights were recorded. The results showed shoot and root lengths and clippings fresh and DM weights of all the cultivars decreased only at the highest level of salinity (30 dSm^-1). Compared with the control (unsalinized) treatment, the lower level of salinity (10 dSm^-1) slightly enhanced these growth parameters. At each salinity level, there were some numerical differences found in the shoot and root lengths and/or clippings and roots fresh and DM weights of the various cultivars. For all the cultivars, under all levels of salinity, the root length was less severely affected than the shoot length. No significant differences were found in grass general qualities under various salinity levels. Based on the results of this study, all the cultivars exhibited true halophytic characteristics, showed a high level of salinity stress tolerance.