Thursday, November 16, 2006 - 9:15 AM

Growth Responses of Bermudagrass and Seashore Paspalum to Sodium Chloride Stress.

Mohammad Pessarakli, Univ. of Arizona, Dept of Plant Sci, "Forbes Bldg, Room 303", "Forbes Bldg, Room 303", Tucson, AZ 85721, United States of America, H. Touchane, Aleppo University, Aleppo, Damascus, Syria, and David Kopec, University of Arizona, Room 303 Bldg 36 Plant sci Dept, Tucson, AZ 85721.

Bermudagrass (Cynodon dactylon L.), cv. Tifway 419 & Seashore Paspalum (Paspalum vaginatum Swartz), cv. Sea Isle 2000 were studied in a greenhouse to evaluate their growth responses in terms of shoot & root lengths, shoot fresh biomass production, & shoot & root dry matter (DM) weights under different levels of NaCl salinity. The grasses were grown hydroponically under four levels of NaCl (Sodium Chloride) salinity treatments, including Control (no salt), 5,000, 10,000, 20,000, & 30,000 mg/l of NaCl in the culture medium. Four replications of each treatment were used in a Randomized Complete Block (RCB) design in this investigation, using Hoagland solution No. 1. The grass shoots (clippings) were harvested weekly, fresh weights were determined. Then, the materials were oven dried at 60o C, & DM weights recorded. Shoot (pre-harvest) & root lengths were also recorded at each harvest. At the last harvest, roots were also harvested, oven dried at 60o C, & DM weights were determined & recorded. The results show that, for both grass species, shoot & root lengths were stimulated at the low levels (5,000 & 10,000 mg/l) of NaCl salinity, but substantially decreased at the high levels (especially, at the highest level, 30,000 mg/l) of NaCl salinity. As the exposure time to salt stress progressed, shoot & root fresh & DM weights were more severely affected than the shoot & root lengths by salinity. These parameters significantly decreased at any levels of NaCl salinity. Bermudagrass was more severely affected than paspalum under any levels of NaCl applications. The above results were observed for both the 4th harvest as well as for the average of all harvests.