• Drought Tolerance of Twenty one Saltgrass (Distichlis) Accessions Compared to Bermudagrass

      Pessarakli, Mohammed; Marcum, K. B.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Fourteen (14) Arizona accessions and 7 Colorado accessions of Saltgrass (Distichlis spicata), collected from Arizona and Colorado and 1 Bermudagrass (Cynodon dactylon), cultivar Midiron (check), were studied in a greenhouse to evaluate their growth responses in terms of shoot dry weights and percentage of visual green under drought stress conditions. Plants were grown under normal (daily watering and weekly fertilizer application) for one year for complete establishment. Then, the plants were deprived from water for four months (January 5, 2001 - May 5, 2001). Plant clippings were harvested weekly, oven dried at 60 °C, and the dry weights were recorded. At each harvest, percentage of green cover were also estimated and recorded. After the last harvest, plants were re-watered to assess and compare the percent of recovery. Overall, the results (both shoot dry weights and the percent of the visual green) show that the A138 and A137 (Arizona accessions) were the best accessions and the C66 (Colorado accession) was the worst. Both the shoot dry weights and the percent of visual green cover decreased as the drought period progressed. In general, most of the saltgrass accessions were more tolerant to drought stress than the bermudagrass.
    • Growth Responses of Desert Saltgrass under Salt Stress

      Pessarakli, Mohammed; Marcum, K. B.; Kopec, David M.; Kopec, David M. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001-09)
      Saltgrass (Distichlis spicata), clonal accession WA-12, collected from Wilcox, Arizona was studied in a greenhouse to evaluate its growth responses in terms of shoot and root lengths, shoot fresh weight, and shoot and root dry weights under control and salt (sodium chloride) stress conditions. Plants were grown under control (no salt) and three levels of salt stress (100, 200, and 400mM NaCl equivalent to 6250, 12500, and 25,000 g Lᴮ¹ sodium chloride, respectively), using Hoagland solution in a hydroponics system. Plant shoots (clippings) were harvested weekly, oven dried at 60 °C, and dry weights recorded. At each harvest, both shoot and root lengths were measured and recorded. At the last harvest, plant roots were also harvested, oven dried, and dry weights were determined and recorded. The results show that the shoot and root lengths decreased with increasing the salinity levels, however, both shoot fresh and dry weights significantly increased at 200mM NaCl salinity compared with the control or the 400mM NaCl level. Root dry weights at both 200mM and 400mM NaCl salinity levels were significantly higher than the control.