Salt Tolerance of Six Switchgrass Varieties

Panicum virgatum (switchgrass) varieties were evaluated for salt tolerance in a greenhouse setting. Switchgrass ‘Cimarron’, ‘NL 94C2-3’, ‘NSL 2009-1’, ‘NSL 2009-2’ , ‘Kanlow’, and  ‘Alamo’, five seedlings per pot, were irrigated with nutrient solution at electrical conductivity (EC) of 1.2 dS·m^-1 (control) or salt solution at EC of 5.0 or 10.0 dS·m^-1 for 36 days. Plant height, leaf area,  number of tillers, and dry weight were significantly different among salt treatments and among varieties, but no interactive effects occurred . Compared to control, salt solution at EC of 5.0 dS·m^-1 and 10.0 dS·m^-1 reduced the switchgrass height by 6.8% and 29.6%, leaf area by 20.8% and 55.9%, number of tillers by 14.6% and 31.3%, dry weight by 23.1% and 55.7%, respectively. Switchgrass ‘Alamo’, ‘Kanlow’, and ‘NSL 2009-2’ were taller than ‘NL94C2-3’, ‘NSL 2009-1’,  and ‘Cimarron’. Tiller numbers in ‘NSL 2009-2’ and ‘NSL 2009-1’ were similar to those in ‘NL94C2-3’ and ‘Cimarron’, while higher  than  those in ‘Alamo’ and ‘Kanlow’. The dry weight of ‘NSL 2009-2’ was similar to that of ‘NSL 2009-1’ and ‘Kanlow’, but greater than that of ‘NL94C2-3’ and ‘Alamo’. ‘Cimarron’ had the smallest dry weight. In conclusion, salinity negatively affected the switchgrass biomass, and  switchgrass ‘NSL 2009-2’ and ‘NSL 2009-1’ were more tolerant to salt than other tested varieties.