Abstract
Three sorghum [Sorghum bicolor (L.) Moench.] cultivars namely Mr. Buster, Honey Graze and Extra Sweet of Australian origin were tested for their salinity tolerance. Their germination was assayed against a series of NaCl concentrations (0, 100, 200, 300, 400, and 500 mM NaCl) in Petri plates. Seedling growth was tested in a sand culture experiment in pots under saline irrigation with 50, 100, and 150 mM NaCl prepared in half strength Hoagland solution. Germination of all cultivars was inhibited as a direct function of salinity. Salinity reduced the germination velocity relatively in higher magnitude in case of CV. Honey Graze. Fifty per cent reduction in final germination corresponded with 421.57, 335.57 and 327.46 mM NaCl in CV Mr. Buster, CV Extra Sweet and CV Honey Graze., respectively. The parameters like seedling phytomass, number of leaves per plant and total leaf area per plant declined with salinity. Fifty per cent reduction in growth, in terms of dry weight of seedling phytomass, corresponded with 82.9, 82.1, and 72.7 mM NaCl in CV Extra Sweet, CV Honey Graze and CV Mr. Buster, respectively. Obviously, sorghum appeared to be more tolerant at germination phase. Growth phase is more susceptible to the salinity in the root zone. Salt tolerance sequence, on the basis of 50 % germination loss over control, of the cultivars in hand was – Cv. Mr. Buster > CV Extra Sweet > CV. Honey Graze. Salt tolerance sequence, on the basis of 50 % loss of seedling phytomass over control, of the cultivars in hand was- Cv. Honey Graze ≈ CV Extra Sweet > CV. Mr. Buster
