evaluation of salinity tolerance of forage sorghum varieties with stress tolerance and susceptibility indices

the objective of this study was evaluation of salt tolerance of elite forage sorghum lines in laboratory and field conditions. salinity treatments were 5, 10, 15, 20, 25, 30 decisimens per meter in laboratory and distilled water as control. lines were kfs1, kfs2, kfs3, kfs4, mfs1, mfs2 and lfs56. the lines also cultivated in saline and non saline field conditions during 2004-2005. electrical conductivity of irrigation water was 2 and 11 decisimens per meter in non saline and saline conditions. results showed that t50 (days until 50% germination) increased as salinity increased. the salinity threshold value at germination stage regardless to lines was 8.37 ds.m-1 with slop of 1.6%. upon field experiment, the kfs2 line produced the maximum of 77.25 ton.ha-1 fodder yield in non saline condition, followed by kfs3 and kfs4 lines. the kfs3 line also produced the maximum fodder yield of 55.63 ton.ha-1 in saline condition. total fodder yield of kfs2 line was 49.44 ton.ha-1 in this condition. at all, kfs3 and kfs3 are the sustainable lines on upon of susceptible and tolerant indices.