Vol. 1, Issue 2, Part A (2019)

Rice is grown on about one-tenth of the earth’s arable land. It is the single largest source of food energy to more than half of the world population. Salinity confines the efficiency of production at the mature stage. Soil salinity decreases the plant growth rate and can harshly limit the crop production. Salinity tolerance differs extensively between species of plants and within species A pot study was conducted to evaluate the salt tolerance of rice varieties under different salinity cum sodicity levels [S₀=2.70dSm^-1+ 11.38 (mmol L^-1)^1/2, S₁= 5.16dSm^-1 +27.88 (mmol L^-1)^1/2, S₂= 6.15 dSm^-1 +30.38 (mmol L^-1)^1/2 and S₃= 6.78 dSm^-1 +33.74 (mmol L^-1)^1/2 ]. Seeds of seven rice varieties namely PB-95, SRI-12, T-05, No 1121, SRI-13, Basmati-515 and Shaheen Basmati were used for screening against salt tolerance in pots with different salinity cum sodicity combinations at green house of Land Resources Research Institute, National Agricultural Research Centre, Islamabad, Pakistan during, 2017. Completely randomized deign was applied with three repeats. Data on grain yield were collected. This study showed significant differences in grain yield with seven rice varieties. At S₀ [2.40dSm^-1+ 11.38 (mmol L^-1)^1/2] Basmati-515 rice variety gained the top position in grain yield (4.18 tha^-1) and the lowest position was attained by T-05 with grain yield (3.41 tha^-1). PB-95 produced the highest paddy yield (3.18tha^-1) and Shaheen Basmati attained grain yield (3.06tha^-1). All other rice under S₁ [5.106dSm^-1+27.88 (mmol L^-1)^1/2] showed the lowest grain yield. Under S₂ [6.15dSm^-1 +30.38 (mmol L^-1)^1/2] PB-95 rice variety attained the highest grain yield (2.16 tha^-1). Rice line 1121 also received the least position (1.66tha^-1) in this salinity level. % decrease at S₂ over S₀ was indicated salt tolerance of rice varieties. PB-95 rice variety attained the lowest % decrease at S₂ over S₀ (45.17). PB-95 rice variety attained the highest grain yield (1.08tha^-1) at S₃ [6.78dSm^-1 +33.74 (mmol L^-1)^1/2]. Rice line 1121 also received the least position (0.62tha^-1) in this salinity level. % decrease at S₃ over S₀ was indicated salt tolerance of rice varieties. PB-95 rice variety attained the lowest % decrease at S₃ over S₀ (72.58). Therefore, this variety had the maximum salt tolerance than other rice varieties under this experiment.