Abstract
Four cotton cultivars differing in tolerance to stressed conditions were grown in solution culture at salt concentrations of 75,150 mol m -3 and control. The K+ /Na+ ratios of 1:1, 1:2.5, 1:5,1:10 and 1:20 were maintained at each salinity level. At salt stress of 75 mol m-3 , the K+ / Na+ ratios of 1:2.5 and 1:20 produced significantly (P ≤0.05) higher fresh matter yield as compared to other ratios. At salt stress of 150 mol m-3 , the yield differences due to external K+ / Na+ ratios were non significant. Higher shoot growth reduction was found at K+ / Na+ of 1:1 in both salinity levels. It is concluded that the K+ : Na+ ratio of 1:2.5 (low salinity) and 1:10 (high salinity) had least inhibitory effect on the growth of cotton cultivars as compared to all other K+ / Na+ ratios. Performance of NIAB 78 and MNH 93 was superior to Ravi and D 9.
