International Journal of Applied Agricultural Research

Seeds of KW13 cultivar of safflower (Carthamus tinctorius L.) were tested for salt and drought tolerance at germination and early seedling growth in NaCl and PEG-6000 solutions of different osmotic potentials (0, −0.2, −0.4, −0.8, and −1.0 MPa). Daily and final germination, as well as germination and seedling growth were recorded under controlled conditions. Results showed that germination and germination rate were delayed by both solutions, with differences between solutions. PEG-6000 had a lesser effect in terms of germination rate, mean germination time and the final germination and seedling growth than did sodium chloride. This conclusively proves that the adverse effect of sodium chloride on germination, emergence and early seedling growth was due to the specific ion rather than the osmotic effect. Seedling growth was reduced by both stresses, but PEG-6000 usually caused less damage than NaCl to safflower seedlings, suggesting that NaCl and PEG acted through different mechanisms.