Departments of Plant Sciences and Chemistry, Sultan Qaboos University, P.O. Box 34, Al Khod 123, Sultanate of Oman.
Seedlings of five tomato cultivars were transplanted to sand culture irrigated with half strength Hoagland solution (control), 50 mM NaCl and 50 mM NaCl + 2 mM KNO3. Biomass yield of the various tomato cultivars was markedly reduced when 50mM NaCl was used in irrigation. The magnitude of weight reduction was substantially decreased in all cultivars with the incorporation of K in the saline regime. Tomato roots have accumulated more Na than in leaves. Relative to control plants, the amount of Na was increased in roots and leaves when K was employed with NaCl. The content of K in tomato roots was decreased under salinity, but increased when K was added to the saline media. Higher levels of leaf potassium were obtained in all tomato cultivars, with Kinirrigation water. Potassium content in cvs. Pearson and Monte Carlo when received 2mM K, was 5-fold greater than under control and was 3-fold and 10-fold higher than under NaCl stress.
