Abstract
In long-term experiments with differentially salinized nutrient solutions, plants of Lycopersicon esculentum Mill cv. Walter failed at Na+ concentrations of 200 millimolar or more but tolerated K+ concentrations of that magnitude. The behavior of the wild, salt-tolerant Lycopersicon cheesmanii (Hook) C. H. Mull., accession number 1401, was diametrically different; it tolerated Na+ at 200 millimolar, but K+ at the same concentration proved toxic to it.