CHELATION OF TRACE METALS IN NUTRIENT SOLUTIONS

Abstract

Germination and seedling growth studies with tomato, pea, bean, corn, and radish, and water culture tests with tomatoes, using various concns. of chelating agents are described. Chelating chemicals used were: 8-hydroxyquinoline (oxine), Na diethyl-dithiocarbamate (carbamate), Na 1,8 dihydroxynaphthalene 3,6 disulfonate (chromatropic salt), Na l-nitroso-2-naphthol 3,6 disulfonate (nitroso-R-salt), tetrahydroxyanthraquinone (quinalizarin), and hydroxy-benzoic acid (salicylic acid). Iron was the only metal ion effectively removed from soln. at low concns. of oxine, carbamate, nitroso-R-salt, and quinalizarin. Iron was not effectively chelated by either chromatropic salt or salicylic acid. Concns. of chelating agents in which plants would grow did not chelate metal ions effectively, while concns. of chelating agents which chelated effectively produced severe plant injury. This injury resulted from heavy metals being extracted from the root cells.