THE USE OF FRITTED TRACE ELEMENTS IN PEAT-SAND SUBSTRATES
Problems encountered during minor element studies by the release of minerals from the walls of clay pots are well known, and Badger and Bray (1) suggested the use of glass of low solubility to give a controlled supply of minor elements. The desired minor elements are mixed with silicates, fused by heating to 1, 000°C, quenched in cold water and then ground to a fine powder. The product is known as a fritted trace element mixture, and in this form has a much lower solubility than the original inorganic salts, thereby giving a release over a long period and at the same time providing a greater margin of safety against phytotoxicity. Preliminary work had shown that the use of a general purpose frit containing boron, copper, iron, manganese, molybdenum and zinc corrected boron deficiency in pot chrysanthemums (Bunt, 2), but subsequent work indicated that it might be desirable to vary the rate of frit with the form of nitrogen used. Further work was, therefore, undertaken to investigate those factors which could interact with the use of fritted trace elements in pot plant substrates.