Concentrations of aconltate, citrate, total organic acids, K, Ca, Hg, and total cations were measured and found to vary in corn (Zea mays L.) roots, sheaths, stalks, tassels, husks, cobs, kernels, and leaves, depending on plant part, leaf position, and growth stage. Aconitate constituted about half of the total organic acids in above-root plant parts, except kernels. Aconltate did not accumulate in mature kernels. Overall, aconltate made up 18% of the total acids in roots. About 4% of the total organic acids in most plant parts vas citrate with concentrations highest in tassels and kernels. Correlations were higher between aconitate and K as compared with Ca and Mg, and between citrate and Ca as conpared with Mg and K.INTRODUCTION .