Absorption and Mobility of Foliar Applied Nutrients

The absorption, transport and mobility of foliar applied radioactive isotopes of rubidium, sodium, potassium, phosphorus, chlorine, sulfur, zinc, copper, manganese, iron, molybdenum, calcium, strontium, and barium were determined with the bean as the experimental plant. Using as a criterion the percent of the foliar applied radioactive isotope recovered in non-treated plant parts, and autoradiography to portray gross distribution in the plant it was found that rubidium, sodium and potassium were the most readily absorbed and most highly mobile. Calcium, strontium and barium while absorbed by the leaf were not exported from the leaf and were considered immobile. Phosphorus, chlorine, sulfur, zinc, copper, manganese, iron, and molybdenum were intermediate with decreasing mobility in the order given. Since the preparation of this manuscript, preliminary observations with magnesium (Mg/sup 28/) showed that it was immobile and its distribution following foliar application was the same as Ca/sup 45/, Sr/sup 89/ or BaLa/sup 140/. 22 references, 4 figures, 4 tables.