The main effects and interactions of foliar applications of MnSO₄, ZnSO₄, and urea in factorial combinations on nutrients in Valencia orange leaves were studied. The presence of MnSO₄ in ZnSO₄ foliar sprays containing Na₂CO₃ as precipitating agent significantly decreased the concentration of soluble Zn ions in solution and, as a consequence, decreased the concentration of Zn in the leaves as compared with Zn concentration found in the spray solutions and leaves of trees sprayed with ZnSO₄ alone. The presence of ZnSO₄ plus Na₂CO₃ in MnSO₄-urea foliar sprays significantly increased the concentration of soluble Mn ions in solution, causing increased Mn concentration in the leaves of trees sprayed with this solution. Considering all Mn-urea treatments in this experiment, a positive interaction between Mn and urea foliar applications occurred: Mn concentration increased in the leaves of trees sprayed with MnSO₄-urea mixture. This increase in Mn concentration in the leaves may have been due to better uptake of Mn by the leaves when urea was present, since the concentration of Mn in the spray solution was not affected significantly by the presence or absence of urea in Mn foliar sprays.