The effects of calcium and boron on apple trees when applied through microjet irrigation

Two experiments were performed to study the effects of calcium (Ca) and boron (B) applied as calcium chloride {CaCl₂*2H₂0(27% Ca)} and Solubor {Na₂B₄0₇(20% B)} through microjet irrigation to young apple trees (Malus domestica Borkh). The effects of CaCl₂ and Solubor treatments on both soil and foliar nutrient levels were measured when Ca and B were applied in irrigation water with and without foliar applications of Ca as CaCl₂ (Exp 1). Additionally, the effects of Ca and B fertilization with and without irrigation were investigated (Exp 2). No differences in foliar or soil test extractable Ca concen-trations were found with any CaCl₂ treatments for either experiment. Treatments providing 0.25 and 0.50 g/day/tree Solubor (1982) and 0.50 and 0.10 g/day/tree of Solubor (1983) significantly increased both soil and foliar B levels (Exp 1). Applications of 0.50 g/day/tree of Solubor in experiment 2 increased the levels of B in the soil but not in the leaves. No differences were found between the irrigated and non-irrigated treatments. The addition of CaCl₂ to irrigation water did not influence volume output but did influence the irriga-tion spray pattern.