The Application of Foliar Sprays Containing Nitrogen, Magnesium, Zinc and Boron to Apple Trees. II. Effects on the Mineral Composition and Quality of the Fruit

Abstract

SummaryThe effects of foliar sprays containing N, Mg, Zn and B, applied alone or in combination, on the mineral composition and storage quality of apple fruits were measured. In general, Mg, Zn and B concentrations in cvs Cox and Discovery fruits were increased by sprays of MgSO4, ZnSO4 and ‘Solubor’ respectively. In both cultivars Solubor sprays enhanced red colour development but also increased skin cracking. ZnSO4 sprays tended to increase cracking in Discovery fruit. The incidence of flesh breakdown in stored Discovery and Cox apples was increased by Solubor sprays; conversely MgSO4 reduced breakdown.