Supplementing the Nutrition of Bramley’s Seedling Apple with Phosphorus Sprays II. Effects on Fruit Composition and Storage Quality

Abstract

SummaryFour sprays of 1% KH2 P04 applied between mid-June and mid-July in each of three years consistently increased the P concentration in cv Bramley’s Seedling apples at harvest and reduced the incidence of senescent breakdown in the fruit after storage in air at 1.5°C for 32 weeks. Similar reductions in low temperature breakdown were recorded in two of the three years in air storage and in the third year in fruit stored in 8% CO2 at 3.5°C for 45 weeks. Phosphorus sprays also reduced the incidence of superficial scald and core flush in certain years. Although sprays applied between mid-July and mid-September also increased fruit P content the reduction in breakdown was negligible. In one trial KH2 PO4 sprays also increased the K concentration in the fruit and this was associated with the development of bitter pit in the stored fruit. Ca(H2 PO4)2 applied at an equivalent rate of P also increased fruit P concentrations and reduced the level of breakdown in store. The tendency of P sprays to increase the i...