Effect of Placement of Phosphorus Fertilizer and Lime upon Growth of ‘Delicious’ and ‘Golden Delicious’ Apple Trees1

Abstract

Surface applications of dolomitic limestone raised the pH from 4.3 to 6.2 with diminishing effect to 15 cm. Although the pH was affected to 15 cm the available Ca was raised only to a depth of 7.5 cm. When the lime was applied in discrete zones as subsurface applications, the pH was raised to 6.1 and maintained at 5.8 to a depth of 30 cm. When lime and superphosphate were applied on the surface the distribution of Ca and P with depth was improved. Concentrations of Ca and P in leaf tissue of ‘Delicious’ and ‘Golden Delicious’ (Malusdomestica Borkh.) apple trees were increased more by subsurface than surface applications of lime and superphosphate. However, the greater effectiveness of subsurface over surface applications in maintaining leaf concentrations was not sustained and did not result in increased growth. Growth responses were obtained from applications of superphosphate and lime, regardless of method of application. Leaf Ca and P concentrations of 0.95–1.10 and 0.20–0.25, respectively, were associated with maximum growth.

Improved Performance of Bearing ‘Delicious’ Apple Trees with Nitrogen and Phosphate Fertilization in a Low-phosphorus Soil

“…For many decades, N fertilizer has been the primary nutrient element recommended for apple production in Washington (1). Although a response of apple trees to P is reported to be rare in commercial orchards (3,4), recent investigations have shown a marked response to soil-applied P by young apple trees grown in low-P soils in the Pacific Northwest (7,8) and in other areas (10)(11)(12). Koch et al (5) reported a response of apple seedlings to incorporations of P into fumigated soil with or without inoculations of mycorrhizae.…”