Nutrition of apple and pear trees with foliar sprays, trunk injections or soil applications of iron compounds

Abstract

Bearing apple (Malus domestica Borkh.) and pear (Pyrus communis L.) trees were treated with various iron (Fe) and sulfur (S) compounds in an attempt to correct or reduce severe Fe chlorosis. Fall plus spring trunk injections of ferrous sulfate solution (1.0% w: w) were the most effective and long lasting (3 or 4 years) method for reducing Fe chlorosis. Certain foliar sprays, especially Fe‐lignosulfonates, resulted in improved greening of the leaves and fruit, but the effect was of short duration (only lasting for the season of application). Soil applications of Fe and S to either the poorly drained or calcareous soils had limited and variable effectiveness on reducing Fe chlorosis. Limiting irrigation water in the poorly drained pear orchards or irrigating less but at more frequent intervals in the high pH soils of the apple orchards reduced iron chlorosis.

Key words:

• Iron chlorosis
• soil‐water management
• mineral composition of fruit and leaves