Zinc deficiency is prevalent in apple orchards throughout the Northeast. Zinc contained in various fungicides is partially effective in meeting zinc requirements of apple trees.
Foliar application of EDTA-zinc chelates in two or more post-bloom cover sprays are effective in supplying zinc under most conditions. Alternative materials for such applications are also being studied.
Post-harvest or pre-bloom plus post-harvest applications of alternative sources of zinc did not produce consistent improvement of growth, yield, fruit size or color, or subsequent season zinc levels in leaf samples. Application of chelated zinc through trickle irrigation systems has provided significant improvements in leaf-zinc levels and is considered to be an effective means of supplying this element.
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