Longevity of ferric ammonium citrate treatments in oak

Abstract

Iron deficiency is usually caused by high soil pH. Planting tolerant species or treating the pH problem directly are the preferred methods for managing this problem. However, altering the pH of a calcarious soil can be a lengthy and costly exercise. Trunk injection of ferric ammonium citrate and urea provides a quick, dramatic, and long-lasting reduction in symptoms of iron deficiency of both red and white oak. In addition, the low price of the materials (less than US$ 0.20 per in. of trunk diameter) also makes this an economical treatment.