Effects of Soil-Applied and Trunk and Petiole-Injected
Manganese on Manganese Content of Coconut Palm
Timothy K. Broschat and Joseph J. Doccola
Abstract: Manganese deficiency is a common and potentially fatal disorder of palms growing in highly leached and calcareous soils. Soil applications of MnSO4 may not always be effective in treating this disorder due to rapid oxidation of Mn to less available forms. Trunk injection with MnSO4 (2.0 g Mn) was found to be more effective in increasing foliar Mn concentrations than soil application (192 g Mn) or petiole injections with 0.1 g Mn in a single hole, or 0.5 g Mn divided among four holes. In contrast to trunk injection, neither petiole injections nor soil application of MnSO4 increased foliar Mn concentrations above that of the untreated control palms. Trunk injections, while effective, result in permanent wounds that could potentially serve as entry sites for the trunk pathogen Thielaviopsis paradoxa, especially on young palms with minimal trunks.
Keywords: Fertilization; Palm; Manganese Deficiency; Manganese Sulfate; Micronutrients