Variation of Foliar Content of Nutriments of Gmelina arborea in the Counties of Osa, Golfito and Corredores, Costa Rica

Abstract

We assessed the variation of foliar nutriments concentration in 12 plantations of G. arborea (melina) with ages between 1-12 years old, of the Cantons of Osa, Golfito and Corredores in Costa Rica. A foliar sampling of outer upper-top, inner top, outer half and inner half-top was carried out in the rainy and dry seasons. Forty five dominant trees (2 trees by season by age) were selected. A full chemical analysis and aluminum was performed in each sample. Variations in foliar concentrations due to the time of sampling were obtained with a higher N (2.99%), K (1.14%), Fe (91 mgkg- 1) and Al (53 mgkg- 1) in the rainy season, and Ca (1.42%) and Mn (95 mgkg- 1) in the dry season. Concentrations did not vary according to the position of the leaves in the top, with the exception of the Ca, which presented higher concentrations in the inner half-top (1.40%) with respect to the outer upper-top (1.02%). The age caused variations in Ca, K, B and Fe. A foliar sampling protocol was established and determined foliar concentration ranges of macro and micronutrients for the species in the Costa Rican Southern area.

Keywords

• Foliar analysis
• foliar concentration ranges
• leaf sampling
• macronutrients
• micronutrients