Composição química nutricional do Mogno Africano em Várzea Alegre (CE): micronutrientes.

Abstract

Knowledge of nutritional requirements of African mahogany (Khaya spp.) considering growth and biomass distribution is important to its efficient cultivation, especially in Brazilian semiarid conditions. Considering that African mahogany plantations in Brazil are recent, there is a need for research on nutrition of this species. The objective of this study was to evaluate the nutritional status of mahogany plants growing in field conditions in the semiarid region of Ceará, with different ages, with emphasis on essential micronutrients. Data were collected from 4 contiguous areas: the first planted with 5.4yearold Khaya ivorensis plants, the second with 5.4yearold Khaya senegalensis, the third with 1.4yearold K. ivorensis, and the fourth with 2.4yearold K. senegalensis. Analysis of the data considered two species (Khaya ivorensis and Khaya senegalensis) in two life phases (Young 1.4to2.4yearold plants and 5.4yearold plants), resulting in four combinations of species and plant age. Freshly harvested leaves of 40 mahogany plants were collected in four cardinal points at each plantation. The leaves were sent to analysis in the Laboratory of Agronomic and Environmental Analysis FULLIN, in Linhares ES. Boron content was higher in Khaya senegalensis and showed a trend to be higher in young plants; Iron content was higher in Khaya ivorensis, especieally in older plants. The two African mahogany plants are not very demanding for Zinc; are well supplied with Iron, presenting adequate levels for their full development. The content values of Boron in Khaya senegalensis leaves can be considered high compared to other forest species and, independent of studied age and species, micronutrient content values in leaf followed the decreasing order: B > Fe > Mn > Cu > Zn.