Estimation of oleoresin yield from Copaifera spp. in primary forest in meridional Amazon

Abstract

The objectives of this research were to verify the relationships between the dendrometric and edaphic variables with the yield of oleoresin from Copaifera spp., and to adjust equations to predict yield from a primary forest. Thirty Copaifera spp. trees were selected to extract oleoresins over 24 hours, using a 1.91 cm (¾ inch) auger. In addition, data were collected on tree size and the edaphic characteristics of the topsoil around of each tree. Principal components analysis was used to verify the relationships between variables and a regression analysis was used to verify variables that may be best to predict oleoresin yield. After the principal components analysis, the only variable related to the oleoresin yield was the stem height, which had the best adjusted coefficient of determination (0.84) and relative standard error (13.11%). We found the yield of oleoresin from Copaifera spp. in primary a forest had a significant and positive correlation with the stem height, whereas no significant correlations were found between yield, or any other dendrometric or topsoil variables studied.