LONGITUDINAL RESIDUAL STRAIN (DRL) AND ITS RELATIONSHIP WITH THE CHARACTERISTICS OF THE TREE GROWTH IN Eucalyptus CLONES

Abstract

The objectives of the present study were: a) to verify the variation of DRL between two longitudinal position (1,3 m and 3 m height) in the stem of trees; b) to determine the relationship between DRL with diameter at 1,3 m of soil height (DBH) and total height (h) and; d) to estimate genetic and phenotypic parameters of the tudied characteristics. Eleven natural hybrid Eucalyptus clones were used. These clones were sampled at the Fazenda Riacho, which belongs to the Companhia Mineira de Metais of the Votorantim Group, located at Paracatu, region Northwest of Minas Gerais State, Brazil. According to the results the extensometer was efficient and fast for the measurement of DRL, becoming a useful tool to identify trees with different intensities of growth stresses. The differences of DRL amongst clones were statistically significant, however the differences of DRL between the two longitudinal positions in the stem were not statistically significant. There was no significant statistical correlation between DRL and growth characteristics of the trees. Both DRL and growth characteristics resulted in high genetic heritability, indicating that these characteristics are under high genetic control, and therefore with potential for genetic improvement.