Variação dimensional da madeira de clones de Eucalyptus cultivados em diferentes espaçamentos

Abstract

The objectives of this work were: to evaluate the effect of spacing upon total shrinkage of wood as well as estimate the genetic and phenotypic parameters of 12 natural hybrid clones of the genus Eucalyptus, in addition to evaluatie the clone x spacing interaction. The this end, three experiments have been set up in two sites. The clones were divided into two groups. Clones 1 through 6 have been planted on the Bom Sucesso farm, town of Vazante-MG, Brazil and clones 7 through 12 on the Riacho farm, situated in the town of Paracatu-MG, Brazil. In each site, three spacings (6,0 x 2,0; 6,0 x 3,0; 6,0 x 4,0 m) were utilized, each being regarded as a distinct experiment. The experiment design was in randomized blocks, with three replications and 6 treatments (clones). Plot size was of 288 m2. At 74 months old, a 1,3 m log was removed, that is, at the BHD for making the proof-bodies. The total shrinkage was evaluated at the radial, tangential and longitudinal planes, as well the total volumetric shrinkage. The results found, from the joint analysis, showed that the spacing effect was not significant for the radial, longitudinal and volumetric shrinkage. Both groups of clones presented distinguished behavior as to the clone x spacing interaction. Clones 1 through 6 presented clone x spacing interaction to longitudinal shrinkage and clones 7 through 12 presented interaction to the tangential, longitudinal and volumetric shrinkages. All groups of clones presented genetic variability for the evaluated shrinkages.