Early selection in Eucalyptus camaldulensis Dehnh. progenies in Savanna, Brazil

Genetic parameters were assessed and correlated to evaluate the feasibility of early selection for diameter at breast height (DBH) and total height (TH) in a half-sib progenies test of Eucalyptus camaldulensis. The test is established in the Santo Antonio do Leverger municipality, Mato Grosso State, Brazil, with 132 progenies, five blocks and three plants per plot at 3 x 2 m spacing. REML/BLUP procedure was applied at three and six years of age of trees for estimation. Analysis of deviance revealed no significance for progeny effects for variable TH in both age groups. Genetic parameters were of low magnitude and gains were almost zero. However, for variable DBH, significance in the analysis of deviance was recorded. The accuracies were of high magnitude and there was low heritability variation for the assessed ages. Gains with direct selection for DBH were 38.03% (DBH 3) and 34.86% (DBH 6), the genetic correlation between the two ages was high and positive (0.958) and the indirect selection gain was 33.65%, indicating a situation favourable to early selection. The results will subsidize the first breeding program of E. camaldulensis in the Mato Grosso State.   Key words: Forest tree improvement, half-sib progenies, indirect selection.