Crescimento de um clone de eucalipto submetido a desrama e desbaste Growth of eucalypt clone submitted to pruning and thinning

Plantas de clone de Eucalyptus grandis, em região de Cerrado, no espaçamento inicial de 3 x 3 m, foram submetidas à desrama artificial e ao desbaste. Os tratamentos de desrama tiveram início em três idades diferentes: 16, 20 ou 28 meses. Foram utilizadas três a quatro intervenções de desrama, com remoção de copa em diferentes alturas, para atingir 6 m de fuste livre de nó, quando se iniciou a desrama aos 16 ou 20 meses, e duas a três intervenções, quando se iniciou aos 28 meses. Foram aplicados dois tratamentos de desbaste aos 55 meses, com remoção de 0 e 35% do número de mudas plantadas. O crescimento foi avaliado no período pós-desbaste, entre 55 e 93 meses de idade, por meio da análise do diâmetro (DAP), altura total (Ht), volume com casca (V), incremento periódico anual pós-desbaste (IPA) e incremento médio anual (IMA). Aos 93 meses, não foram observadas diferenças significativas (p>0,05) em DAP, Ht, V, IPA e IMA, entre os tratamentos de desrama, e na interação entre desrama e desbaste. No tratamento desramado até 1,5 m de altura, aos 16 meses, houve remoção de 80% da biomassa de folhas e galhos. Nesse tratamento, 65% dos indivíduos estavam com DAP inferior a 15 cm, em comparação com 35% nos demais tratamentos. A Ht no povoamento desbastado foi menor (pPlants of Eucalyptus grandis clone, established in a 3 x 3 m spacing, were submitted to pruning and thinning. Pruning treatments started at three ages: 16, 20 or 28 months. Three or four pruning interventions were applied at different tree heights to attain a 6 m log free of branches, when pruning started at the age of 16 or 20 months, and two or three pruning were applied for the treatments starting at the age of 28 months. At the age of 55 months, two thinning treatments were applied (control and removal of 35 % of the total planted seedlings). The plant growth after thinning was evaluated for the period between 55 to 93 months by analyzing diameter (DBH), total height (Ht), volume outside bark (V), periodic annual increment after thinning (PAI) and mean annual increment (MAI). At the age of 93 months, there were no significant differences (p>0.05) for the diameter at 1.3 m height (DBH), total height (Ht), volume outside bark (V), periodic annual increment after thinning (PAI) and mean annual increment (MAI) between artificial pruning treatments and for the pruning-thinning interaction. By pruning up to the height of 1.5 m in the first intervention, at the age of 16 months, there was a removal of 80 % of total leaves and branches. In this treatment, 65 % of the individuals presented diameter smaller than 15 cm in comparison to 35 % for the remaining treatments. The total height was significantly (p<0.05) higher in the non-thinned stand in comparison to the thinned one. The volume outside bark, PAI and MAI varied significantly (p