Efeito da intensidade de desrama na produção de Pinus elliottii Engelm., implantado em solo pobre, no estado do Rio Grande do Sul.

The effect of the pruning intensity on the production of Pinus elliottii Engelm. was studied in a randomized block design trial with 5 treatments and 3 repetitions. The treatments were: T1 – control, without pruning; T2 – pruning of the dead branches; T3 – pruning of 40% of the total height; T4 - pruning of 50% of the total height; and T5 – pruning of 60% of the total height. The diameter and wood volume were affected by the pruning intensity of the 11-year old stand. The control (263.5 m 3 /ha) and pruning of the dead branches (245.1 m 3 /ha) were different from all other treatments (pruning of 40% - 231.5 m 3 /ha; pruning of 50% - 225.5 m 3 /ha; and pruning of 60% -211.6 m 3 /ha). The smallest production loss was 12% on the 40% pruning, and the greatest loss was 20% on the 60% pruning treatment. It is concluded that pruning intensities below 40% of the total height should be employed because of the lower production losses, and increases in diameter and quality of the wood.