The intensity of the first selective thinning was evaluated in two plantations, 3.0 x 3.0 m. In the four year old plantation, the thinning was 20%, 30% and 40% in density and in the five year old, it was 30%, 40% and 50%, and the respective controls (0%). Each treatment was applied in eight random blocks of 35 trees, beyond the border. One year after thinning at the age of four, the DBH, total height (H), and average by tree of basal area (<img border=0 src="/img/revistas/aa/v38n2/a05G.gif" align=absmiddle>) and of volume (<img border=0 src="/img/revistas/aa/v38n2/a05V.gif" align=absmiddle>) presented no differences among the treatments; the current annual increment (CAIV) was not affected by the intensities. In the plantation thinned at the age of five, the CAIV and H were similar in all treatments; the DBH, <img border=0 src="/img/revistas/aa/v38n2/a05G.gif" align=absmiddle>and <img border=0 src="/img/revistas/aa/v38n2/a05V.gif" align=absmiddle>were not affected by the tested intensities, but they were greater than the control. The first selective thinning may be applied at the age of five, in Tectona grandis plantations with similar conditions, at any tested intensity.
First selective thinning; Reforestation; Teak; Thinning intensities
