The ideal spacing of a tree species is the one that maximizes wood production. Spacing is an important matter to be considered in forest management researches. The present study aimed to evaluate the development of Pinus taeda L. in the region of Irati, southern Brazil, grown at different vital spaces (ranging from 1.0 m² to 16.0 m² per tree), provided by nine different spacing measures between plants of a field experiment carried out in randomized block design with five replications. This study was based on measures of height and diameter at breast height (DBH) on 25 trees within the plot, seven years after the planting of seedlings from a clonal seed orchard. Analyses of variance and regressions were used to interpret the results. Average volumes between 74.75 and 274.89 m³ per hectare have been verified. Considering production volume even with small diameters, one should opt for smaller spaces; when larger diameters are desired, the option should be for larger spaces. A better performance in the relationship between volume and diameter can be obtained using vital spaces between 5.0 m² and 8.0 m² for each tree.
spacing; volume production; annual increment