Main Article Content
Bioassays were made in field conditions, in Olhos D Água, Minas Gerais, Brazil, for evaluating pyroligneous extract action on seedlings of Eucalyptus grandis x Eucalyptus urophylla clones treated by irrigation. Seedlings 45 days old received the fertilization concentrated and the pyroligneous extract at different concentrations during 45 days, three applications per week. It was evaluated the height, the diameter, the dry mass of the aerial part of trees (DMA), the dry mass of the root (DMR) and the potential of root growth (PRG) of the seedlings. Pyroligneous extract (from 0.0 to 2.0%) did not promote additive effects on eucalyptus seedlings of E. grandis x E. urophylla clones. The increasing of the pyroligneous extract concentration reduced the diameter, DMA and DMR of eucalyptus seedlings. Application of 100% of the recommended rate of fertilizer produced higher height, dry mass of the aerial part of tree, dry mass of the root and potential of root growth of the seedlings of E. grandis x E. urophylla clones, than with 50%.