The objective of this work was to evaluate the effect os three daily gross irrigation depths (8,11 and 14 mm) applied in two irrigation frequencies (two and four times a day) on the initial development and quality of Piptadenia gonoacantha (Mart.) J. F. Macbr. seedlings. Increases in irrigation efficiency do not necessarily produce a greater development of morphological parameters and root system quality of seedlings in the nursery. The 11 mm irrigation depth is more efficient than the 14 mm and uses 21% less water. The 11 mm irrigation depth applied in two irrigation frequencies produce Piptadenia gonoacantha seedlings with optimum root systems and proper morphological development in the nursery, which continues after planting.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)