Araucaria angustifolia, commonly known as araucária or Paraná Pine, is a critically endangered plant species native to the south of Brazil. Cultivation of this species is an important approach to reduce eforestation while still generating income. The present study aimed to assess the effects of different substrate formulations on araucária seedlings growth, quality and chlorophyll levels in a substrate/container conjugate system, as an approach to promote plant propagation and cultivation. Seeds were sowed in four different substrate compositions: F73 (pine bark, coconut husk fiber, slow-release fertilizer [SRF] and hosphate fertilizers), F55 (pine bark, coconut husk fiber [in higher proportion {20% more} than F73], SRF and phosphate fertilizers), T55 (pine bark, Brazilian peat, SRF and phosphate fertilizers) and CC55 (pine bark, sphagnum peat moss, rice straw, SRF and phosphate fertilizers). Seedlings were kept in a nursery area in the substrate/container conjugate system, with manual irrigation. After 180 days from sowing, eedlings were evaluated regarding height, root-collar diameter, leaf and root areas, shoots and roots dry masses and levels of chlorophylls a, b and total chlorophylls. Sturdiness quotient and Dickson quality index (DQI) were also calculated based on the biometric variables. Substrates F73 and CC55 promoted better height and root-collar diameter growth in comparison to other substrates. Other variables related to seedlings growth and quality and chlorophyll levels did not differ according to the substrates. Root and total dry masses were positively correlated with DQI. Root-collar diameter presented high positive correlation with height, shoots dry mass and total dry mass of A.angustifolia seedlings.
