The sewage sludge is a waste from sewage treatment plants, which can be used in formulations of substrates for seedling production. This study aimed to evaluate the effects of different proportions of sewage sludge, soil and commercial substrate on the growth characteristics of Tectona grandis seedlings in tubes of 120 cm³ volume capacity. The sewage sludge used came from the STP's Cachoeiro de Itapemirim / ES. The seedlings were grown in the forest nursery / CCA / UFES. The statistical design used in the experiment was completely randomized design (CRD) with six treatments and five replications. The treatments constituted of sewage sludge : commercial substrate: soil (v: v: v), which corresponded to 20:70:10 (T1), 40:50:10 (T2), 60:30:10 (T3), 80 : 10:10 (T4), 90:0:10 (T5) and the control treatment with 0:90:10 (T6). All variables assessed were significant at the 5% level of probability. The control (T6) showed results statistically equal to or lower than the treatments T3 with 60% of sewage sludge concentration (T3). It follows then that the use of sewage sludge in seedling production is feasible and promising, however, used in a proper proportion.
Biosolid; morphological characteristics; seedling quality
