This study evaluated the effect of different sources of organic fertilizer and their most appropriate proportions to produce Toona ciliata seedlings. Broiler litter and cattle manure were used as organic fertilizer at four proportions in the substrate (0, 15, 30, and 45%). A control treatment was adopted with 6 kg controlled-release fertilizers (m-3 substrate). The following parameters were assessed: germination, seedling height, stem diameter, and shoot and root dry matter, as well as the Dickson Quality Index. Cattle manure did not provide satisfactory results, whereas the use of broiler litter in the substrate resulted in seedling development similar to that of the control treatment. In conclusion, concentrations up to 30% of broiler litter can be recommended to substrate composition, and greater proportions of this compound (>30%) preclude seed germination.
