The objective of this study was to determine the best method of bacteria application and the dose of maximum technical efficiency for the growth and morphophysiological quality of Cordia alliodora seedlings in the northern Amazon. The variables under study were: shoot height (H), collar diameter (CD), number of leaves (NL), shoot dry mass (SDM, g plant-1 ), root dry mass (RDM, g plant-1 ) and total dry mass (TDM, g plant-1 ), Dickson quality index, contents of chlorophyll a, chlorophyll b and total chlorophyll, leaf area (LA, m2 m2 ) and nitrogen balance index (NBI). Foliar application of Azospirillum brasilense at the dose of maximum technical efficiency of 0.40 ml L -1 positively influences the increase of collar diameter in Cordia alliodora seedlings. Application via substrate at the dose of maximum technical efficiency of 0.41 ml L-1 leads to larger leaf area in Cordia alliodora seedlings. Application of Azospirillum brasilense at the appropriate doses through both leaves and substrate promotes increments in all physiological parameters studied in Cordia alliodora seedlings at 90 days after transplantation.