The alarming increase of utilization of chemical fertilizers for crops has stimulated the quest for organic residues with the potential for enhancing agricultural products. The manipueira is a liquid residue produced in the process of making flour or starch from cassava (Manihot esculenta Crantz.) with potential for use as agricultural fertilizers because of its rich macronutrient (K, N, Mg, P, Ca and S, in the quantitative order) content and with sufficient contents of all micronutrients except molybdenum. Thus, the objective of this work was to evaluate the initial development of cowpea bean (Vigna unguiculata (L.) Walp., cv. Corujinha) fertilized with mineral fertilization and manipueira. The research was performed between January and February 2017, in a greenhouse located in the city of Campina Grande (7º 13'50" S, 35º 52'52" W, 551 m asl), state of Paraíba, Brazil. The experimental design was completely randomized, involving 8 treatments and 3 replicates, totally 24 experimental units. The treatments included applying mineral fertilization using phosphorus; potassium; phosphorus and potassium in combination; organo-mineral fertilization with phosphorus and manipueira; and phosphorus combined with manipueira in different proportions (25, 50, 75 and 100 % of the manipueira recommended doses). Stem diameter, plant height, number of leaves, fresh shoot biomass and dry biomass of the aerial parts of the plant, fresh root biomass and dry root biomass were determined at 15 days after sowing. Data were subjected to the analysis of variance by F-test and the averages were compared by Tukey's test (p < 0.05). The results showed significant differences between the treatments evaluated. The most significant increases in bean growth and phytomass accumulation were occurred upon mineral fertilization with phosphorus on stem diameter, plant height, fresh shoot biomass and fresh and dry root biomass. Plants subjected to fertilization with phosphorus and different doses of manipueira exhibited a negative effect on the initial development stage of the cowpea (V4 stage) and it is not recommended as a substitute for the mineral fertilization for this culture in this period.