Yield of sweet potato (Ipomoea batatas (L.) Lam.) fertilized with cattle manure and biofertilizer

Aiming to evaluate the sweet potato (Ipomoea batatas (L.) Lam.) yield fertilization with bovine manure and biofertilizer, an experiment was carried out from January to July, 2004, on USTIPSAMMENT soil, at Universidade Federal da Paraiba, Areia-PB. The Experimental outline used was randomized blocks, with four replications and, treatments distributed in factorial arrangement 6 x 2, being six levels of bovine manure (0, 10, 20, 30, 40, 50 t ha(-1)) and absence and presence of biofertilizer. Plots were constituted by 80 plants, spaced 80 x 30 cm. Commercial roots number per plant reached maximum values estimated of 2.0 and 1.7 roots, respectively, on levels of 26 e 25 t ha(-1) of bovine manure in presence and absence of biofertilizer. The medium weight of commercial roots of sweet potato increased, with elevation of bovine manure levels, with maximum weights of 360 e 224 g, in presence and absence of biofertilizer. The levels of 25.6 and 24.4 t ha(-1) of bovine manure, in presence and absence of biofertilizer, presented the maximum of total yield of 21.4 and 21.2 t ha(-1), respectively. Maximum yield of commercial roots, 15.2 and 12.9 t ha(-1) were reached with 25.5 and 21.3 t ha(-1) of bovine manure, under presence and absence of biofertilizer, respectively.