The influence of phosphate fertilization, spacing and planting systems were evaluated on the yield of sweet potato roots Rainha Branca cv. The experiment was carried out from February to July/2004 in Quartz Psamment soil, in the Universidade Federal of Paraíba, Areia-PB, Brazil. It was used experimental design of randomized blocks in sub divided plots in four replications. In the main plots, twenty treatments were tested forming five levels of P2O5 (0, 100, 200, 300 and 400 kg ha-1), combined factorially with four spacing among plants (0.20, 0.30, 0.40 and 0.50 m) for 0.80 m among lines; and in subplots, two planting for ms (one and two stems/hole). The largest production of commercial/plant roots (662 g) was obtained in planting system with a stems/hill, in the spacing of 0.80 m x 0.50 m (25.000 plants ha-1) with 180 kg ha-1 of P2O5. The commercial roots productivity of sweet potato roots, considering P2O5 levels at planting system with one stems/hole, were 18.7 t ha-1 obtained with 210 kg ha-1 of P2O5. The productivity in the planting system using two stems/hole were 18.9 t ha-1, and it was reached with 231 kg ha-1 of P2O5. The largest productivity on spacing function (19.64 t ha-1) was obtained with 0.30 m among plants, in the planting system with two stems/holes (83.330 plants ha-1).
Ipomoea batatas; phosphate fertilization; population density; stems; revenue
