An experiment was conducted at the Universidade Federal Rural do Semi-arid in Mossoro, RN with the aim of evaluating the behavior of cotton ( Gossypium hirsutum L. race latifolium Hatch) 8H cultivar, in terms of growth when irrigated with treated domestic sewage. The experimental design was in randomized blocks with split plots and in plots were tested dilutions of wastewater [25% - T1, 50% - T2, 75% - T3 and 100% of wastewater - T4 and supply water with mineral fertilizer - T5] in two soils of contrasting textures. Irrigation with wastewater significantly influenced the growth of cotton plants, the rate of emergence, the germination percentage, plant height, stem diameter and leaf area, growing linearly until an optimal dose, as the proportion of use of domestic effluent. The positive effect of the accumulation of nutrient in soil applied by fertigation on the variables studied is also highlighted. The irrigation with treated wastewater can offset conventional fertilization of cotton.
