Whether the maturity of Pima cotton can be enhanced by manipulating rates of nitrogen and phosphorus fertilization was tested between 1990 and 1992. Plant growth and lint yield were significantly reduced and maturity significantly enhanced by nitrogen deficiency only when residual nitrogen was depleted by a non-fertilized previous corn crop. Depletion of residual phosphorus by continuous non-fertilized corn resulted in significant reduction of plant growth and lint yield but did not affect maturity. While high rates of nitrogen fertilization seemed to have a delaying effect, high rates of phosphorus did not affect maturity.