Developing cotton cultivars with a high yielding potential, nutrients extract and efficient, fiber attributes, earliness, high oil as well as protein cottonseed contents and pest resistance across variable environments is of great importance of cotton breeding programmer in Egypt. The field experiments were carried out at Agric. Res. and Exp. Stat., Fac. Agric., Cairo Univ., Giza, Egypt during 2017 season and repeated in 2018 season to evaluate the productivity and fiber technology response of three new released Egyptian cotton cultivars namely; Giza 93, Giza 94 and Giza 95 to three nitrogen fertilizer sources i.e. urea (U -46.5%N), ammonium nitrate (AN-33.5%N) and ammonium sulfate (AS -20.5%N). The randomized complete block design with split-plot arrangement with three replications was used. The main plots were devoted to cotton cultivars and the nitrogen fertilizer sources was randomly distributed in sub-plots. Giza 93 cultivar had the superiority over other cultivars concerning growth attributes, yield and yield components, chemical and biochemical constituents of foliage and seeds of cotton as well as fiber technology parameters. Generally, nitrogen fertilizer sources had a significant effect on growth attributes, yield as well as its components, fiber technological parameters, chemical and biochemical constituents of foliage and seeds of cotton whereas, ammonium sulfate was superior in plant height, 1 st sympodial node, no. sympodial branches plant -1 , no. total bolls plant -1 , boll weight, seed index, lint %, seed cotton yield fed -1 , fiber technological parameters, chemical as well as biochemical constituents of foliage and seeds of cotton. Significant cotton cultivars × nitrogen fertilizer sources interactions existed on most of studied traits.
