Response of some Egyptian cotton cultivars growth, yield and fiber quality to different sources of nitrogen fertilizers and foliar zinc application

Abstract

Two field experiments were carried out in Agricultural Research and Experimental Station, Faculty of Agriculture, Cairo University, Giza, Egypt (2019 and 2020) to study the response of Egyptian cotton cultivars (Giza 92, Giza 94 and Giza 95) growth, yield and fiber properties to foliar zinc (Zn) rates (0, 100 and 200 ppm) and nitrogen (N) fertilizers sources; urea (U), ammonium nitrate (AN) and ammonium sulfate (AS). Cultivars, N sources and foliar Zn led to a significant effect on plant height, number of sympodial branches plant-1, total and open bolls plant-1, boll weight, seed index, seed cotton yield plant-1, seed cotton yield fed-1, fiber strength, and fineness. While, cultivars had a significant effect on the position of the 1st sympodial node, lint%, fiber length and uniformity index. Giza 95 was a superior in above parameter except seed index and fiber quality. While, Giza 92 was a superior in fiber quality. Significant of two and three interactions between studied factors existed on most of studied traits. Whereas, the highest values were obtained from plots treated with AS with foliar Zn at 200 ppm in most cases. Significant relationships were found between total boll and percentage of open boll plant-1; R2 = 0.76 (Giza 92), 0.89 (Giza 94) and 0.91 (Giza 95). Also, seed cotton yield fed.-1 with open bolls plant-1, boll weight and lint% (R2 = 0.862, 0.632 and 0.619, respectively). In such experimental soil conditions ammonium sulfate and foliar Zn at 200 ppm could be recommended to improve the cotton properties.