<p>An assessment of hybrids of medium staple cotton by fi ber quality in the Tashkent, Fergana and Kashkadarya regions of the Republic of Uzbekistan has been carried out. Four hybrid combinations of different genetic origins were tested. The analysis of the infl uence of the genotype and the environment on the manifestation of the qualitative parameters of the fi ber (length, specific breaking load, microneir) was carried out. High values were found in hybrids with <br /> the participation of the wild species G. trilobum Skovsted and the ruderal form G. Harknessii Brandg, as well as Bukhara-6 varieties. According to a three-year experiments, it was found that the variability of fi ber length is largely infl uenced by the genotype and unaccounted factors. The specifi c breaking load of a fi ber is signifi cantly infl uenced by the genotype, rather than the environment. The variability of the microneir of the fi ber largely depends on the environmental conditions.</p>