The study presents results of investigations concerning the effect of environmental conditions on the morphological and physical traits of the stalk and the degree of lodging in barley (Hordeum vulgare). The object of the experiments were doubled haploid lines (DH) obtained from F1 hybrids between the hulled DH line RK63/1 and the hull-less breeding line 1N86. The DH lines, the initial forms, F1 and F2 hybrids were examined in the course of a three-year field experiment. The length, diameter and thickness of the stem wall, the elasticity of the stem (Young�s modulus) and the degree of lodging were analyzed in the study. A significant effect of the year, genotype and the genotype x year (G x E) interaction on the variability of the investigated traits was found. The evaluation and testing of the comparisons between the hulled and hull-less barley lines showed that hulled genotypes were characterized by a significantly thicker and longer stem, a bigger elasticity and a lower degree of lodging. The size and direction of changes between the hulled and hull-less lines in terms of the traits analyzed depended on environmental conditions.