EN
The changes of morphological features of stems and leaves during 3-year experiments of two hybrid cultivars and one population cultivar of oilseed sunflower are described in this paper. Effects of variable environmental factors, sowing density, and different levels of nitrogen fertilization were analysed. The tested sunflower line hybrids were characterised by only slightly more consistent morphological features than the population variety. The most heritable features were the number of leaves on the shoots. The variability of other features were to the largest extent influenced by random factors.