The objective of this investigation was to evaluate the effects of different crop management practices during three years of experimentation on sunflower cultivars characterised by different hull anatomy, in order to study the 'environment x genotype' interaction on hullability. The experiments were conducted from l99l to Ig93 at the Pisa University Experimental farm (latitude 43° and 41' North, Longitude 10 ° and 23, East), adopting three different combinations of water level and nitrogen availability and three different cultivars, Oscar, Viki, and Euroflor of Helianthus annuus L. The cv, Euroflor, characterised by thin hulls and high achene oil content, showed an unusual, positive relationship between seed oil content and hullability, thus offering breeders the possibility of overcoming the barrier of simultaneously improving these two characteristics. However, at the same time, considerable attention must be given to the pedo-climatic environmental conditions. In fact, this cultivar significantly improved its hullability with crop management practices that favoured light water and nitrogen deficits during the grain-filling period, while, in contrast, the other two earlier cultivars had better hullability characteristics with good water and nitrogen supplies.