Abstract. The majority of interactions between seeds and machine units during harvesting and transport has a dynamic nature, so as there is essential to estimate the maximal impact energy delivered to seed, without failure of its structure. The testing apparatus was constructed in order to simulate dynamic loads to be found in harvesters and transporters. The experiment was conducted on four varieties of winter rape at various moisture content, maturity and size as well as spatial orientation of seeds versus beater. Each experimental combination was exposed to the similar striking energy. The amount of micro- and macro-damage of seeds was the measure of their resistance to dynamic loads.