EN
European bladder nut has its northern limit in Poland and is legally protected. Climatic conditions, edible seeds attractive for small animals and seed dormancy to a large extent affect its restocking under natural conditions. The aim of this study was to determine conditions for seed dormancy release. Nuts dried after collection to ca 11% of moisture content (fresh weight basis) may be stored without loss of seed viability for over 1 year in a cold store at the temperature of -3oC. For the purpose of seed dormancy release nuts need to be stratified. Seed dormancy release was found highest after the application of warm-followed-by-cold stratification, first for 4-6 weeks at the temperature of 15oC or at cyclically alternating temperature of 10~20oC (24+24 h/cycle), followed by 16-18 weeks at 3oC. Seeds germinate at 3oC with the same rate as at cyclically alternating temperature of 3~15oC (16+8 h/day). Drying of nuts at room temperature to approx. 11% during the warm stratification phase (after 2 or 4 weeks) and further stratification resulted in a significant increase in seed germinability. In some seed lots scarification of nuts (dried during the warm stratification phase) contributes to a further significant increase of seed germinability.