The cultivation of trap crops resistant against the beet cyst nematode (BCN) Heterodera schachtii (Schmidt) is performed on 40% of Germany’s sugar beet fields. Under northern German conditions in terms of soil, climate and management (15 study sites in 2012/2013–2014/2015) the effect of white mustard trap crop, a plant species mixture and a straw mulch reference was investigated on (i) the beet cyst nematode population dynamics in the soil, and
(ii) N-supply, yield and quality of subsequent sugar beets. When the trap crop produced an above-ground biomass > 2 t dry matter ha-1, cultivation of BCN resistant mustard tended to decrease BCN population better compared to straw mulch and species mixture. However, even a good trap crop did not increase N supply and yield of BCN tolerant sugar beets.