Sugar beet is a valuable arable crop providing a large proportion of world sugar supplies. It is susceptible to a range of fungal and viral diseases, to most of which there is inadequate genetic resistance. Control instead relies largely on the use of pesticides. To increase the sustainability of sugar-beet cultivation, strong and durable genetic resistance is urgently needed. This review describes an IACR-Broom's Barn programme devoted to evaluating Beta germplasm for novel resistance to major viral and fungal diseases, and its progress in elucidating the numbers and locations of the genes responsible.