Cassava brown streak disease (CBSD) is a devastating disease that causes poor yields of cassava. It causes rotting of the storage roots and the spoilt roots can not be eaten. CBSD is caused by two viruses; (i) Cassava brown streak virus ((BSV), (ii) Ugandan cassava brown streak virus (U(BSV). A virus can not be seen with the naked eye and only survives inside a living organism. CBSD is present in Uganda, Kenya, Tanzania, Malawi, Mozambique and Rwanda.