By the mid-1900s, the export trade was forced to convert to resistant cultivars in the Cavendish subgroup (8). These cultivars continue to perform well in the western tropics and remain the clones on which the trades are based (Fig. 3). However, in several areas in the Eastern Hemisphere these cultivars are now damaged by Panama disease (Fig. 4). These losses are significant, and signal a serious threat to production in the Western Hemisphere because there is currently no acceptable replacement for the Cavendish cultivars. Furthermore, because the variant of the pathogen that is responsible for these outbreaks also affects plantain, this important staple food is threatened as well.