Panama disease is caused by a fusarium soil fungus (Race 1), which enters the plants through the roots and travels with water into the trunk and leaves, producing gels and gums that cut off the flow of water and nutrients, causing the plant to wilt, and exposing the rest of the plant to lethal amounts of sunlight. Prior to 1960, almost all commercial banana production centered on "Gros Michel", which was highly susceptible.[99] Cavendish was chosen as the replacement for Gros Michel because, among resistant cultivars, it produces the highest quality fruit. However, more care is required for shipping the Cavendish,[100] and its quality compared to Gros Michel is debated.[101]

According to current sources, a deadly form of Panama disease is infecting Cavendish. All plants are genetically identical, which prevents evolution of disease resistance. Researchers are examining hundreds of wild varieties for resistance.