It has been estimated that 80 per cent of global production is under threat from Tropical Race 4. The term TR4 was coined to distinguish the strains that readily cause disease in Cavendish cultivars from the ones that need the presence of predisposing factors, such as low temperatures, to cause disease.
While the fungus is not harmful to humans, it has the potential to eventually wipe out Cavendish bananas, according to experts. Millions of people around the world rely on bananas and plantains as a staple food and as a cash crop.
The pathogen attacks the roots of the banana causing the Banana Fusarium Wilt disease by clogging its vascular system. Symptoms are more obvious at particular times of the year and crop stage. As bunch growth requires additional nutrients and water, this may promote appearance of symptoms. For example, plants may look healthy until bunches emerge, then suddenly start to show leaf yellowing and wilt.
The fungus spreads through infected plant materials and contaminated soil particles attached to items such as farm tools, shoes, clothes, animals and vehicles. Irrigation and drainage water also play a critical role in its spread.
There are 4 races of Panama disease:
*Race 1 attacks Lady Finger, Sugar and Ducasse, but not Cavendish bananas.
*Race 2 attacks cooking bananas like Bluggoe and Blue Java bananas.
*Race 3 attacks only Heliconia species, not bananas.
*Race 4 attacks nearly all varieties of bananas, including the main commercial variety, Cavendish.
Topical Race 4 disease
