Fusarium wilt, or more commonly known as Panama disease, has marked the history of bananas forever,
and its back. This plant disease became famous after completely disseminating banana production at
one point in history, with hardy any known method to combat the spread and damage it causes. With
worldwide presence, this disease threatens to reach corners of the planet that have yet to experience
new strains, creating a race to protect current and future bananas. A deadly disease with the only
apparent solution after every new strain attack production is finding new banana types that are
resistant to the fungus.
History of Panama Disease
Does history really repeat itself is the question many companies and experts are saying right now as
Panama disease is making a comeback, but first one must understand the historical significance of this
disease.
Since about the ending of the 19th century and beginning of the 20th century the dominating banana
type across the globe was the Gros Michel, specially in countries such as the United States. During the
1950’s this market dominance was quickly threatened to extension.
The fungus and its disease were first observed in Panama, which gave it the distinct name. Throughout
the years the fungus spread through Central America and South America. A quick spread combined with
devastating results made it a top priority for the banana industry. As cure or method to prevent the Gros
Michel banana plant to get infected the industry was forced find a new banana that tasted similar and
look the same, and most importantly was immune to the fungus. This outbreak was classified as Race 1.
At this point in history in when the Cavendish banana started its journey to becoming the most
produced and sold fruit in the world. This transition to a new variety took a couple years of hard
conditions for the banana market, as plantations all across the American confinement were wiping out
one by one.
The Effect of Panama Disease on the Banana Plant
Bananas have a special characteristic that very few fruits across the world share: every single fruit is
genetically identical to each other. Having an identical fruit brings many benefits to the market such as
making the production process highly specific and standardized, which brings immense control to the
supply chain. From planting to shipping, having the same fruit makes it extremely easy and viable to
produce, and the final consumer gets to enjoy the same taste and look every single time. Consumer
adoption has been a cornerstone for the rise of Cavendish banana, after highly expensive marketing
campaigns to introduce the new type of banana, consumers have gotten used to a perfect yellow
banana.
The identical nature of bananas made it an ideal target for the Fusarium fungus, which spreads from
plant to plant without having to combat new plant defenses. Not only does it have an easy path to
infecting the plant but it also spreads relatively easily. Dispersed by spores or infected material, this
disease travels on water or farming activities.
Fusarium fungus infects young roots or its bases, reaching the vascular bundles of the banana plant
which helps it spread all throughout the plant. The symptoms of an infected banana plant are what’s
called yellow or green leaf syndrome. In the first case the border of the banana leaves turns yellow,
eventually leading to bending of the petiole, and for the second case the green color of the leaves
persists which later leads to bending of the petiole. Other symptoms include the banana pseudo stem
splitting and causing the plant to collapse. An important distinction has to be made between symptoms
of bacterial wilt and Fusarium wilt, in which the first one starts from the younger leaves to the older
leaves, but Panama Disease is the opposite. Another important difference can be found on the growing
buds or suckers, which will have visible symptoms, such as distorted buds, in the case of the bacterial
wilt. This last characteristic leads infected plants with Panama disease to be planted without having any
indication of it being infected from the start.
Within a month or two most of the leaves turn yellow and collapse, leaving only the youngest of leaves,
which will turn into brown leaves that end up covering the pseudo steam as they bend. This fungus can
then survive in the soil for up to 30 years, making it the perfect recipe for disaster.
Recent Times
As explained above, Cavendish banana came to replace Gros Michel completely as it was found to be
the best alternative that was resistant to the Race 1 Panama disease. After the abrupt change the
banana industry flourished for many years as the fungus had no signs to make a comeback. A race 2 and
3 were discovered but those affected other banana varieties, not the most famous and commercialized
Cavendish variety. That was up until the 1990’s. In Southeast Asia the Race 4 kind was first spotted
which was seen to affect Cavendish banana plants. Spreading through most countries in Asia, and later
spreading to the Middle East and Africa, the concern began to grow that this disease would eventually
reach the Americas. With many of the top banana producing countries located in the American
continent measures started to rise. This new strain was carefully studied and country borders were
especially careful to mitigate any sign of contamination. For nearly two centuries these measures were
successful, mainly as the fungus has a mayor barrier before reaching the American continent: the vast
oceans. Events quickly changed when in August of 2019 the disease was found in Colombia, marking the
official spread of Race 4 or TR4 across the entire globe. Researchers, scientists, fruit companies, and
governments are starting a race to find a cure for this disease, a way to avoid spreading the fungus, or a
new type of banana that meets the needed characteristics. History might repeat itself, but this time
around it’s a race against the clock to stop it.