There are roughly a thousand kinds of banana on Earth. Almost every one that reaches a supermarket outside the tropics is the same one: Cavendish — a sterile triploid that makes no seeds and is propagated only by cutting pieces off itself. The global banana trade is not a crop. It is one plant, copied about a hundred billion times a year. And a soil fungus that can wait thirty years for it has now reached four continents.
≈50%
Cavendish share of all bananas grown
Cavendish is close to half of the 139.6 million tonnes of bananas produced worldwide — and nearly the entire 19.3-million-tonne export trade. Genetically, those exported fruits are indistinguishable from one another.
01One plant, everywhere
A crop with a population of one
Cavendish bananas are triploid (AAA) and parthenocarpic: the fruit forms without pollination, and the plant is effectively sterile. New plants come from suckers or tissue culture, so every plantation is a cutting of a cutting. Diversity exists — the world's largest banana gene bank in Leuven holds more than 1,700 accessions — but almost none of it is in the boxes on the ship.
Share of bananas grown worldwide, by type
Cavendish ≈47–50%
Plantains ≈21%
Other cultivars ≈32%
Share of bananas crossing a border, by type
Cavendish — nearly all of the export trade
Production shares: Munhoz et al., Frontiers in Plant Science, 2024 (Cavendish ≈50%, other cultivars 32%). Export dominance: Wang et al., Horticulture Research, 2023. Bar widths are proportional; the plantain slice is the residual.
~1,000
Known cultivated banana varieties
Conserved under UN mandate at the International Musa Transit Centre, KU Leuven — 1,700+ accessions, about 75% traditional landraces.
1
Cultivar behind the export trade
Every Cavendish shares one genome, one set of vulnerabilities, and one response to any pathogen that learns to attack it.
139.6 Mt
Bananas grown, 2023
Of which 19.3 Mt were exported. Ecuador alone shipped about 6.5 Mt — roughly a third of world trade.
02The colour scale
Seven shades, one supply chain
A banana is picked hard and green, chilled to 13.3 °C, and held dormant at sea for up to four weeks. It is not allowed to ripen until a room full of ethylene gas — 100 to 150 ppm at 15–20 °C — tells it to. The industry runs on a seven-stage colour scale, and a fruit that arrives at the wrong number is a fruit nobody buys.
1Dark green — picked, shipped
2Light green
3More green than yellow
4More yellow than green
5Yellow, green tips — on shelf
6Full yellow
7Flecked — end of sale
Colour stages and handling conditions: UC Davis Postharvest Technology Center, Banana (Cavendish) produce facts. Storage at 13.3 °C for ~28 days; ripening induced with 100–150 ppm ethylene, 90–95% RH.
03The fungus that waits
Tropical Race 4 keeps arriving
Fusarium wilt TR4 kills Cavendish, spreads on soil stuck to boots, tyres and tools, and survives in a field for up to thirty years after the last banana is pulled out. There is no effective chemical control. Between 2018 and 2024 the number of countries reporting it rose from 16 to 23 — and in 2019 it crossed into Latin America, which grows most of the world's exported fruit.
Country counts and Latin American arrival years: Munhoz et al., Frontiers in Plant Science, 2024. Ecuador: Agrocalidad confirmation, Dec 2024 (via Fruitnet). Map outline is hand-simplified and schematic, not survey-accurate.
30 years
Fungus survives in soil without a host
Infested land cannot simply be replanted. Quarantine, not cure, is the only working response.
1965
The last time this happened
Gros Michel — the export standard from the 1870s — was wiped out of world trade by an earlier race of the same fungus. Cavendish was the replacement because it resisted that strain. TR4 is the strain that beats Cavendish.
04The chemical treadmill
Fifty-two sprays a year
TR4 gets the headlines, but the routine cost of monoculture is black Sigatoka, a leaf-spot fungus fought from the air, year-round. Where pressure is highest, export plantations apply as many as 52 protectant sprays annually. The fungus keeps evolving resistance; the schedule keeps tightening.
Protectant fungicides high-pressure export blocks
52 /yr
Systemic fungicides same blocks
26 /yr
Vale do Ribeira, Brazil typical programme
15–20 /yr
Certified organic smallholders Piura, Peru
0
Synthetic fungicide applications per year against black Sigatoka. Sources: Arango Isaza et al., PLOS Genetics, 2016 (52 protectant / 26 systemic; ≈US$1,000 per hectare per year; more than 35% of production cost); CABI Agriculture & Bioscience, 2025 (Vale do Ribeira). Organic bar shown at zero synthetic applications.
$1,000
Fungicide cost per hectare per year
On large plantations. Disease control alone can exceed a third of total production cost.
>35%
Share of production cost spent on fungicides
A tax paid every year for the convenience of growing one identical plant across millions of hectares.
05The price that didn't move
Cheaper than in 1980
In June 1980 a pound of bananas cost American shoppers 35 cents. In June 2026 it cost 65 cents — an 87% rise across forty-six years, in a period when the general price level roughly quadrupled. Bananas are one of the few foods that got meaningfully cheaper in real terms. The efficiency that made that possible is the same uniformity that makes the crop fragile.
BLS average price, bananas ($/lb, June values)1980 price grown by CPI-U — calculated, not measured
Price series: US Bureau of Labor Statistics, CPI Average Price Data, series APU0000711211 (via FRED), June values 1980–2026. The dashed line is our own calculation from BLS CPI-U annual averages, with the 2026 index extrapolated — illustrative, not a published series.
06What is actually at stake
Four hundred million breakfasts
Outside the export trade, bananas and plantains are a staple — the fourth most important food crop by consumption after wheat, rice and maize. The people most exposed to a Cavendish collapse are not the shoppers who would pay a little more; they are the growers and eaters for whom bananas are a quarter of the day's calories.
400M+
People who depend on bananas & plantains
Grown in more than 135 countries, mostly for local consumption rather than for export.
15–27%
Of their daily calories
In parts of East Africa, banana consumption per person is the highest in the world.
$94B
Modelled loss from a 5-year delay
MODELLED FIGURE — a projection cited in the 2024 TR4 review for the cost of postponing resistant varieties by five years. Not an observed loss.
07Why it matters
The fix is diversity, and it is already being built
A resistant Cavendish exists. QCAV-4, developed at Queensland University of Technology with a resistance gene (RGA2) taken from a wild Southeast Asian banana, was approved by Australia's OGTR for commercial cultivation and by FSANZ for consumption in February 2024 — the first GM banana cleared anywhere. It came out of more than seven years of field trials in the Northern Territory.
Gene banks are the insurance policy. The 1,700+ accessions held at KU Leuven are the raw material for every future banana. They are cheap to maintain and irreplaceable if lost.
Buy the odd ones. Red bananas, apple bananas, plantains, Blue Java — where they are sold, buying them funds a second variety. A market with two bananas in it is more robust than a market with one.
Watch the boots, not the borders. TR4 moves in soil, on footwear and equipment. Farm biosecurity — footbaths, restricted access, cleaned machinery — is the only measure that has ever slowed it.
The lesson generalises. Uniformity is what makes a crop cheap and what makes it fail all at once. Bananas are simply the clearest case, because there is only one of them.