Bioterrorism and Chocolate: an “Introduction to International Studies” lecture

Crinipellis perniciosa mushroom from
Image Number K8626-1
“Spores released from the fan-shaped basidiocarp of this inch-wide Crinipellis perniciosa mushroom can infect cacao trees and drastically reduce yields of the beans from which cocoa and chocolate products are made.” Photo Scott Bauer. Obtained from Wikipedia Commons

I’ve written before on this blog about the strange case of bioterrorism and chocolate in Brazil, and an incredible documentary on this topic. But I’ve also written a lecture on this event for my “Introduction to International Studies” class, which anyone teaching a similar class (Introduction to Latin American Studies or Brazilian history, or perhaps a class on commodities) is free to use.  In the lecture I’ve talked about my own experiences in the Amazon and Brazil, so you’ll have to make some edits. Or if you’d prefer to listen to this story, you can hear a version adapted from this lecture on my podcast Dispatch 7, global trends on all seven continents.

If anyone is interested in similar topics, you can also read my blog post about an alleged bioterrorism plan to target cocaine. 

Shawn Smallman

Bioterrorism and Chocolate


Witches Broom

Theobroma cacao





CEPLAC: Brazilian government agency charged with promoting cacao

Jorge Amado

Wade Davis, One River

Fusarium Wilt: disease of bananas; also known as Panama disease

Chocolate and the Amazon

  • There are many disputes about the origin of the cacao tree, Theobroma cacao
  • Some people argue that it comes from Mexico, where Aztec emperors used to drink a frothy drink made from chocolate mixed with chiles
  • Archaeologists have also found traces of chocolate on drinking pots in the American southwest
  • It must have been brought overland from Mexico
  • It had been used in Mexico for a very long time, between two and four thousand years (Purdy and Schmidt)
  • It was known to the great mother-culture of MesoAmerica, the Olmecs
  • The ancient Mayans treasured it as a food celebrated by the gods
  • It was in Mexico that chocolate was first truly domesticated
  • Still, many botanists argue that chocolate originally comes from the Amazon, where it is a common understory tree 
  • Most likely originated somewhere in the Ecuadoran Amazon (Schmitz and Shapiro)
  • The most genetically diverse region for cacao is the Amazon basin
  • Somehow was traded to Mexico
  • We know that trade channels existed between MesoAmerica and the Amazon, because maize/corn is found in the Amazon, but that was a plant from MesoAmerica
  • Historical accounts of trade up the Pacific coast from South America to Mexico
  • May have also traveled down the Orinoco to the north coast of South America, from which it traveled overland up through Central America
  • Remains a mystery how it reached the north
  • But it thrived there, free of many of the diseases and pests that plagued it in Amazonia
  • But it continued to exist, and to be important, in the Amazon
  • During the colonial period, canoes used to set out from cities on the mouth of the Amazon deep into the rainforest, in search of cacao planations, planted long ago by the native americans
  • They would return with large amounts of cacao beans
  • Whether or not cacao originates in the Amazon, it certainly has had a huge impact upon Brazil

Cacao and Brazil’s Northeast

  • Was brought to northeastern Brazil from the Amazon in 1746
  • For a long time, coffee and sugar were the key crops in the Northeast
  • Cacao became important after it began to be grown in commercially important quantities in the 1830s. 
  • Brazil’s northeast a region of extreme inequality
  • Early in Brazil’s history the northeast was the richest part of the country
  • Based upon sugar production with slavery
  • Late in the colonial period this entered into a slow decline
  • Gradually impoverished the region
  • Left a legacy of inequality
  • Social status defined by access to land
  • Landed elite: fabulously wealthy
  • The majority were a rural poor
  • The elites maintained their position and social standing with violence
  • The rich were known as colonel’s, because of their position in the National Guard during the empire
  • They often lived in Europe or major cities on the Brazilian coast, and counted on hired men to run their plantations for them
  • A region with severe human rights abuses, as the elites used violence to control the poor
  • Captured in the novels of Jorge Amado
  • I lived there for a summer: struck by the gold and jewels in the churches; the extreme poverty in the streets
  • The wealth of the cacao plantations gave the great landowners economic power nationally
  • Chocolate a part of this story, as are plant diseases in an unexpected way


The Arrival of Witches’ Broom in Bahia, and efforts to contain it

  • The chapter talks about the spread of chocolate as a global community
  • One of things that happened as it spread was that it left behind a host of diseases that have ominous names like witches’ broom
  • Witches’ broom is a fungus
  • Lands on a tree through spores
  • Creates pink mushrooms that grow on the tree
  • At first, this fungus greatly reduces a tree’s production of cacao
  • Over time, it kills the tree
  • It has a devastating impact upon cacao production
  • The disease has been known for a very long time
  • First described in Brazil in 1785 (Purdy and Schmidt)
  • It gradually spread throughout Latin America, between the late nineteenth and late twentieth century
  • In the wild, trees dispersed throughout the forest
  • On plantations, they are in close proximity
  • This creates a very different environment for plant diseases, which makes it much easier for them to spread
  • The disease was introduced into Brazil’s northeast, in Bahia, in May 1989
  • The government launched an eradication disease to stop it from spreading
  • Led by CEPLAC
  • Had been founded in 1957 to provide extension support to growers, and other services to the cacao industry
  • The cacao industry had been in decline
  • This agency was intended to revive it 
  • CEPLAC would take the lead fighting against witches’ broom
  • Faced its greatest challenge
  • A great campaign, because the Brazilian government knew how important cacao was to the economy
  • CEPLAC sprung into action
  • Worried that the organization would face severe criticism if it was not successful
  • Trees were pruned or cut down, and the remains burned
  • Entire strips bulldozers, and fungicides sprayed from mobile blowers on the trees
  • A helicopter was also used to spray the trees
  • They contained the initial outbreak
  • Then cacao growers about 60 miles away found another outbreak
  • Again, it could only have been brought there by people
  • It had been moved from the original area
  • Containment was no longer possible


Was the Disease Deliberately introduced?

  • Circumstantial evidence suggests that the introduction was deliberate. 
  • The first introduction was along a road, and the second along a river. Pereira, Almeida and Santos
  • It did not gradually appear from the edge of the plantations
  • From the start, it appeared at their heart of the plantations (best history: Pereira, Almeida and Santos, “Witches’ broom disease of cacao in Bahia”
  • In 1991 an article in the journal New Scientist  speculated that the disease had been deliberately introduced, to decrease the power of the rich elites
  • What better way to undermine their power than to destroy their wealth?
  • But for a long time, there was no hard evidence
  • There were only suspicions that the disease had been deliberately introduced
  • Then in 2007 Brazilian magazine Veja later published a confession by a man, Luis Enrique Franco Timoteo, and five other government employees of CEPLAC, as well as CEPLAC’s director, of having introduced the disease
  • All the accused were members of Brazil’s leftist political party the PT
  • What was shocking that the people accused were members of CEPLAC, the government organization charged with promoting and supporting cacao growth in the northeast (Jean-Phillipe Marelli, PhD)
  • In other words, the very agency that was supposed to support cacao was being accused of destroying it
  • Ironically, it was CEPLAC that was supposed to establish the quarantine regulations to keep disease out
  • One can only imagine the shock of this revelation
  • One has to wonder: how did CEPLAC employees, who had led the fight against the disease’s spread in the region in 1990s feel about this news
  • According to Louis Enrique, the purpose was to decrease the power of the great landowners
  • The man said that he had traveled to Amazonia more than once, and brought the infected material in rice bags
  • He said that CEPLAC employees then hung infected branches under trees in the region 
  • The article was published on June 20, 2007
  • Cacao growers were furious
  • Demanded a government investigation
  • After hearings, a jury stated that there was insufficient evidence to decide if CEPLAC employees were responsible for the outbreak
  • Should note that at the time that this was taking place, the highly popular president was a member of the PT
  • Currently a scientific debate over whether the evidence supports this allegations (for a history of the alleged confession and its likelihood see Jean-Phillippe Marelli, Solanum Lycopersicum as a model system to study pathogenicity mechanisms, PhD. dissertation, Pennsylvania State University
  • It is possible that Witches’ Broom was brought to Bahia by cacao workers from the Amazon. Pereira, Almeida et al, 743
  • We still don’t know for certain if the disease was deliberately introduced into Bahia for political reasons


Parallels to U.S. anthrax case

  • Reminds me of the anthrax scare after 9/11 in the United States
  • A series of envelopes filled with anthrax were sent to the media and political leaders
  • Intensive investigation, which ultimately identified the wrong suspect
  • Ultimately, a new suspect emerged
  • He committed suicide before he could be brought to trial
  • He was a government scientist working to create an anthrax vaccine
  • If he was responsible, what was his motivation
  • Was it to get more funding for vaccine research
  • Or was it something else that we can’t know
  • In both cases, it seems that the people hired to protect us against disease may have been the people who used it as a tool of destruction


The Impact of Witches’ Broom in Brazil

  • We can’t know the truth with certainty, beyond that it was brought by people
  • Over the course of several years in the 1990s production fell from 400,000 tons of cacao to 150,000 
  • Soon thereafter, cacao production had fallen by nearly eighty percent
  • There had been 600,000 hectares of cacao production in the northeastern state of Bahia
  • These were now devastated
  • Maps of the diseases spread show how it rapidly moved from where it was introduced to the entire cacao growing region
  • The disaster was so great that it had a social impact, (as Harold Schmitz and Howard-Yana Shapiro have described in a Scientific American article)
  • Farmers were not compensated for the loss of trees or revenue during containment efforts
  • The disease wiped out their livelihoods
  • People walked away from the land and moved to the cities
  • The shanty-towns in the Northeast grew even further
  • An entire economy undermined
  • Equipment lay unused
  • A vast reservoir of knowledge about cacao has disappeared as people have left the industry
  • The disease has now spread throughout Brazil
  • Need to note how important chocolate was to Brazil. In the 1990s Brazil was the second largest producer of chocolate in the world, after the Ivory Coast
  • The Americas are responsible for perhaps 20% of the world’s chocolate production (Queiroz, et al.)


Finding Resistant Strains

  • Plant geneticists are working hard to develop resistant plants
  • The challenge is that variants that may be resistant to witches broom may not yield high quality cacao
  • Currently there are expeditions into the Amazon, the homeland of cacao, to try to find trees that are resistant to cacao
  • They do exist
  • The first expedition took place to Suriname in 1902 (Purdy and Schmidt), so this effort has been taking place for a very long time
  • It will be possible to create variants that are both resistant and produce good cacao
  • But it takes time
  • Some plants at first seem to have resistance, then fail
  • There has been a lack of long term focus and funding
  • Farmers are hesitant to replace existing trees until they absolutely have too
  • Plant geneticists are working hard to create resistant strains, but their work will take a great deal of time
  • Creating new strains of the tree is the only economically viable way to resolve the problem
  • Far too expensive to treat the trees by pruning and removing growths
  • Chemicals are difficult to use to treat the problem, and far too expensive
  • In addition, they risk contaminating the cacao beans


Could Witches’ Broom spread to Africa or Indonesia

  • What happened in Brazil has broad implications
  • The disease has not yet left the Western hemisphere
  • European merchants brought cacao throughout their Empires, and in particular to West Africa, India and Indonesia
  • Because plantations there have come from a smaller number of trees that were originally brought from Latin America, they are less genetically diverse than cacao trees in the home region
  • This lack of diversity means that they have less resistance to disease and pests
  • They have also been troubled by diseases indigenous to the region, such as black pod rot
  • What if someone were to deliberately introduce witches’ broom into West Africa, or if the disease somehow spread naturally
  • The effects would be devastating
  • These trees are produced in plantations
  • Little reason to think that the outcome would be different than in Bahia



  • The example of witches’ broom is not unique
  • Rubber in the Amazon is naturally prey to a disease
  • For this reason trees grown dispersed throughout the forest
  • Rubber trees smuggled to Asia in 19th century, during the era of the rubber boom
  • Led to a collapse in the global price for rubber
  • Trees in the Amazon could be grown in plantations
  • People did not have to wander through the forest to find trees to tap
  • They could plant the trees in straight lines
  • Free from natural pests
  • Plantations vastly more effective
  • As Greg Grandin has described, Henry Ford tried to create rubber plantations in the Amazon in the 40s
  • They all failed
  • Has become a sign of American hubris, and the subject of a novel
  • The rubber blight remains an enduring threat
  • Wade Davis talks about this in his book One River
  • During World War Two, Davis’s mentor, Schultes, traveled throughout the Amazon, collecting forms of the rubber tree that were resistant to blight
  • But his work was abandoned, and the trees that he collected were either cut down or allowed to die
  • Fundamental problem: we rely on plantation production of crops in areas free from their natural pests
  • Plants have little genetic diversity
  • Very vulnerable to destruction
  • Rubber and chocolate are not unique



  • Jean Phillipe Marelli points to two other vulnerable plants
  • One is the banana, which is vulnerable to Fusarium Wilt
  • Bananas brought to the New World by the Brazilians in 1516
  • Center of cultivation now in Central America
  • Main drawback of banana production: the product is very perishable
  • U.S. investors created a railway industry in Central America, and a shipping industry that could quickly take bananas to American markets
  • Created a market
  • Had to teach U.S. consumers how to eat them
  • Chiquita banana lady
  • United Fruit Company, a U.S. corporation, came to have great political power in Central America
  • Not enough time to detail the sad history of banana production in Central America
  • One interesting point
  • The bananas that we eat today are not the same kind that people ate in the past
  • You don’t have to remember the names of the banana varieties
  • But it used to be that people ate the Gros Michel variety, before it was nearly annihilated by the Panama fungus
  • It in turn was replaced by another banana, the Cavendish
  • This is the banana that all of you eat with your cereal in the morning, or on your banana split
  • This banana is now also threatened by the same fungus
  • The race is on to find a cure in genetics labs all around the world
  • This threatens to wipe out entire crops, if not economies
  • The same problem
  • The crop is not diversified
  • There are hundreds of different varieties 
  • We eat only one
  • This makes the crop particularly susceptible to infection
  • The disease is now being transported world-wide
  • Bananas a popular food
  • People eat more bananas than apples and oranges combined
  • If anyone is interested in learning more, read Dan Koeppel’s book, Banana
  • I won’t go into detail know
  • But Marelli points out that coffee is another vulnerable crop



  • Bottom line, or modern system of food production relies on a handful of crops, which are not diverse, and are produced on a huge scale
  • This makes them vulnerable to disease, whether it be an invasive species spread by nature or by man
  • Inevitably, it will happen with other crops
  • Perhaps Witches’ Broom will spread to West Africa
  • Or the rubber blight will be brought to SE Asia
  • But the scale of the damage will be immense
  • For consumers, an inconvenience
  • But for the producing regions it will be an economic disaster



How can the world best prepare to face these threats?

Is the best way to respond with more genetic engineering, to create crops that are less vulnerable?

What could we as consumers do to help address this problem?

Can you think of other examples of this problem besides those that I have given in this lecture?

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