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close this bookQuiet Revolutionaries - A Look at the Campaign by Agricultural Scientists to Fight Hunger (World Bank)
View the document(introduction...)
View the documentThe people behind this essay
View the documentForeword
View the documentA costly mistake
View the documentA tiny but effective wasp
View the documentMoving to Benin
View the documentMite against Mite
View the documentGood works and deals
View the documentOrganizing the CGIAR
View the documentThe second-generation centers
View the documentThe question of quarantine
View the documentManaging a gene bank
View the documentRights to intellectual property
View the documentA new kind of bread
View the documentA taste of honey
View the documentStarch and alcohol

Rights to intellectual property

But who owns the rights to these innovations that biotechnology in particular has made possible innovations from breeding high-yielding varieties to genetic manipulation? More and more biotech research is in private hands; companies have to invest heavily and they may have to wait a number of years before a product is released. Private industry, and increasingly public research institutions, want to protect their intellectual property from "unauthorized use.',

The CGlAR centers are having to debate whether to alter their "open-door" policy and break with their tradition of free scientific exchange when it comes to distributing germplasm and sharing their breakthroughs. Open access to genetic material is a principle worth fighting for, many argue' but they need some protection against misappropriation by commercial companies.
It's a debate that rumbles wearily through many a meeting; a subject that many natural scientists seem, perhaps understandably, reluctant to grapple with. But the trend toward protecting intellectual property has gone too far now to be ignored by anyone.

Cooking and Eating

Stopped at a food stall by the roadside in a village just outside Cartagena, the historic port on Colombia's Caribbean coast a place that reverberates with piratical legends and ordered a cassava snack The sleepy-eyed, teenage girl hadn't any ready and said why didn't I try a maize snack instead. I was polite but adamant and handed over 100 pesos (15 cents). She sighed and got busy reheating the cooking oil. Eventually she handed me a ball of cassava filled with meat—a bit greasy and starchy but certainly filling.

The simplest way of eating cassava is to peel it and boil it for about 30 minutes until it's soft. Then it can be cut into slices and deep fried. "We eat fried cassava like French fries," a European resident of Colombia said. ´'Absolutely spectacular— delicious. You can eat them untie beef, you can eat them with fish, you can eat them with whatever you want."

There are many more imaginative ways of preparing it And cooking it or processing it solves the problems of cassava's two "dark secrets"—it contains cyanide and it deteriorates rapidly as soon as it's pulled out of the ground.

We turned off the road and stopped at a processing plant where a group of fanners were gossiping in the shade. Rupert Best, who now heads CIAT's cassava program, pulled up some theirs and we joined them. Four years ago their village was hit by a hurricane; they talked about it as if it were already ancient history. Life brought this land of terror; man just had to get over it

"It swept away the houses?" I asked.
"Of course."
"Did anyone lose their life?'
"One person did drown, farther down there," a farmer said, pointing in the direction of the river.
"Did the government give you any help to rebuild?"

Another farmer pulled the wide brim of his hat further forward, making the shadows on his creased face even darker. He said: "We got no help. There was money for this area but a big people took it away."

A small boy sitting on an American-made weighing machine lost interest in the adult talk kicked one of the wheels with his right foot. It moved him forward a few inches. Someone brought a crate of Coca Colas, prized off the tops, and handed them around. In the vast sly, the equatorial sun seemed to be in the exact center. Some clouds, which briefly promised rain, came and then went.

The first farmer said he had two hectares of cassava. When he needed some, he just went out and pulled them out of the ground.

"Did your father grow cassava?" I asked him.
"Of course. My father taught me how to grow it and his father taught him."
"How do you eat it?"
"Boil it and eat it with meat. At lunch, maybe, with plantains and yams. In a soup or stew."
"And again in the evening?"
"No. Rice, meat, and maybe an egg in the evening. We eat cassava for breakfast and lunch. But if we have some money we buy rice for the evening."
"Is there enough food?"

He looked around, his eyes staring out toward the fields.

"Last year was a bad year because of the weather. The crops aren't mature yet, so there's a scarcity of food. Some are-having to buy food at the moment The cassavas are still small."
"You know that cassava has a toxic substance in it? You know how to get rid of it by cooking or processing?"
"Of course. It gives it a bitter taste."

And What about the Cyanide?

The most important "dark secret" about cassava-the one that still causes fierce arguments within the agricultural community and their political masters that it contains cyanide. Or more correctly, cyanide is produced by a complex reaction when the cells are ruptured. And cyanide is, of course, highly poisonous.

"If you mash up the plant you get a wonderful smell of almonds," said R D. Cooke of Britain's National Resources Institute, he stood in the blazing heat of a cassava field pointing out cyanide's tell-tale characteristic Of course, I remembered, it was the "scent of bitter almonds" that told Dr. Juvenal Urbino, the hero of Gabriel Garcia Marquez's novel Love in a Time of Cholera, that a dead man he had been called to examine in a Cartagena house had committed suicide with the help of cyanide. There was no need for an autopsy.

Rumours about how dangerous cassava is to eat have always been around. One side in the debate states that acute toxicity is so rare that the presence of cyanide is irrelevant; the other side sometimes creates alarm ("it's just too dangerous"), arguing that farmers should be encouraged to grow other crops. Until recently, Cooke explained, it was difficult to measure the cyanide content accurately. But now, with new tests, the overwhelming opinion among scientists is that "cyarude need not be a problem if the cassava is processed in the traditional manner." And that traditional manner can mean simply boiling it or pounding it

Stories about poisonings and death became so bad in Nigeria picked up and spread by some newspapers that a workshop was held in Ibadan in 1989 to thrash the whole issue out. One doctor told the workshop, which included journalists, how three patients from the same family were brought to him. They were vomiting and in a coma, and they blamed the gari, the cassava flour. They all died And the doctor, after talking blood and urine tests, found traces of cyanide.

"Then we reviewed the case," said Mpoko Bokanga, a Zairean biochemist at IITA who told me the tale. The amount in the blood and urine was too large to have come from a meal of gari, he said. And since the gari had been bought on the street, the intoxication should not have been localized to just those three people from the same family. The conclusion was that there must have been some other contaminant that came into contact with the gari and poisoned them. The idea was put forward that it could have been rat poison.

"Somehow it got mixed with the gari?"
"Yes. There are cyanide-based rat poisons around. Unfortunately, the doctor didn't pursue the case further by trying to obtain food samples. I've analyzed thousands of gari samples. I've not found any that could contain a level of cyanide that could be hazardous. We do 200 samples a day—10,000 samples a year. Cyanide is a very violent poison and that's why people are concerned, and they should be. But the human body has learned to live with cyanide for a long time. and it has developed mechanisms to handle cyanide toxicity up to certain levels.. The journalists at the workshop got the message."

"What about simillar rumors in other countries?" I asked, remembering that a Mozambiquean delegation had brought up the subject during a Maputo seminar, claiming that "hundreds of thousands of people had suffered acute food poisoning due to the consumption of cassava containing a high level of cyanide."

Officials in Ghana once said they would no longer receive cassava material from IITA, because IITA was in Nigeria, and in Nigeria cassava killed people, Bokanga replied. "We ran a trial of IITA and Ghanaian varieties side by side. We ran cyanide tests and we found they were comparable.'' In fact, he said with a broad smile, "the higher ones were the ones from Ghana.

After that there was no problem. I went into some of the restaurants in Ghana where they serve cassava, and they don't process it as much as they do in Nigeria. They just boil it in water and eat it"

It's when it's not properly prepared that the trouble starts. It's happened that at an African wedding feast, the revelers, celebrating too well, made the mistake of eating uncooked cassava and died. "But that's rare," said Cooke. "Children are taught early on, that what you don't do is to dig up the immature roots and eat them."

But there are documented cases of poisoning where, for example, drought had caused famine, and the hungry, in their desperation, ate uncooked cassava. Or in other cases the whole process of preparing cassava properly was shortened or accelerated for commercial reasons. The man who has worked for years on these cases is Hans Rosling from Uppsala University in Sweden.

He was a medical officer in Mozambique in 1981 when there was an outbreak of epidemic spastic paraparesis-over 1,100 cases. It's a disease that cripples by damaging the nerve tracts of the spinal cord, causing a spastic paralysis of both legs. The victims can usually stand up, but need a stick and walk with a "scissor gait" a crossing of the knees. When they walk their muscles often jerk uncontrollably. In the worst cases, the arms are also affected, as well as sight and the ability to talk.

All the cases m Mozambique were in one area a drought stricken part of the northeastern province of Nampula. They ate a lot of cassava because it was the only crop to survive. And they ate it recylessly without even letting it dry in the sun for long periods. Although this is the least effective method of lowering the cyanide content, it was their normal way of making it safe. But they neglected to do it. Other experts repeatedly made the point that although cassava got the blame in Mozambique for the epidemic, thousands of people would have simply starved to death, including those who were crippled, if there had been no cassava to fill back on. - Another affliction, where the finger of accusation is pointed at poorly processed cassava, is the aggravation of goiter— although with sufficient iodine "the thyroid can withstand considerable cyanide exposure." Also there's simple acute poisoning, as in the case of the Nigerian gari, where vomiting and dizziness struck a few hours after a meal. Those cases were fatal, but usually the victim recovers in about 24 hours.

Rosling's conclusion after ten years, research into all this is that ''human diseases caused by the toxic effects of cyanide are rare in relation to the wide use of cassava as a staple food. It's also rare in relation to other public health problems-such as tuberculosis, diarrhea, and malnutrition."

Quick to Rot

The other "dark secret' about cassava is that it deteriorates very rapidly when it's out of the ground— blue and brown streaks appear on it A few kilometers from the roadside stall where I had tasted the snack, a tired-looking donkey, laden with cassava in sacks, was waiting outside a shack. Inside, a "middleman" was buying cassava from the farmers and then arranging its transport to markets not only in Cartagena, but also in Barranquilla and Santa Marta, the other large towns along the north Colombian coast Because of its quick deterioration, dealing in it means taking a risk. So he had to get it moving immediately. Fresh cassava must get to the consumer within one to two days after harvest, and eaten in less than a week.

"When was this cassava taken out of the ground?"
"It was harvested yesterday," he said, "and it'll go to market this afternoon. It'll be sold early tomorrow morning"
"That's the normal number of hours?"
"Yes. I have people who travel with it, to sell it at the best markets. There are central markets in the big cities. There'll be different buyers there. From there, it may go to supermarkets or small shops who buy from there."

Scientists who study this "postharvest technology" have to think up ways of getting around this weakness. One answer to prolong its life is to pack the cassava in polyethylene bags, keeping them in a hot, moist environment, and adding a chemical to stop fungal rotting, explained Christopher Wheatley, one of CIAT's experts in this area.

"It'll keep in bags for about two weeks and then the eating quality declines," he said. But that's expensive. Another way, even more costly, is to freeze it "Freezing is used for exporting to the U.S. and Europe mainly for the immigrant communities there. You also find frozen cassava in supermarkets in Colombia and Brazil, about four to Six times the price of the fresh food. There's a small market for it among high-income groups who are prepared to pay for convenience foods."

A radical way to solve the problem would be to block the biochemical pathways that cause deteration after harvesting, Wheatley said, so allowing a two-week storage period.

"You are trying to breed that into cassava?"
"Exactly. Somehow to selectively block some of these specific biochemical pathways that cause deterioration, but in such a way that we're not interfering with any beneficial effects these pathways might have in a living plant"
"How far are you down that road?''
"We need a lot more basic biochemistry."
"Are you optimistic?"
"We're probably talking ten years plus."

Those Useful Leaves

Those critics who don't admire cassava, after enphashe cyanide and calling attention to its rapid deterioration, then say that it has no protein. But, yet again, the cassava has an answer—its leaves are full of protein and the leaves are edible.

A scientist from Sierra Leone told me that there they eat the leaves every day. They sometimes make a cassava leaf sauce and pour it on rice. They also do that in the Gambia and in Guinea. "The leaves are as important as the roots. Its very tasty, like spinach."

But what happens if the leaves are tainted with a disease, such as cassava mosaic disease? Some people, said H. W. Rossel, a virologist, actually like mosaic disease in their leaves because they say it gives a better taste: "It's apparently sweeter.”

"Isn't it dangerous?"
"No. The way they cook it makes it safe."

Cassava varieties are now developed to be resistant to diseases such as cassava mosaic, spread by the whitefly, which, as the name suggests, produces a mosaic of unsightly patches. New stains are also resistant to bacterial blight, which leaves a stems bare and which are then, again very aptly, called "candlesticks."

In his scremhouse in Ibadan, Rossel pointed to some deformed and distorted plants. "This is mosaic," he said, adding that it had to be put in perspective. "I'm not saying that mosaic isn't important," he repeated again and agains. "It is. It's everywhere." But, he went on, "there's a great deal of adaptation and tolerance, like cold and flu with us. If it's in every plant, the farmers will consider it a normal feature, and won't even recognize it as a disease. And that's the situation for cassava mosaic in Africa. Farmers don't see it as a disease. It's not something that bothers them. And the reason for that is supple. It means only about a 15 percent yield reduction. It's not devastating. It's not overriding."