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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


Cassava (also known as tapioca, yuca, or manioc) is not exactly a household word in the capitals from which the World Bank draws the bulk of its funds. For millions of the world's poor, however, it represents the difference between hunger and sustenance.

The world's ninth highest source of calories, and the fourth highest in the tropics (behind rice, sugar cane, and maize), it is the "root of life" across Africa, Asia, and Latin America. In Africa alone, cassava is the staple food of over 200 million people.

Nevertheless, cassava is an "orphan commodity" (like coarse grains. plantain, pulses, and tropical vegetables) that would not normally enter the research agendas of advanced public or private sector institutional.

So, the fascinating story of cassava research, which is the central theme of this essay, continues to unfold only because agricultural research has been deliberately used in the front line of the world's fight against poverty. That deployment was achieved by the Consultative Group on International Agricultural Research (CGIAR) and its network of international centers of excellence.

From its founding in 1971, the CGlAR has functioned as a guarantor to the world's poor, ensuring that international scientific capacity seeks solutions to some of their most pressing problems. As a result, food requirements have been secured where scarcity and famine were common, and many societies have experienced the broad range of benefits generated by agricultural development. The "quiet revolutionaries" of that endeavor include peasant farmers, policy makers, scientists, and donors. The Bank continues to provide perceptive and generous leadership.

But only the battles have been won. The war goes on. Retreat or defeat will increase human suffering and domestic as well as international turbulence. Poverty and deprivation remain formidable foes. Food productivity has to be scientifically increased to meet the needs of a growing human family while, simultaneously, the natural resources on which food productivity depends are protected and preserved. Agriculture has to continue its role as an engine of change. In this situation, the quiet revolutionaries have only one option. They must remain engaged.

W. David Hopper

Atart but true was pinned on wall of entomologist Tony Bellotti's office .It was a paraphrase of a quote by that iconoclastic and curmudgeonly American journalist. H. L Mencken: "For every problem, there's a solution that is simple, direct, and wrong." It was good to know that journalists could sometimes be of use to scientists.

Bellotti, a former New Yorker, is a longtime, contented resident of Colombia He is also one of the many players in an epic drama: the great defeat of the cassava mealybug in Africa It's being called the classic biological control victory, and its teams of scientists are deservedly being garlanded with citadons, compliments, and occasionaIly checks.

Cassava, which is also known as yuca, manioc, or tapioca, is the staple food of 200 million Africans. The mealybug was systematically destroying it across great tracts of the cassava belt, which stretches from Senegal in the west to Mozambique in the southeast. In some areas 80 percent of the crop was lost at a cost of billions of dollars.

This starchy root crop, found almost entirely within the tropics, resists drought, can thrive in poor soils, can be left in the ground for two to three years until it's needed, and can survive hurricanes and plagues of locusts. But m the 1970s, African farmers, taught by their ancestors or colonial officers always to grow cassava as an insurance against famine because of this legendary toughness, were beginning to give up on it. And the experts were beginning to wonder if the "indestructible", cassava had at last met its match.

First identified in Zaire in 1973, the mealybug fed on the fluid in the cassava leaves, making them look a bit like cabbages. The plants simply collapsed. Nothing stopped the pest's steady advance. The farmers couldn't afford pesticides insect didn't seem to have a "natural enemy" parasite or predator that attacked it and kept it under control. Agricultural scientists had to come up with an answer. So what was to become the largest classical biological control program in the world was set up in Nigeria to begin the search.

The mealybug's introduction into Africa was recent—probably in the late 1960s. In earlier centuries it wouldn't have survived the long boat journeys from wherever its origin was, but with jet travel it could easily have arrived in Africa, lurking perhaps on some infected cassava cuttings. But where exactly did it come from? It had never been reported from anywhere outside Africa. Where should the scientific detectives start looking?