by Chandra Arulpragasam

When I undertook a sociological survey, at the age of 23 years, among the Veddas of Wellassa-Bintenne in Ceylon in 1950/51, I came to understand the role of cassava (manioc) in the lives of the poor. Although the Veddas were mainly hunters/gatherers at that time, their real food security came from their chenas (swidden fields): and their key crop for food security was manioc (cassava). Since no money was used in the jungle and with no means to repay the Veddas for their hospitality, I would extract, in a miserly manner, only one tuber from a cassava plant, which would have to last me the whole day, until I reached the next Vedda hamlet by nightfall.

A Food Store in the Ground

But this set me thinking. First, the cassava was grown on every chena and was the only crop left standing when all others had failed: hence, it was their fail-safe crop, a key to their food security. Secondly I was cutting only one tuber from the plant, which usually has 3-4 tubers, so as not to deprive the Veddas of their food supply. This meant that the cassava plant was almost like a refrigerator in the ground. Unlike other foods, it could be eaten in installments, without spoilage over time. Whereas rice when harvested causes a glut in the market thereby reducing its price, cassava, on the other hand, can be left in the ground for 12 -17 months till the price is right.

A ‘Fail-Safe Crop’ in Drought and Flood

On an FAO Nutrition Mission to Sri Lanka during the severe drought of 1970-74, I found myself on the bed of a bone-dry village tank (reservoir) in the Dry Zone, with a couple of emaciated villagers from the jungle. I asked them how they had managed to survive through the ongoing drought. One of them simply produced a small stick tucked into his G-string, and uttered only one word: ‘manioca’. Checking the statistics for all of Asia, I found that whereas the output of all other crops had declined precipitously in drought and flood years, the acreage and total output of cassava had increased exponentially in those years. In other words, the farmers knew what they had to do in case of drought or flood: they planted more cassava!

Cassava Yields and Output

Looking into yields, although this was none of my business in FAO, I found to my astonishment (in 1971) that cassava out-yielded rice, wheat and maize in tons per ha by over 10 times over a 10 year period. Since cassava remained in the ground for a longer period than rice, and also because it had a greater moisture content than rice, I had to discount the cassava yield for these two factors. But I still found that cassava out- yielded rice or any other cereal by over three times.

Still the results were surprising, especially considering the fact that rice is grown on the best lands and is usually supported by expensive irrigation. Rice also received agricultural credit, fertilizer, pesticide subsidies and marketing support, as well as the undivided attention of agricultural research, agricultural extension and advisory services. In contrast, cassava was usually grown on neglected high land and received none of the above. Nor did it benefit from either agricultural research or extension. Meanwhile, the international agricultural agencies that were meant to serve the majority of farmers of the developing world, who were mainly subsistence farmers, did not pay any attention to this crop. Why, for example, had nobody looked for higher-yielding varieties of cassava, as they did for rice?

In the meantime, total rice yields had shot up due to the high-yielding varieties and double/triple cropping. Cassava yielded around five metric tons per ha on marginal lands in 1990, whereas yields were expected to reach 13 tons per ha by the year 2000, even without fertilizer or irrigation. As against this, rice yields seem to be leveling off at around seven tons per ha under irrigation, even with the higher-yielding varieties and even with double and triple cropping. But this is like comparing apples and oranges, since rice is usually grown on the best irrigated lowlands, while cassava is relegated to high, marginal and fallow lands, known for their poor soil fertility. Moreover, whereas much labour and expense is lavished on double/triple cropping of rice, cassava grows quietly under the ground without much care, providing much more calories over the same period, on the worst land, through drought or flood.

As for output, in the years 1969-1983, the total production of cassava actually doubled. This was achieved by expanding the acreage planted to cassava, passing from high lands to marginal and fallow lands with poor and poorer soils. This doubling of production was achieved by farmers acting on their own, with hardly any notice by the big international agencies supposed to be concerned with agriculture! Meanwhile, the latest studies (2010) show that fertilizers and pesticides are now being applied to cassava too, so that yields on selected plots have more than doubled.

Although I was not an agronomist and cassava was none of my business, I managed to worm a small piece into the chapter for Asia in FAO’s most prestigious journal (around 1972), setting out the case for cassava. But it did not have any effect, since cassava continued to be dismissed by the top agronomists as ‘merely a subsistence crop’ – although most farmers in the developing world depend on subsistence crops! When I led an agricultural policy mission to Indonesia in 1981, I found that in FAO’s main Agricultural Research Project, all six of FAO’s highly trained researchers were researching every other crop - except cassava. And this despite the fact that it was the third largest food crop in Indonesia, consumed daily by millions of its people!

Food Security: Cassava the Cinderella

of the Poor

This brings me to the importance of cassava and other tubers for small farmers. Despite my article of 1972 and my agricultural policy recommendations for Indonesia in 1981, all of which were ignored by FAO, Mr. Maurice Strong came out with an article entitled, ‘Cassava: The Cinderella of the Poor’, which I have borrowed as the title for this article. The decision to ignore cassava seemed to come from four built-in biases in the agricultural establishment.

First, cassava was cultivated mainly by small and marginal farmers – and it was not worth wasting time on such small and ‘uneconomic’ farms1. Secondly, cassava was usually not eaten in the western developed countries, whose scientists happen to determine the priorities for agricultural research in the developing countries. Thirdly it was consumed mainly by the poor, even though by millions of them, being ignored by reformers despite their new found zeal for poverty alleviation! Fourthly, since rice is a preferred food, the demand for cassava is likely decrease as the poor get rid of their poverty – which, however, is still a long way away.

In Asia in the 1990s, given the preference for rice and its ready availability, the area under cassava declined slightly. On the other hand, the acreage under roots and tubers (including cassava) in Sub-Saharan Africa rose by 70 percent in the 16 years between 1980 and 1996. Meanwhile, its demand as animal feed and as inputs for consumer industries in the developed countries keeps growing, while land-surplus countries such as Thailand and Brazil are increasingly growing it as a commercial crop for export.

Nutritional and Agronomic Concerns

From a nutritional point of view, calories are the most important to prevent hunger and to provide energy - the main concerns of the poor. Cassava provides twice the number of calories as potato, while also providing the main calorie source for over 300 million people in the developing world. It would obviously have to be supplemented by an adequate intake of protein from vegetable or animal sources. Cassava also provides a good source of Vitamins A and K, especially in its young leaves.

From an agronomic point of view, cassava is said to deplete the soil of its nutrients - which could be a problem for small farmers who have to plant this crop repeatedly on the same land. However, as verified from agronomists, proper land preparation and fertilization with nitrogenous green manure could rehabilitate the soil, so that cassava could be grown on the same land year after year.

My Cassava Swansong

I come finally to the end of my career in FAO, which oddly enough, had something to do with cassava. Because of a devastating drought in the early 1980s in Sub-Saharan Africa, the Director-General of FAO appointed a high-powered Task Force of FAOs’ top Technical Division Directors to make suggestions for immediate drought relief and longer-term drought prevention. I was suddenly instructed (five minutes before the meeting!) to attend it on behalf of my boss. Having had no time to read the report, I scampered over its 80 odd pages during the meeting while the others droned on. The main conclusion was that all crops in Africa had failed, while the African farmers’ practices were poor. But I thought to myself: surely the farmers would have switched to cassava or other root crops during such a prolonged drought? But there was absolutely no mention of either cassava or root crops in the entire 80 page report! So I scrambled to the Appendix, which contained statistics of the acreage and output of all crops mentioned in the report, all of which had drastically declined. But the Appendix, by accident, had also included the next page from the statistical year book, which by absolute chance happened to show the acreage and output of cassava, roots and tubers. And what do you think it showed? While all other crops had failed the acreage and output of cassava, roots and tubers had increased by leaps and bounds - which is what had saved the continent from starvation! And the agriculturalists of FAO had neither realized nor noticed this before! And if they had noticed, would they have even bothered to ask why the ‘ignorant’ farmers had chosen to expand this crop during the drought years? I was frothing mad, because I had written all this more than 15 years ago in FAO’s own journals – and I was not even an agriculturist!

However, my intervention at this meeting seemed to have a salutary effect: for the report was entirely re-written and presented to the FAO Committee on Agriculture with the new title, ‘Roots and Tubers’ around 1986. It must also be said to the credit of FAO that in the year 2000, it introduced ‘The Global Cassava Development Strategy and Implementation Plan’, although it was almost 30 years after I had written it up in an FAO journal. But for me, it all started in 1951, with my stingily digging up one cassava root from the Veddas’ frugal food store in the jungles of Bintenne!


It so happened that I developed a cancerous tumour in my right lung at the age of 81 years. I learned from a friend of mine, a doctor in Sri Lanka, that cassava offered a cure for cancer – which was confirmed by the research of a pioneering Filipino oncologist. I adopted the latter’s cassava protocol – and within 10 months I was cured of my cancer! Since I had also used another alternative therapy, I cannot be sure that it was the cassava that actually cured me, or both together. However, I really believe that I owe more to cassava than the story related above.

Excerpted from Fallen Leaves, a memoir of the writer launched recently in Colombo

1 It has been conclusively proved by studies in all developing regions that the smaller farm has a higher yield per acre/ha than the larger, best-managed farms, making the small farm the most economic in terms of total factor productivity – the best measure of productivity. In Sri Lanka, even the small tea and rubber holdings have been proved to have higher yields than the best large estates.


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