The diet of more than 800 million people revolves around neither wheat, nor corn, nor rice. Instead in many countries the main staple consists of the starchy roots of a plant variously called cassava, tapioca, manioc or yuca (not to be confused with the succulent plant yucca). Indeed, cassava contributes more to the world’s calorie budget than any other food except rice and wheat, which makes it a virtually irreplaceable resource against hunger. Throughout the tropics, families typically cultivate it for their own consumption on small parcels of land, although in Asia and in parts of Latin America the plant is also grown commercially for use in animal feed and starch-based products. The root’s nutritional value, however, is poor: it contains little protein, vitamins or other nutrients such as iron. Better varieties of cassava could thus effectively alleviate malnutrition in much of the developing world.
Because of that promise, the two of us and our colleagues at the University of Brasilia and others are devoted to creating hardier, more productive and more nutritious varieties and making them widely available to farmers in developing countries. Our team focuses largely on applying traditional breeding techniques to form hybrids between cassava and its wild relatives, taking advantage of traits that have evolved in the wild plants over millions of years. This approach is less costly than genetic engineering and does not raise the safety concerns that make some people wary of genetically modified crops. Meanwhile researchers and nonprofit organizations in the developed world have begun to take an interest and have produced genetically modified cassava varieties for the same purposes. The recent completion of a draft genome sequencing of cassava may open the way to further improvements.