You may have never heard of the cassava plant, which is also called a yuca or manioc plant, but it one of the world’s most important sources of carbohydrates. According to Wikipedia, “cassava is the third largest source of carbohydrates for human food in the world.” The cassava is a woody shrub native to South America and West Africa, but its cultivation has spread beyond its natural habitats. Cassava is now extensively cultivated as an annual crop prized for its edible starchy tuberous root. That is why analysts are watching a pending disaster that has hit crops in East Africa [“Virus Ravages Cassava Plants in Africa,” by Donald G. McNeil, Jr., New York Times, 1 June 2010]. The culprit is a “damaging virus named brown streak, for the marks it leaves on stems.” McNeil reports that the virus is attacking “Variant No. 2961, the only local strain bred to resist cassava mosaic virus, a disease that caused a major African famine in the 1920s.” He continues:
“Brown streak, is now ravaging cassava crops in a great swath around Lake Victoria, threatening millions of East Africans who grow the tuber as their staple food. Although it has been seen on coastal farms for 70 years, a mutant version emerged in Africa’s interior in 2004, ‘and there has been explosive, pandemic-style spread since then,’ said Claude M. Fauquet, director of cassava research at the Donald Danforth Plant Science Center in St. Louis. ‘The speed is just unprecedented, and the farmers are really desperate.’ Two years ago, the Bill and Melinda Gates Foundation convened cassava experts and realized that brown streak ‘was alarming quite a few people,’ said Lawrence Kent, an agriculture program officer at the foundation. It has given $27 million in grants to aid agencies and plant scientists fighting the disease.”
Because cassava is widely cultivated around the globe, the spread of the brown streak virus could generate a world-wide crisis. McNeil continues:
“After rice and wheat, cassava is the world’s third-largest source of calories. Under many names, including manioc, tapioca and yuca, it is eaten by 800 million people in Africa, South America and Asia. The danger has been likened to that of Phytophthora infestans, the blight that struck European potatoes in the 1840s, setting off a famine that killed perhaps a million people in Ireland and forced even more to emigrate. That event changed the history of all English-speaking countries. Compared with amber waves of grain or the blond tresses of a field of ripe corn, cassava is an inglorious workhorse of a crop, a few spindly red stems sprouting from a clutch of brown tubers. It is filling but not very nutritious; it even contains trace amounts of cyanide, which must be removed by grinding and fermenting. But subsistence farmers depend on it because it’s ‘very drought-tolerant and very bad-management-tolerant,’ said Edward Charles, a team leader for the Great Lakes Cassava Initiative, a six-country consortium based in Kenya and supported by the Gates Foundation. For example, he said, even when farmers are too weak from malaria to weed, their crops survive. Also, the tubers can be left underground for up to three years, so if drought kills a corn or bean crop, the farmer’s family can still fend off starvation. But the plant falls prey to more than 20 pests and diseases.”
The real concern, McNeil reports, is that “brown streak will cross the Congo Basin to Nigeria, the world’s biggest grower.” The threat is real “because farmers sell cuttings to one another and border controls are nonexistent or can be evaded with bribes.” So although a global threat exists, for now, the spread of the brown streak virus across the African continent is the immediate concern. McNeil continues:
“Dr. Fauquet is optimistic it will not cross the ocean into Thailand, Brazil, Indonesia or China because there is no world trade in the cuttings and few direct flights to Asia or South America. (Whiteflies, which are thought to spread the virus, have been known to stow aboard planes.) However, he noted, mosaic virus did spread to India from Africa somehow. And Dai Peters, the Cassava Initiative’s director, noted that a mealybug that damages Brazilian cassavas has leapfrogged the globe to infect Thai fields, too. Even if the brown streak virus is contained in Africa, Dr. Fauquet said, donors may eventually be forced to spend billions of dollars on food aid to prevent starving populations from going on the move, which could set off ethnic fighting.”
Despite on-going research, “there is no cassava strain in Africa immune to brown streak.” In order to buy time to find a more permanent solution, farmers are being taught “to recognize diseased crops. When they discover their crops are infected, they are being asked to burn them. They are then provided “clean cuttings so they can get one or two harvests before the virus strikes again.” East Africa is familiar with virus-generated food crises. McNeil explains that East Africa is just getting the upper hand on banana wilt, “another virus that attacked a different East African staple food.” McNeil describes how researchers were able to gain the upper hand.
“In that case, the solution was relatively simple, said Chris A. Omongo, an entomologist at the National Crops Resources Research Institute in Namulonge, Uganda. Since bees and dirt spread the virus, farmers were taught to nip the purple male flower buds off each stalk and to clean their tools and boots before entering their banana patches. (The virus was jokingly called ‘banana AIDS,’ because it, too, spread along the Uganda-Tanzania highways and rivers. Banana beer was shipped in jerry cans with the fat purple flowers used as stoppers.)”
McNeil reports that “some wild and some foreign cassava strains … appear resistant to brown streak.” Such plants could provide a leg up to researchers seeking a solution to the disease, but they can’t simply be used as replacement crops because “they lack the taste and consistency that Africans like.”
Fortunately, a virus is not the root cause of the food security challenge facing Mongolia — that distinction belongs to an extremely harsh winter [“Mongolia counts carcasses after harsh winter,” by Charles Hutzler, Washington Post, 1 June 2010]. Hutzler reports, “More than 8.2 million animals, nearly a fifth of all livestock in Mongolia, have died in a winter of snow, cold and gales so severe Mongolians have a special term for it – ‘dzud.'” This most recent dzud broke the 1944 record when almost 7 million head of livestock lost in a winter. “This dzud started with a drought last summer. When October rains came and froze, the ice was followed by snow, sealing the stunted grass away from the animals. Temperatures plummeted to 40 below zero and colder. In many places, animals started dying in February and then kept dying.” Hutzler continues:
“The loss of so much livestock is devastating in Mongolia, a poor, landlocked country the size of Alaska. A third of its 2.7 million people are herders, wealth is measured by the hoof and livestock outnumber people 15-to-1. ‘For many herders, livestock is their main source of income. It’s their business. It’s what they do. That’s why the loss the herders are experiencing is the same as when a company or a bank goes bankrupt,’ said Purev Zagarzusem, governor of Uyanga, an administrative district and one of the worst-hit areas. ‘Other countries have tsunamis or earthquakes, for example, and people lose their lives and possessions. In Mongolia a dzud is a disaster on a similar scale.’ At a time when green shoots of grass sprout from the brown earth and herds should be migrating from winter camps to summer pastures, the animals are too weak to feed and travel. More are dying in sporadic snow squalls and high winds.”
This latest dzud is not only threatening food shortages in Mongolia it is threatening a way of life. Hutzler continues:
“This dzud is raising uncomfortable questions about the herders’ way of life, as integral to the Mongolian identity as Genghis Khan, whose image graces currency notes and vodka bottles. The constitution enshrines livestock as protected national wealth. Herders form a powerful constituency; parliament rescinded a head tax on livestock to curry favor with them. The government, in a report last year, identified the unfenced grasslands and the herds that roam there as acutely vulnerable to climate change, citing more frequent droughts and harsh dzud winters.”
Herders bear some of the responsibility for the high numbers of animals that died this past winter. Hutzler explains:
“Since Mongolia dumped the planned economy and its Soviet client-state status for free markets 20 years ago, livestock numbers have more than doubled, to 42 million head. Much of the increase is in goats valued for cashmere, who eat voraciously, damaging the roots of grasses and other plants that anchor the soil and prevent the pasture from turning to desert. While the government wants to move herders into other lines of work and decrease herds, an uncontrolled exodus from the steppe is already under way. After three harsh winters a decade ago, more than 70,000 herders ended up in Ulan Bator, swelling the shanty town fringes of the capital and mainly living on government handouts. The flow is expected to accelerate if the aftermath of the latest dzud is not controlled.”
With over 8 million carcasses littering the landscape, burying them is a top priority. Rotting carcasses can spread diseases and affect the water supply. A contaminated water supply “would be a huge catastrophe.” Although there is not a global food shortage [“Agriculture: Bumper harvests bring stability,” by Jack Farchy, Financial Times, 1 June 2010], it could be rough for people in Mongolia and parts of Africa. Niger, Chad, and Nigeria all face looming food shortages [“Millions face hunger in arid belt of Africa,” by Jon Gambrell, Associated Press, 28 May 2010]. Some ten million people in the Sahel, a band of semiarid land stretching across Africa south of the Sahara, are at risk of facing starvation this summer. A combination of an efficient globalized supply chain and local production is essential to help create food security around the globe (see my post entitled Food Security: Globalization versus Self-Sufficiency). As I have noted in previous posts about food security, several factors are going to guarantee that food security remains in the news for decades to come. Those factors include a rising global population, water scarcity, climate change, and the emergence of crop diseases and insects that display tolerances to old solutions. Recently analysts have predicted that “food commodity prices will increase more than previously expected in the next decade because of rising energy prices and developing countries’ rapid growth, … worsening the outlook for global food security” [“Steep price rises spark fears over global food security,” by Javier Blas, Financial Times, 16 June 2010]. With over a billion people now suffering from chronic hunger, you can expect persistent attention being given to food security around the globe.