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Norman Borlaug is a hero. Like the warrior Beowulf, subject of the Old English epic poem, Borlaug slew a monster, saved his world and lived to a ripe old age. Like Beowulf, this old warrior of science has had to climb back into armour to battle the rise of a new monster. And once again, the world is looking to him for salvation.
In 1970, Borlaug won the Nobel Peace Prize for saving hundreds of millions of people from starvation. The monster he slew was stem rust: a devastating fungus that has plagued the world's wheat fields since Roman times. He did it by breeding a slew of powerful new varieties of wheat that could defend themselves against the scourge.
Yields doubled and tripled, ushering the Green Revolution across Asia and Latin America and averting the impending starvation of millions. Suddenly, food was bountiful. That victory was achieved 50 years ago in Mexico. The wheats he bred protected much of the world from the rust monster.
But now stem rust has awoken from a long sleep and is again threatening the world's food supplies: a virulent new strain appeared in Uganda in 1999, and it is on the march across the planet. While humanity rested on its laurels, the fungus spread to Kenya, Ethiopia and Sudan, then jumped the Red Sea to Yemen. In 2007 it reached Iran. Now, like a cobra, it is poised to strike the major breadbasket of Asia – the Punjabi plains of Pakistan and India.
If it strikes, crop yields will crash and millions will go hungry. It could not come at a worse time: the world's food reserves are running low. Granary stocks worldwide once held enough to last 100 days; due to a combination of climate change hammering yields and the growing competition from biofuels, the global granary is now down to 30 days. It's part of the reason why grain prices spiked in early 2008, triggering food riots from Haiti to Bangladesh.
"It's a train wreck," says Thomas Lumpkin, the director-general of CIMMYT, or Centro Internacional de Mejoramiento de Maíz y Trigo (International Maize and Wheat Improvement Centre) in Mexico. Now add stem rust to this picture and it's not a slow-motion train wreck, but a nuclear bomb ticking in the background. A major outbreak in Asia could empty global granaries overnight.
WHEAT SUFFERS FROM many diseases, but stem rust is the most ruthless – it gorges on the sugars bound to the grain and then erupts on the stem in rusty pustules. These then explode into vast red spore clouds that spread their destructive force across continents and oceans. In the 1950s, stem rust halved wheat yields in many U.S. states. In the 1970s, it crossed the Indian Ocean from Africa to wipe A$300 million off Australia's wheat harvests.
But fundamentally it's back to the old Malthusian problem, first outlined in 1798 by the English scholar Thomas Robert Malthus: booming populations eventually overwhelm their food supplies and face starvation. Today, the rate of global population growth is rising faster than our ability to produce food. Take a look at wheat: the average annual yield increase is less than 1% but, according to Lumpkin, the world needs a 1.5% increase each year just to keep up with consumption.
We have been slowly descending again into the Malthusian scenario faced by India and Pakistan in the 1960s – so you would think the world would be rallying to the emergency. They haven't. Political leaders have forgotten the wisdom of Socrates: "No man qualifies as a statesman who is entirely ignorant of the problems of wheat."
When the stem rust monster awoke in Africa in 1999, few had any memory of its menace. Those who could battle the threat – the world's international agricultural research centres – are these days run by an army of threadbare foot soldiers relying on scatty intelligence and carrying minimal clout.
Their political masters and the global financers who trade in food had grown complacent in the years of plenty. Lumpkin told me, "As an agronomy professor at Washington State University, I taught about the glories of CIMMYT [where Borlaug fomented the Green Revolution]. When I arrived, I found ceilings that hadn't been changed for 50 years and broken-down equipment."
The warning cries of the world's agricultural scientists were ignored. So in 2005, Borlaug, the old knight, trumpeted the alarm and again rode into battle. He was 91 when he convened the Borlaug Global Rust Initiative, a gathering of the world's leading wheat experts from 40 countries, which met in Kenya.
There, he galvanised the disparate national and global agencies into a coalition of the willing. And he attracted US$26 million from the Bill & Melinda Gates Foundation to begin the Durable Rust Resistance in Wheat initiative – a global project co-ordinated by Cornell University in New York State to speed up the breeding of new resistant wheat varieties.
Borlaug is revered for many things: his skill as a wheat breeder, his pragmatic humanism, his unwavering focus on feeding the world, his internationalism. But not for his saintly disposition. A college wrestling champion, Borlaug is tough. His success in fomenting the Green Revolution was as much due to bull-headed determination as to his skills as a breeder. And he is fearless about wading into policy and politics. Which is just what this global battle needed.
IN MARCH 2009, Borlaug convened a second council of war in Mexico. Representatives of 200 organisations descended on Obregón City, and I joined them. Arriving by 25-seater plane from Los Angeles, the vastness of the desert below me was stupefying: it stretched for virtually the entire two-hour flight.
As we neared Obregón, the verdant patchwork quilt below came as a shock. The agricultural largesse is everywhere as you drive along the highway into town: giant grain elevator after giant grain elevator, vast cone-roofed grain silos, Corona breweries, bakeries, on and on. It's astonishing to think that what is today a national breadbasket and a global agricultural Mecca was a godforsaken patch of rust-ravaged farmland only 60 years earlier.
That's when Borlaug first visited the Yaqui Valley – the coastal plain the stretches from the Sierra Madre to the Sea of Cortez. Obregón is the main town. Borlaug was the chief pathologist of a project to help Mexico modernise agriculture and feed its people – a joint venture of the philanthropic Rockefeller Foundation and the Mexican government.
His first mission was to bring stem rust under control. Across the country, the cruel fungus was turning golden wheat fields into wastelands of blackened stalks and shrivelled grains.
His eventual victory relied on a combination of skill, steely determination and the hand of fortune – "Princess Serendip," as he called it. He protected the wheat the only way he could – by crossbreeding it to resistant varieties from around the world.
His instincts as a breeder told him that to protect wheat, he would need to do thousands of crosses to capture resistance genes. Not only was he trying to fortify wheat against stem rust, but also the troublesome leaf rusts which bring down yields by as much as a third. And of course there were plenty of other wheat diseases around such as Septoria and Fusarium.
Like a poker player, Borlaug was aiming for a perfect set, a royal flush of resistance genes. And like a poker player he was subject to the rules of chance. To increase those chances, he carried out a mind boggling 6,000 matings between different wheat varieties each year. That created tens of thousands of hopeful wheat progeny from which a few dozen were selected (see "A royal flush" on p52).
Through the sheer force of numbers and 'a feel' for the traits he was trying to capture, he succeeded in putting together a royal flush of rust-resistance genes. Plants such as Yaqui 50, bred in the Yaqui Valley in 1950, resisted stem rust for over 60 years.
Besides making wheat rust resistant, Borlaug also dwarfed his wheats. Yaqui 50, like all traditional wheats, reached to a man's shoulders. That was fine when the wheat was scrawny. But as fertiliser and water fattened the grain, the plants got top heavy and fell over. The solution was to make a stockier plant.
The Japanese are famed for their horticultural miniatures and wheat is no exception. A dwarf wheat known as Norin 10 provided the genes to dwarf Yaqui 50. The famous semi-dwarf wheats, such as Penjamo and Pitic, were born. They sucked up nutrients and because there was little stalk the ears grew even fatter. Yields doubled and tripled.
Then Borlaug hit upon an idea. He first visited the Yaqui Valley in 1946 out of curiosity. His own research station was near Mexico City, some 2,000 km south of the valley. He visited a model agricultural research station that had been set up in the valley in the 1930s; what he found was a station in shambles and the local wheat farmers defeated by rust.
Borlaug wanted to help them; he was an Iowa farm boy after all. But he also glimpsed a way to help himself. At his research centre in the highlands near Mexico City, they planted wheat in the spring and harvested in summer. But in the baking heat of the Yaqui Valley, they planted in autumn and harvested in spring.
Borlaug realised he could just 'shuttle' seed from one place to the next and get two crops per year. It would cut down the seven or eight years required for his massive breeding program by half.
Traditional wisdom was against him: seeds were thought to need a 'rest' and breeders were supposed to breed plants for one environment only. But Borlaug ploughed ahead with his idea – against major opposition. His boss and other experts in the Rockefeller management vetoed the plan. Borlaug quit. His boss relented.
Borlaug's intuition worked and delivered an unexpected dividend: not only did the 'shuttle' halve the normal breeding time, it produced truly international wheat. Seed that stayed on the shuttle had to be able to grow at two different altitudes, survive two different types of ecology and, remarkably, had to ignore the waxing and waning of the day length: at the Mexico City site, the days lengthened as the wheat matured while at Yaqui Valley the days shortened.
The Yaqui Valley shuttle provided for the future prosperity of Obregón. It also provided wheat that could be grown from Australia to Azerbaijan; that could foment a Green Revolution; and by freeing nations from food aid dependency, lay the foundations for building modern economies. As Borlaug told the meeting in Obregón, "The Yaqui Valley was the birth place of the Green Revolution." It was fitting for this war council to convene here.
THE HIGH YIELD offspring of Yaqui 50 were wildly successful, and as part of the Green Revolution, ended up ended dominating wheat fields around the world. But breeders never rest. They're always looking to improve wheat – to make it yield more, make it more pest resistant, more salt tolerant or produce better quality flour.
But every time they perform a cross to gain something new, they are also likely to lose something old. In this case, the thing they lost over time was the 'royal flush' that Borlaug had captured in the Mexican wheat.
Most breeders have relied on a single defensive gene against rust, known as Sr31. And that was just sweet temptation to a microbe. With its formidable mutagenic powers, it was only a matter of time before stem rust overwhelmed Sr31.
It was no surprise that it happened in East Africa. The rift valley countries of Uganda, Kenya and Ethiopia grow wheat year round – in the valleys in winter and up on the escarpment in summer. So rust gets year-round lodgings. And even if the wheat varieties being planted are unwelcoming, rust can always find a few wild relatives to hole up in. Because rust never sleeps in such a place, the chances of developing a new resistant strain are high.
What was a surprise was that wheat breeder William Wagoire even recognised the red pustules growing on wheat stems in a test plot in Uganda. His generation had never seen stem rust. Wagoire sent a sample to Zak Pretorius' lab at the University of the Free State in Bloemfontein, South Africa, who in 1999 confirmed that the pustules were indeed stem rust.
Most worryingly, he showed that this new strain, named Ug99 (for Uganda 1999), could overwhelm the main defence of much of the world's wheat: Sr31. Across vast tracts of the Punjabi plain in Pakistan and India, in Kazakhstan, China, Canada, America and Australia, wheat is a sitting duck for Ug99.
At Obregón, the coalition of the willing met to discuss the progress of the battle. The main plan is to defend the world's wheat by giving it back a royal flush of rust-resistance genes. They no longer have to do it the way Borlaug did: through brute force and feel. Today's breeders have a short cut: they can virtually peer into the seed to determine the gene sets it carries.
Genes come naturally tagged by stretches of a unique sequence of DNA letters, like a barcode, and modern DNA labs can read those barcodes in a matter of days. The breeder need only shave a snippet off the seed and send it off. If the reading shows it carries a winning combination of resistance genes, the breeder can plant what remains of the shaved seed. With these shortcut techniques, CIMMYT has bred wheat carrying new sets of rust-resistance genes.
They have been tested against Ug99 in the heavily infested test plots of Njoro, Kenya, and the winning strains distributed across the world as part of a travelling wheat nursery. Breeders in Kenya, Iran, Pakistan and India have selected the babies they liked best and are busily multiplying them. They expect to have enough seed to replace their susceptible fields within three years.
But the mood at Obregón was far from breezy. There was a sense of relief that the world was getting together at last, but there was also fear that something sinister was brewing, and that victory was far from certain.
The weak link in the defensive chain is getting the resistant new seed into the fields to farmers. Poor farmers in Pakistan and Kenya traditionally save their seed – they don't have the money to buy new seed varieties from the companies who will multiply the seed. And wealthier ones may be loathe to change varieties that, so far, are still providing handsomely.
In the U.S. for instance, "they would rather just spray fungicides", says Brian Steffenson, a plant pathologist at the University of Minnesota. But that's not a solution, he says. "Serious rust epidemics need heavy spraying, and that runs the risk of resistance to the chemicals. It's not easy to develop new fungicides." And it's certainly not a solution for the poor farmers who farm most of the land across Asia and Africa. They can't afford it.
ANOTHER SOURCE OF UNEASE is that there is a large blind spot when it comes to gathering intelligence about stem rust. After the severe U.S. rust epidemics of the 1950s, 'trap plots' were monitored across Africa to provide advance warning of stem rust. But as Jesse Dubin, a former associate director of CIMMYT pointed out, in the 1980s the funding to maintain them was cut.
Now the United Nations Food and Agriculture Organisation (FAO) is taking charge of rebuilding that surveillance, but monitoring millions of hectares of wheat fields across remote regions of Asia and Africa for rusty pustules on wheat stems is no easy task.
That's Keith Cressman's responsibility: his job is somewhat easier because he already runs the FAO's trans-boundary locust forecasting service. This involved training local people to monitor and report locust sightings – if there are locusts in Somalia, the FAO will warn the neighbouring Ethiopians. Some of these trainees will now also monitor stem rust.
But reporting stem rust takes much more skill than reporting locusts. It's not enough to train someone to detect rusty pustules on wheat stems, and equip them with a portable GPS and a mobile phone. Not all stem rusts are equal: some might be the plant's equivalent of an annoying cold; others have killer flu potential.
The rust detective would have to try and sort this out using a panel of 'canary' wheats: for instance wheats that carry the Sr31 gene. If the rust grows on Sr31 wheat, that's likely to be the killer variety.
Sounds simple, but it's not. As Rick Ward, project coordinator for the Durable Rust Resistance in Wheat at Cornell University told me, "reading the pustules is an art form". And false alarms can have devastating consequences for global food prices and availability. With jittery futures markets paying close attention to Ug99, there is the potential to send grain prices soaring, causing the catastrophic hoarding of grain.
The diagnosis of a brewing Ug99 epidemic requires the skills of an expert plant pathology lab. And there are precious few of them: India and South Africa have them, but won't accept foreign samples of stem rust. Neither will Australia's elite lab at the University of Sydney's Plant Breeding Institute in Cobbitty, New South Wales.
The only two places where the rust detectives can send their suspects is to the USA's Cereal Disease Laboratory at the University of Minnesota, in Saint Paul, or to Canada's Cereal Research Centre at Winnipeg. "That's pretty darn thin for a planet," says Ward.
These countries are so frightened of Ug99, the labs will only test the spores in the heart of winter when there is little chance they can escape the lab. So if a virulent new strain of Ug99 is brewing in Pakistan right now, researchers won't know for sure until the northern winter – which could be a whole year later.
The worst case scenario is that breeders may have already lost the arms race without knowing it: UG99 could have mutated to a form that will overwhelm the defences of seeds being multiplied. Ug99 is particularly shifty: it has already mutated once since it was detected in 1999: Kenya has a variety that resists both Sr31 and another key resistance gene, Sr24. The rust monster may be way ahead of the breeders.
"We're in a very dynamic phase. All of a sudden the pathogen adapted – we don't where it will end," says Cobus Le Roux, a researcher at South Africa's Small Grain Institute.
Only careful intelligence gathering can help the breeders stay ahead. "There's unquestionably a problem with analysing rust [strains]," says Robert Park, director of rust research at the University of Sydney's Plant Breeding Institute and leader of Tracking and Surveillance within the Durable Rust Resistance in Wheat – a project with the Borlaug Global Rust Initiative that is funded by the Gates foundation. One of Park's jobs is to help establish expert laboratories in the regions at risk – a goal that is about two years away.
Problem is, stem rust spreads like wildfire. If weather conditions are right (moisture and warmth) and if there is plenty of fuel (susceptible wheat), then the epidemic can rage out of control. "It's a roll of the dice," says Lumpkin.
FRAIL AND ONLY DAYS before his 95th birthday, Borlaug's focus is unshakable. At the press conference, he hammered the need for better surveillance of stem rust.
Another journalist said to me, "I have never met anyone so 'on message'." It's very much part of the Borlaug style, his marriage of science and humanism. And it's a message that continues to inspire those around him.
"A lot of us who go into agriculture want to do something to help humanity. Borlaug is the giant that we hope to emulate," Steffenson told me as we bussed along the road lined by granaries and criss-crossed by massive semi-trailers carrying grain.
It's not just academics Borlaug has inspired. At the opening session of the conference, Theodore Crosbie, vice-president of Global Plant Breeding at Monsanto, the American multinational agricultural biotechnology giant, told delegates about meeting Borlaug 35 years ago. He was a student at Iowa State University, and Borlaug challenged him, "Why don't you work on something that matters?"
"One conversation with Borlaug and you're a changed man," says Crosbie. Decades later, Crosbie was clearly chuffed to announce at Obregón that Monsanto was awarding US$10 million over five years to researchers in developing countries to improve wheat and rice yields.
Borlaug's parting message to delegates was a refrain of his opening one: a plea for reviving the internationalism of agriculture. In his opening address, he recalled how years back, the farmers and scientists of the Yaqui Valley welcomed people of all languages, races and colours, as they came there to learn the ways of wheat. Faltering with emotion, he emphasised "that was the lesson they learned here".
One of those was Abdul Mujeeb Kazi, who became one of CIMMYT's most famous wheat breeders and is now a project director at the National Wheat Program in Islamabad, Pakistan.
At his parting speech Borlaug asked, "Why did it take so long [this time] to get good international co-operation?" Perhaps, as Kazi put it, "Ug99 may be a blessing in disguise – it has brought the international community together."
"Our tasks are enormous, but do-able," Borlaug said later. "So let's get on with the job. There is no room for complacency."
Elizabeth Finkel, a former biochemist, is a celebrated Melbourne-based science writer and a contributing editor of Cosmos. This story was a finalist for the 2010 Eureka Prize for Science Journalism.
