Wheat Rust: An Emerging Problem In The Agro Field

Posted on August 23, 2010 in Environment

By Aashu Anshuman:

In 1961, India was on the verge of a mass famine. In that moment of crisis MS Swaminathan, the advisor to the Minister of Agriculture very suitably sought help from a certain Norman Borlaug (a.k.a the Father of Green Revolution). The government collaborated with the Ford Foundation and imported modified wheat seed from Borlaug’s own International Maize and Wheat Improvement Centre (CIMMYT). Thus began India’s Green Revolution and in a matter of a few years, India went on from being an importer to a major exporter of food grains.

Going further back, in 1943, Norman Borlaug discovered a gene — the famed Sr31 — which resisted Puccinia graminis, the most devastating form of wheat rust (a fungal disease that effects wheat,barley and rye stems, leaves and grains). This find, considered to be one of the greatest in human history, saved several million people across the world from malnourishment and eventual death. Stem rust was effectively defeated and farmers across the world heaved a collective sigh of relief. By the 1970s, it was believed to have been wiped off from the face of the earth.

Thereon, farmers, scientists and governments fell into a state of complacency. CIMMYT saw the budget of its global wheat programme cut by 40% in real terms since 1980. Today, only five institutions in the world are able to properly identify stem rust, and three of them do not accept foreign samples.

Fast forwarding to 1998, William Wagoire, a plant breeder and a pupil of Borlaug’s, was in south-western Uganda, when he came across something he didn’t believe existed anymore. But actually, the variety of stem rust Wagoire had come across had lived on in a remote corner of Africa’s Great lakes and had been evolving the whole time. This new variant, called the Ug99 (Ug for Uganda, the country of its discovery; 99 for the year it was confirmed), had mutated to conquer the mighty Sr31. As Borlaug had once said, “The Rust’ never slept.”

A few thousand miles away and years later in 2002, another pathogen race, again a form of rust, had emerged in South Asia. The Stripe Rust also called the Yellow Rust (or Yr) had overcome the resistant gene in wheat and turned out to be way more dangerous than was ever expected. ICARDA quickly sprung into action to carry out extensive research to fight this new, stronger and grossly underestimated sibling of stem rust. Luckily, the further spread of Yr was restricted due to unfavourable weather. But it returned in 2009, when it, capable of destroying 100 percent of the yield according to the scientists, affected as much as 80 percent of the fields in certain key wheat producers like Syria. Other affected countries include Afghanistan, Algeria and Tunisia.

Meanwhile Puccinia graminis continued its spread. Spores of rust, billions of them, are carried from one field to another by wind. But they can take much larger leaps. In 2007, rust jumped the Red Sea, probably as a result of Cyclone Gonu and entered Yemen. From there it spread to the Mongolian steppe and into Iran, where luckily droughts held its spread for some time. Back in Africa, Ug99 and its variants spread northwards into Sudan and reached as far south as South Africa, a major wheat producer. Kenya, where it spread violently in less than a year, saw nearly 80 percent of its wheat crop destroyed by stem rust in 2007. By 2009, stem rust had already affected 8 major wheat producing nations.

In a world in which 800 million people are chronically undernourished, anything that reduces the food supply has potential for tragedy. The pathogen has now come knocking on the doors of China and India, which among the world’s largest wheat producers and exporters. Recently, four new mutations of Ug99 have overcome existing sources of genetic resistance developed to safeguard the world’s wheat crop. Leading wheat experts have said that these new variants are even more deadly and are evolving even more quickly.

But the future is not all bleak. Scientists across the world have been brought together by the Borlaug Global Rust Initiative to fight this new and immensely powerful enemy. CIMMYT and ICARDA have shown agility in developing new species of wheat which are resistant these new variants of rust. India has developed its own rust-resistant variety of seed. These new varieties of wheat, which bear nearly no direct extra cost, are being taken to the markets to replace the weaker ones. Even privately run organisations like the Gates Foundation have come up with monetary help whenever the researchers have needed it.

Experts believe that 80-90 percent of the world’s current wheat produce is susceptible to rust but the farmers should be hopeful because this time around, everybody is acting before the epidemic and not during one. The challenge is huge and even scary but it looks like the good side has finally started to come out as victorious.

The writer is a Correspondent of Youth Ki Awaaz. He is also a student in the Department of Ceramic Engineering at the Institute of Technology, Banaras Hindu University. A Python enthusiast, an avid reader, a budding technology entrepreneur and a huge cricket fan, he appreciate the Red Hot Chili Peppers and Kailash Kher.