A Danger to the Global Wheat Supply: Ug99

Like all plants, wheat is affected by certain insect pests as well as certain plant diseases. Every farmer wages a constant battle against plant pests and diseases. Some years are worse than others. Some plant diseases are worse than others. A lot worse.

In the early 1940′s, a type of plant disease called “stem rust” — so called because it looks like the plant stem is rusting — was ravaging the wheat crops in Mexico. The particular variety of stem rust was called P. graminis. It was a scourge on the wheat fields of Mexico. Yields fell to half of their former abundance. People went hungry.

Enter Norman Borlaug, a young agricultural researcher newly-funded by the Rockefeller Foundation. He and his research team bred genes for resistance to stem rust, from rye into wheat. The most useful of these stem rust resistance genes was Sr31. The improved wheat successfully fended off P. graminis, saving lives:

“The creation of rust-resistant wheat was one of the cornerstone achievements of Borlaug’s Green Revolution, which produced multiple disease-proof, high-yielding crops capable of feeding once-hungry populations. By 1970, stem rust was no longer a threat to nations that relied on wheat as a dietary mainstay. It is impossible to calculate how many lives Sr31 and other disease-resistance genes saved, but hundreds of millions would be a fair guess.” (Wired.com)

It took 30 years, from 1940 to 1970 for the world to overcome this particular plant disease. Borlaug eventually received the Nobel Prize for his work initiating the Green Revolution.

That was then; this is now. A new version of stem rust has begun to spread through the wheat fields of the world. This variety is impervious to the stem rust resistance genes of the past. This scourge is called Ug99 because it was first identified in Uganda in the year 1999. Since then, it has spread throughout Africa, into the Middle East, and northward toward Europe, and eastward toward Russia and India. None of the commonly-grown cultivars of wheat are able to withstand this type of stem rust. Here is a map of its spread:

Can it cross an ocean and end up in the wheat fields of Canada or the Midwestern U.S.? Yes, it can. The prevalence of global shipping and travel means that any widespread pest or plant disease can, and eventually will, cross from one continent to another, even over oceans and vast distances. It is only a matter of time.

The U.N. is concerned: The U.N.’s Food and Agricultural Organization on Wheat Stem Rust – Ug99 and so is the USDA: USDA on Ug99. There are numerous projects around the world aimed at developing Ug99 resistant varieties of wheat. Resistant varieties have been and continue to be developed. Good.

Now here’s the problem.

The world agricultural system is more heavily dependent on wheat than ever before. The world planted 216,974,683 hectares of wheat in 2010 (FAOSTAT). (A hectare is 2.471 acres.) This yielded 650,881,002 metric tonnes of wheat. That’s 1,434,946,981,100 pounds of wheat (yes, 1.4 trillion lbs.). The world average yield for wheat is therefore 3000 kg/ha. How much wheat seed was needed in 2010 to plant 217 million hectares of land in order to grow 650 million metric tonnes of wheat? The FAO estimates the amount of wheat seed available (in 2009) to plant the 2010 world crop of wheat to be: 34,513,845 metric tonnes. That’s 76,090,003,454 lbs of wheat seed (76 billion pounds) needed to plant one year’s crop.

Wheat varieties resistant to Ug99 exist. But we don’t have nearly enough to plant 217 million hectares. We would need 34.5 million metric tonnes of wheat seed for the entire world harvest of wheat. As an interim measure, farmers could plant Ug99 resistant varieties only in areas that are threatened by this version of stem rust. But the amount of wheat seed needed is still immense. If only 1 of every 34 hectares of wheat (about 3%) is planted with a resistant variety, we would still need one million metric tonnes of wheat seed. Right now, wheat seed of resistant varieties only exists in research quantities: kilograms, not metric tonnes. One metric tonne is 1000 kg; one million metric tonnes is one billion kilograms.

So even with a best case scenario, in which there is ample money and cooperation from all parties involved, it would take years to obtain enough Ug99 resistant wheat seed for only a small portion of the wheat fields of the world. In the meantime, the wheat harvest could be devastated. Wheat provides about 20% of the world’s total agricultural production, in terms of caloric content of the food. It is one of the top staple crops. (The others are: maize, rice, soy, and barley.) If the wheat crop is devastated, then every other food will be in higher demand. Food prices would rise across the board. The world is so heavily dependent on just a few major staple crops, that any major widespread problem with just one of those crops will cause worldwide problems with agriculture and food.

This type of disaster is not the end of the world as we know it (TEOTWAWKI), but it is entirely within the realm of possibility. It is not just around the corner, but it could happen in our lifetime. Compared to other conceivable severe disasters, this is one of the more realistic. This is just one of many reasons why it is important to have stored food, as part of your emergency preparedness planning.

You might want to give this article from Wired.com a read: Red Menace: Stop the Ug99 Fungus Before Its Spores Bring Starvation

– Thoreau

Comments are closed.