Crop fungus threatens wheat harvests

A deadly airborne fungus could devastate wheat harvests in significant regions of central Asia and Africa, the Guardian reported, citing leading crop scientists. Because the disease specifically targets resistance genes in wheat, they said, 80% to 90% of all varieties grown in developing countries are susceptible to the fungus.


The scientists warned that the fungus Ug99 – first seen in Uganda in 1999 – is a new variety of “stem rust”. That crop disease spread from Africa to Iran and has blighted wheat production in many parts of the world for thousands of years. The fungus was thought to have largely disappeared in recent decades, when disease-resistant wheat varieties were developed and widely planted around the world.

Scientists meeting in Mexico to exchange information on Ug99 say the fungus is particularly dangerous because it can infect crops quickly. It releases vast clouds of invisible spores that can be carried by the wind for hundreds of kilometres. Global wind models suggest the disease may next spread into Pakistan, Afghanistan and India.

“This thing has immense potential for social and human destruction,” said Norman Borlaug, the Nobel Prize-winning scientist credited with helping India and other countries avoid famines in the 1960s by developing new crop strains. “It is capable of severely damaging virtually all of the world’s commercial bread wheat.” Rick Ward, coordinator of the Durable Rust Resistance in Wheat project based at Cornell University in the United States, saw potential for “a disaster of catastrophic proportions which will translate into widespread food insecurity and civil unrest”.

However, scientists also reported rapid progress in developing disease-resistant wheat varieties. Some are thought to be resistant to Ug99, as well as higher-yielding than current crop varieties.


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