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Wheat Rust Threatening Crops in Africa, Asia and Mideast

  • Joe DeCapua

Wheat rust in Kenya

Wheat rust in Kenya

Scientists met this week to discuss an aggressive new strain of wheat rust disease that has the potential to devastate crops in many parts of the world.

It’s been found in Ethiopia, Kenya, Morocco, Syria, Turkey, Iran and Uzbekistan. A meeting has just concluded in Aleppo, Syria, where experts made recommendations to stop the spread of the disease and ensure the health of future crops.

The danger

“Yellow rust or stripe rust, as it is known in the U.S., is considered to be the most important economic disease on wheat in, I would say, West Asia, Central Asia and North Africa,” said Mahmoud Solh, the director-general of ICARDA, the International Center for Agricultural Research in the Dry Areas.

Recently, much attention has centered on a rust strain called UG99, which originated in Uganda and spread to Kenya, Sudan, Yemen and Iran in 2007. Yellow or stripe rust has been in the region for many years but was contained by using certain resistant crops. Last year, however, a new, virulent strain emerged.

“Farmers lost up to 40 percent of their production through this heavy infestation. It was actually an epidemic last year,” he said, “which affected food security.”


An ongoing drought contributed to the problem. “This is one of the implications of climate change in this part of the world. Last year, the average temperature in winter was about four to five degrees higher than normal. So, apparently, the high temperature did contribute to new mutants that were there in the strain,” said Solh.

Farmers inadvertently helped bring about the mutation by using sprinklers to water their crops to ward off the effects of the drought.

“The sprinkler irrigation created the right environment with the high temperature for this disease to spread widely in a very short period of time,” he said. What’s more, wind can carry rust spores hundreds of thousands of kilometers.

What to do?

Scientists and other experts meeting in Syria agreed on the Aleppo Declaration, which offered recommendations for fighting the disease.

“The first one,” said Solh, “was certainly to pledge more support for strengthening the Global Rust Reference Laboratory in Denmark and upgrade the skills and facilities of the national and regional rust laboratories.”

Another recommendation was to replace varieties of wheat prone to yellow rust with new, resistant crops.

“We have resistant varieties and already three are now released. All we need at this stage is a quick seed multiplication,” he said. Also, fungicides are being used in the short term.

It’ll take time, however, to replace the crops threatened or already affected by rust.

Solh said, “We need at least two to three years of very hard work to replace at least more than 50 to 60 percent of what we have. After the two or three years, then I think we will have the opportunity to go on a much larger scale. So, you are talking about four to five years where you can really have full coverage.”

ICARDA is one of 15 centers supported by CGIAR, the Consultative Group on International Agricultural Research, based in Aleppo.