The Hindu Business Line : Stem rust threatens wheat crop in India, Pak

Problem at hand
Disease is now infecting plant in Yemen and can propagate further to South Asia.
Evidence that it has spread into Sudan but tests needed to confirm it.

Thiruvananthapuram , Jan. 18

Wind models indicate that a new form of stem rust, a virulent wheat disease, now infecting wheat in Yemen in the Arabian Peninsula, could propagate itself to the east and threaten crops in Pakistan and India.

The Global Rust Initiative (GRI) and the Agricultural Research Service of the US Department of Agriculture (USDA-ARS) have confirmed conclusively the existence of the disease in Yemen.

Trajectory

There is also evidence that the disease has spread into Sudan but more tests are needed to confirm the finding. Until this discovery, this new strain of stem rust, known as Ug99, had only been seen in Uganda, Kenya and Ethiopia. It is capable of destroying most disease-resistant wheat varieties.

GREATER RISK

Sometime ago, geographic information system specialists plotted the probable trajectory of the fungus, whose spores can be carried long distances by the wind. The wind models predicted that if the fungus crossed from eastern Africa to the Arabian Peninsula, it could easily spread to the vast wheat-growing areas of North Africa, West Asia, Pakistan and India.

There is precedence for this from a virulent strain of another wheat disease, called yellow rust, which emerged in eastern Africa in the late 1980s. Once it appeared in Yemen, it took just four years to reach the fields of South Asia. On its way, this caused major wheat losses in Egypt, Syria, Turkey, Iran, Iraq, Afghanistan, and Pakistan, exceeding $1 billion in value. There is every reason to believe the new Ug99 strain of stem rust represents a much greater risk to the world wheat production. Annual losses of as much as $3 billion in Africa, the West Asia and South Asia alone are possible.

According to the Food and Agriculture Organisation, countries in the immediate pathway grow more than 65 million hectares of wheat, accounting for 25 per cent of the global wheat harvest.

If the rust threat is not controlled, it would have a major impact on food security, especially since global wheat stocks are at a historic low.