World’s wheat basket at risk

Ug99, named for its place and date of identification, has touched down in East Africa and the Near East, leaving behind fields filled with shriveled wheat grains. Major wheat rust epidemics have occurred in the past, namely in the 1950s and more recently in Ethiopia in 1993-94, with devastating consequences. An Ug99 outbreak could be even more disastrous. The UN Food and Agriculture Organization (FAO) estimates that 29 countries in East and North Africa, the Near East, Central and South Asia, accounting for 37 percent of global wheat production, are already affected by Ug99 or at potential risk. An estimated 80% of the wheat varieties currently being grown in this region are considered susceptible to Ug99.

Rapidly expanding threat

A large proportion of the commercial wheat varieties in the world are susceptible to Ug99 at a time when wheat stocks are historically low and wheat prices are historically high. In the 1950s, after devastating wheat stem rust epidemics in North America, scientists developed high-yielding wheat varieties that were resistant to stem rust and other diseases. Forty years without an outbreak led to an air of complacency, with governments dismantling training and surveillance programmes. Although Ug99 was first detected in 1998, and formally identified the following year, it was only in 2005 that the issue was brought to the world’s attention through the efforts of Nobel Laureate Dr. N.E. Borlaug – the wheat scientist who led the battle against stem rust in the 1950’s. Ug99 has subsequently moved into Yemen and Sudan (2006) and by 2007 it had reached Iran following regional winds. Further onward movement into the important wheat areas of Central and South Asia is considered likely. Of equal concern is that pathogen is changing, with at least two new variants now recognized – one of these causing epidemics in Kenya during 2007.

Working against the clock

Resistant varieties need to be developed and seeds multiplied and made available to farmers. Plant breeders around the world are working against the clock, considerable progress has already been made and the first Ug99 resistant varieties released. But this is more than a job for researchers. This is a global problem that needs global attention. Ug99 spores do not stop at national borders. Potential impact varies from country to country. Long-term effective disease control will depend on the use of durable resistant varieties. Applying fungicides is not economically feasible in most countries, especially in the developing world where wheat is a subsistence crop. Here crop losses affect farming communities and family food security immediately and profoundly. The entire world will be affected by the loss in wheat yields, either not finding enough to eat at the market or paying the increasing prices that will come from scarcity.