The wheat varieties may have lost some resistance but the fungus has returned with vengeance, more potent than it has ever been. Called Ug99, following its discovery in Uganda in 1999,this fungus is dangerous enough to defeat the resistance of most existing wheat varieties. No wonder, for the eight years since it was first noticed there hasn’t been any resistant variety of wheat in sight yet. The signs areominous.
Wheat crops in Uganda, Kenya and Ethiopia have been at its mercy. The fungus has already reached Yemen andgoing by the past record, once it reaches that far, it is not too far from the sprawling wheat fields ofSouth Asia. The previous emergence of yellow rust, a less deadly cousin of stem rust, in the 1980s had followeda similar route to destroy wheat crops worth US$ one billion along its way through Egypt, Syria, Turkey, Iran, Iraq, Afghanistan, Pakistan and India.?
The fact that stem rust is the worst of the three rusts that afflict wheat plants compounds the crises. The fungus rusts the wheat stem much like a rusted iron rod, plugging its vascular systemso that carbohydrates can’t travel from the leaves to the grain. The result: some 40 per cent of grain yield is lost. The Food and Agriculture Organization of the United Nations (FAO) has estimated that some 65 million hectares of wheat crop could be at risk worldwide.?