Fungus threatens to destroy wheat harvest


A fresh attack by the destructive fungus could deal a major blow to Kenya, which is a wheat deficit nation. Photo/JARED NYATAYA

Wheat farmers are staring at huge losses following the emergence of a destructive fungus that wiped out close to 80 per cent of the crop in Kenya in 2008.

In a development likely to trigger a fresh wheat price rally, scientists have found four new mutations of the Ug99 fungus in South Africa that are resistant to the existing genetic crop breeds specially developed to help fight the pathogen.

“With the new mutations we are seeing, countries cannot afford to wait until rust ‘bites’ them,” said Ravi Singh, a senior scientist in plant genetics and pathology with the Mexico-based International Maize and Wheat Improvement Centre (CIMMYT).

“The variant of Ug99 identified in Kenya, for example, went from first detection in trace amounts in one year to epidemic proportions the next year.”

In Kenya, the rust disease caused massive damages to wheat farms around Narok and Uasin Gishu districts nearly three years ago triggering massive climbs in consumer prices of wheat flour products such as bread after a 90kg bag of the commodity shot up from Sh1,800 to Sh3,000 at the peak of the attack.

Globally, projections by the Food and Agriculture Organisation (FAO) showed that as at January 2008, the global prices of wheat were 83 per cent compared to the same period of 2007.

The new races of fungus have acquired the ability to defeat two of the most important stem rust-resistant genes, which are widely used in most of the world’s wheat breeding programmes.

Scientists further estimate that 90 per cent of the wheat varieties around the world lack sufficient resistance to the original Ug99—meaning an attack by the new traits of fungus could lead to massive destruction.

“Already, most of the varieties planted in the wheat fields of the world are vulnerable to the original form of Ug99. We will now have to make sure that every new wheat variety we release has iron-clad resistance to both Ug99 and the new races,” Dr Singh said.

A fresh attack by the destructive fungus on world wheat plantations could deal a major blow to Kenya which is a wheat deficit nation producing just about a third of its annual demand of 900,000 tonnes.

The country relies on imports especially from Egypt and Mauritius under special arrangements with the Common Market for Eastern and Southern Africa (Comesa) to meet its deficit.

Egypt alone is entitled to bring in about 16,000 tonnes of the commodity into the local market each year while the latter brings in slightly above 1,000tonnes.

Though the Ug99 was initially found in Uganda in 1999, it soon found its way into Kenya and later spread into Ethiopia then to Yemen where it manifested even more virulent traits.

It was also later traced to regions as far as the middle-East.

“We do not have as much information as we would like on the aggressiveness of the pathogen,” David Hodson of the Food and Agriculture Organisation (FAO) said.

“The original race, Ug99, does not seem to have increased as much as originally feared, given its highly virulent nature. But the new variants pose a grave challenge that we are addressing in collaborations around the world.”

The scientists warned that if not checked through effective research, seed production, and distribution of resistant varieties, Ug99 may become another cause of food shortage.