Folicur® protects against harvest losses caused by Ug99

Company conducts successful fungicide tests in Kenya

Black stem rust on wheat leaves caused by Puccinia graminis.
Monheim, May 2008 – A new, aggressive race of the black stem rust fungus (Puccinia graminis) is threatening global wheat stocks. Field trials conducted in Kenya by Bayer CropScience have successfully demonstrated that this race, designated Ug99, can be effectively controlled by the company’s established cereal fungicide Folicur® (active ingredient tebuconazole). Folicur® is already available to farmers in Kenya and Iran to combat stem rust. Bayer CropScience plans to register further fungicides based on Folicur® in these two countries to control the disease.

“This aggressive fungus is invading wheat fields around the world and spreading faster than agricultural scientists expected”, explains Dr. Frank Göhlich, Product Manager Fungicides at Bayer CropScience. “It threatens to cause devastating harvest losses in major wheat-growing countries in the coming years if measures to contain its spread fail.”

First appearance in East Africa

In 1999, African scientists made a discovery in Uganda that had serious consequences. Many wheat stocks were infested by a parasitic fungus which permanently weakened the plants, leading to a total loss of the harvest. The causative agent was a new, extremely aggressive variant of the black rust fungus (Puccinia graminis). Scientists named this new race of stem rust “Ug99” after the country and year in which it was first observed. “It can be recognized from the dark orange to dark brown lateral pustules it forms on the stalks and leaf sheaths of the plants”, says Dr. Stefan Dutzmann, Product Development Manager Cereal Fungicides at Bayer CropScience, describing the disease symptoms. Since then, the pathogen has continued to spread: it has been reported in Kenya, Ethiopia, Yemen and recently also in Iran. No end to its proliferation is in sight. Fears that fungal spores may already have reached Pakistan have not been confirmed to date. From here, it is not far to the fields of India, the world’s largest producer of wheat after Europe and China. This would lead to increasing shortages and further rises in the price of this important basic foodstuff. Experts estimate that potential annual losses could amount to more than EUR 2.2 billion.

In the long term, warmer regions such as Mexico and North America may also be at risk if fungal spores are introduced there, for example by travelers. The last large-scale outbreak of black stem rust in 1954 destroyed approximately 40 percent of the U.S. wheat harvest. It was not until many years later that resistant varieties of wheat were developed that cannot be harmed by black rust.

Food supply in emerging countries under threat

At present there are no varieties of wheat resistant to infection with Ug99, and many years could pass before new, resistant varieties have been bred and sufficient seed is available. Unfortunately, many farmers in emerging markets such as Pakistan and India cannot afford state-of-the-art crop protection products. “Thanks to Folicur®, we are now able to provide a cost-effective solution to effectively control black rust”, says Dr. Göhlich.

The food supply in emerging markets is strongly dependent on wheat growing. Ug99 is therefore a particular threat to these countries. In 2005, the Global Rust Initiative (GRI) was co-established by the Food and Agriculture Organization of the United Nations. The members of the initiative are working to jointly halt the spread of Ug99 and prevent any further proliferation. In addition to widespread surveillance and the targeted use of fungicides, their efforts are focused on searching for wheat varieties that are resistant to Ug99. However, the current findings are not very encouraging: 80 percent of the varieties tested to date are extremely susceptible.

Low risk for European agriculture

Although modern, intensive agriculture has become more susceptible to a number of fungal pathogens, this disease only presents a minor threat to European cereal fields. “Black rust is prevalent throughout the year in warmer climates, where the infection potential is permanently high. In the cooler, more moderate climate of Europe, this is not the case, however - stem rust cannot tolerate frost”, explains Dr. Dutzmann. In addition, the Pyrenees and the Alps function as natural barriers for fungal spores transported by the wind.

Bayer AG is a global enterprise with core competencies in the fields of health care, nutrition and high-tech materials. Bayer CropScience AG, a subsidiary of Bayer AG with annual sales of about EUR 5.8 billion (2007), is one of the world’s leading innovative crop science companies in the areas of crop protection, non-agricultural pest control, seeds and plant biotechnology. The company offers an outstanding range of products and extensive service backup for modern, sustainable agriculture and for non-agricultural applications. Bayer CropScience has a global workforce of about 17,800 and is represented in more than 120 countries. This and further news is available at: www.newsroom.bayercropscience.com.
Forward-Looking Statements
This release may contain forward-looking statements based on current assumptions and forecasts made by Bayer Group or subgroup management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Bayer’s public reports which are available on the Bayer website at www.bayer.com. The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.