Given the existence of global wheat shortages, the prospect that the Ug99 strain of wheat rust could wipe out the nation's wheat crop has sounded alarms.
This strain of wheat rust, the most virulent in 50 years, was first identified in Uganda in 1999 (hence the name Ug99) and has since spread through the wind to East Africa, the Indian subcontinent and as far as Iran. Ug99 has been shown to cause 100% yield loss in infected plants. The Bill and Melinda Gates Foundation recently designated $27 million to fight the disease and prevent its devastating the world food supply.
Here in the U.S., the government recently issued an action plan to help coordinate efforts to minimize the effects of Ug99 on U.S. crops, including wheat and barley.
"This is an interesting pathogen and doesn't really fit a quarantine situation," explains Marty Draper, plant pathologist and USDA national program leader.
"Everything we will do once it gets here is similar to what we did with soybean rust."
USDA's action plan provides both a structured program and a scientific focus to ensure that the wheat and barley research, Extension and outreach communities achieve planned results in an effective and timely manner to minimize the impact of new races of stem rust.
The plan consists of eight key components that need to be tackled, including:
- assessing the vulnerabil-ity of current varieties;
- detecting the presence of Ug99 on U.S. shores;
- developing and implementing resistant germplasm;
- managing the disease with fungicides;
- coordinating international efforts to fight Ug99; and
- effectively communicating with all constituencies.
Developing resistance. A large but still unknown portion of wheat varieties around the world are highly vulnerable to Ug99, including an estimated 80% of wheat varieties in Africa and Asia, nearly all spring wheat varieties planted in the U.S. and 75% of winter wheat varieties planted in the U.S.
With such an impact in mind, University of Minnesota researchers have developed a hard red spring wheat variety that has shown moderate resistance to Ug99. The new wheat variety, named Tom, has been tested in wheat-growing areas throughout Kenya and has moderate resistance to scab. In addition, Tom is resistant to preharvest sprouting and stem rust and is moderately resistant to common varieties of leaf rust and other leaf diseases.
The university is planning to conduct on-farm trials in northwest Minnesota this summer. The release of Tom follows in the footprints of Ada and RB07, in which all releases were funded through the checkoff organization of Minnesota producers.
You can download the full USDA action plan against wheat rust strain Ug99 by going to www.ars.usda.gov/ug99/actionplan.pdf.
You can e-mail Jeanne Bernick at firstname.lastname@example.org.
- March 2009