Aberdeen, Idaho, USA
May 25, 2012

University of Idaho researchers hope the new soft white spring wheat cultivar UI Stone will prove solid in its resistance to the fungal disease Fusarium head blight, an emerging threat to southern Idaho wheat and barley crops.

The first work that led to UI Stone by U-Idaho College of Agricultural and Life Sciences wheat breeders in 1994 focused on developing a new Pacific Northwest soft white spring wheat with superior yields and end use qualities.

Wheat breeder Jianli Chen, who is based at the college’s Aberdeen Research and Extension Center, screened potential new wheat varieties for resistance to the fungal disease using new molecular biology methods.

Next year the new variety will be available to wheat growers. The quality of flour from UI Stone exceeds or equals that from other varieties including Alturas, Alpowa and UI Pettit.

Fusarium head blight, also known as scab, can devastate wheat crops. A toxin produced by the fungus can make the grain unmarketable. Outbreaks in southern Idaho 30 years ago cost growers half their crops. Signs in 2009 and 2011 show that scab may again become an emerging threat, said Juliet Marshall, an Idaho Falls-based cereals pathologist.

An increase in the amount of corn grown in southern Idaho probably led to the recurrence of the disease, Marshall said. Growers can reduce the threat by separating the rotation of wheat and barley from corn crops in the same fields with others such as sugar beets.

UI Stone offers wheat growers three main advantages, Chen said:

• Good resistance to Fusarium head blight, the first U-Idaho cultivar released to growers with that benefit. UI Stone also shows moderate resistance to stripe rust, although variety trials showed variable results.
• Superior yields in both irrigated and non-irrigated fields. Average yields reached 120-plus bushels in southern Idaho’s irrigated fields. Average yields topped 60 bushels in non-irrigated fields in northern Idaho and adjacent Washington and Oregon..
• UI Stone also offers excellent end-use quality in cookies or noodles.

Although the first wheat cross that led to UI Stone was made in January 1994, extensive field evaluation began in 2005, mainly to test its resistance to stripe rust, stem rust and other fungal diseases.

Variety trials from 2008 to 2010 evaluated UI Stone at 11 sites in Idaho, Washington, Oregon and Montana. The new variety showed good resistance to Fusarium head blight in multi-state trials.

The push to find resistant varieties coincided with a growing incidence of Fusarium head blight in some parts of southern Idaho, Marshall said.

When the fungus Fusarium graminearum infects wheat or barley, it can produce a mycotoxin. At high enough concentrations, the toxin can make the grain unusable for human or animal food, leading grain buyers to reject it.

The fungus can survive in crop residues after the corn is harvested, particularly the hard corn crowns that resist breaking down for a year or more in southern Idaho fields. That’s why providing enough time in the crop rotation between wheat and barley crops and corn is so important, Marshall said.

Marshall said she saw only two or three instances of a total loss due to excess toxins last year when fields were infected with Fusarium head blight. Still, that was enough for wheat growers to recognize the threat and for Marshall and Chen to seek ways to combat the disease.

Chen and Marshall will each benefit from the two $1 million endowments created by the Idaho Wheat Commission earlier this year. The funding supports their work in breeding new varieties and finding ways to lessen crop losses from disease.
 

Website: http://www.uidaho.edu

Published: May 25, 2012