Breeding Lines Show Promise Against Hessian Fly

MANHATTAN, Kan., Sept. 11--Two of the top Texas wheat breeding lines have resistance to the Hessian fly, U.S. Department of Agriculture scientists have found. One of the lines has two added bonuses: It's high-yielding and resists leaf rust, the major disease of wheat across the Great Plains' breadbasket.

The new-found resistance comes at a good time. After more than 200 years in the United States, the Hessian fly--notorious for damage to wheat in the central Plains states--was found this year for the first time in west-central Texas.

"If the breeding lines continue to show high yield potential and have other desirable traits, it may mean that new resistant varieties could be available to Texas wheat growers within five years," said Jimmy H. Hatchett, an entomologist with USDA's Agricultural Research Service here.

Until then, he said, some growers may want to consider available varieties such as 2180, 2163, 2165, 2157, and Pecos. Hatchett found them to be resistant to the fly in west-central Texas, as well as in Kansas. "Using these varieties in the outbreak area should reduce infestations," he said. "But farmers need to weigh their other characteristics such as disease resistance and yield ability.

"Part of the problem is that many west-central Texas growers plant their wheat early in the fall to establish good stands for livestock grazing during the winter," Hatchett continued. "This practice provides a near year-round smorgasbord for Hessian flies."

From Hatchett's base in the Plant Science and Entomology Research Unit at Kansas State University, he has tracked the Hessian fly in the U.S. for more than 30 years. As leader of ARS' Hessian fly project, he has collaborated with wheat breeders in Kansas, Nebraska and South Dakota in developing varieties resistant to the insect.

Until now, Texas wheat breeders didn't need to select wheat lines resistant to the Hessian fly because it wasn't considered a serious threat to Texas wheat production. Hatchett believes the fly has been in west-central Texas for some time and populations have just now reached outbreak levels.

A Texas A&M Agricultural Extension Service agent estimates the Hessian fly in McCulloch County alone caused some damage to 95 percent of its 48,000 wheat acres. For wheat producers in this county, the economic impact of the fly resulted in a $2.45 million loss in grain yields.

Chemical treatment for Hessian fly is expensive. Over the years, the main defense against this wheat-hungry pest has been the development and use of resistant wheat varieties. Until new, improved resistant varieties for the region are developed, Texas wheat- livestock producers are advised to make a few changes: plant wheat later in the season, rotate wheat with another crop and control volunteer wheat (plants that sprout up on their own).

Meanwhile, researchers are identifying new resistance genes that can be used in Texas wheat breeding programs. Their goal is to build an arsenal of resistant varieties for Texas producers to use in the future, wherever the Hessian fly decides to show up next.

Scientific contact: J. H. Hatchett, ARS-USDA, Plant Science and Entomology Research Unit, Kansas State University, Waters Hall, Manhattan, KS, 66506; phone: (785) 532-4719, fax (785) 532-6232, jhatchet@oznet.ksu.edu.