Following a decade of work, scientists at Washington State University transferred a gene from split peas to potatoes that improves the potato's resistance to a fungal disease called Verticillium wilt.
"The addition of the resistance capability to the Russet Burbank variety, which accounts for 70 percent of Washington's potato production, will make a significant contribution through reduction in nitrogen fertilizer and pesticide use and increased yields to our nearly $300 million potato industry," said university extension horticulturist Robert Thornton.
Washington potato growers spend about $23 million annually to fumigate their fields to control Verticillium wilt, nematodes and other pests.
Verticillium wilt, a soil-borne disease caused by a fungus, is found in most temperate regions of the world. In the Pacific Northwest, it affects crops ranging from eggplants to potatoes and ornamentals such as roses.
The disease clogs the vascular systems of host plants, blocking movement of water. Affected plants eventually turn yellow and die prematurely. In potatoes, the state's fifth-leading crop, the wilt hits as tubers are still developing, stopping growth and reducing yields.
A team of scientists led by Lee Hadwiger, a plant pathologist, transferred pea gene 49 to the Shepody and Russet Burbank potato varieties. This gene provides improved resistance to Verticillium wilt.
Under field conditions, the gene adds two more weeks of life to potato plants before they succumb to the disease. "Any time that you can add to the life of the potato after tubers start to develop, you can potentially increase yield," Hadwiger said.
In field tests last year, Shepody potatoes with the resistance gene produced up to twice the yield of unprotected potatoes exposed to the fungus.
Shepody is an early-maturing variety used to make French fries. It's harvested from mid-July through August, and accounts for about 10 percent of the state's potato tonnage.
Hadwiger has transferred pea gene 49 to the Russet Burbank as well, but that research is still early in development, and there is no field trial data available.
A tri-state variety testing program should begin as soon as enough seed potatoes have been raised. If the variety meets expectations, it could be available to growers in three to six years.
-- Nancy Garcia Associate Editor
(c) 1997 American Health Consultants. All rights reserved.