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New Potato Variety Resists Blight

PULLMAN, Wash. — Agricultural scientists will soon release a new potato variety with the potential of increasing yields by 10 percent and reducing production costs by up to 30 percent.

The variety has increased resistance to late blight, the disease that caused the Irish Potato Famine, and which is increasingly attacking Washington potatoes.

Washington State University’s Debra Inglis, Mount Vernon, announced the variety’s approaching release at the annual statewide Potato Conference in Moses Lake, Wash., today (Wednesday, Feb. 5).

WSU’s Robert Thornton, extension horticulturist, said the variety is going through the final approval processes and could be available to growers by the 2004 or 2005 growing season.

The variety is the result of more than a decade of research by scientists in the Northwest Tri-State Potato Variety Development Program, Thornton said. A90586-11, the identification under which it has under gone development, is the result of an original cross made in 1990. The variety will receive a name before its release to farmers.

Inglis, a plant pathologist, said the new variety not only has improved late blight resistance and improved yield, it has good processing qualities and will allow farmers to reduce the number of fungicide applications by half.

Development of the new variety is good news for both traditional and organic producers, she said.

Over six years of testing at Mount Vernon, Inglis said scientists found about 50 percent less late blight on A90586-11 foliage at all levels of infestation.

Inglis said Mount Vernon’s mild marine climate was an ideal testing place because it favors the fungus that causes late blight disease.

Since A90586-11has been screened against most known race combinations of the fungus, scientists believe the new variety’s resistance is less likely to break down over time than current varieties.

“This one has stood out because of the consistency in its higher level of resistance,” Inglis said.

“One of the things we think is important is that the resistance doesn’t have to be perfect, the plant doesn’t have to be immune. Instead, we can use a line that has greatly improved resistance and cut the number of fungicide sprays by half.

Commercial growers usually make four to 10 fungicide applications a year, depending on conditions. In Inglis’ tests, fungicide applications were reduced from six a year to three.

“The entire industry wants to reduce fungicide use as much as possible, and this will reduce the number of applications, and the costs associated with fungicide applications.

A90586-11 is a cross between Ranger Russet, a currently popular variety developed under the same program, and Polish genetic material.

Development of A90586-11 was supported by a USDA special grant of $183,000 to Washington State University. The Washington State Potato Commission invested $59,000 annually in these trials and WSU conducted the trials in Washington.

A ten percent yield increase for Washington potato growers would be a $55 million increase over last year. An increase in processing quality and reduced losses of ten percent might benefit the potato french fry manufacturers another $6 million, and a reduction in fungicide costs could save possibly another $500,000 a year.

Potatoes are Washington’s third most valuable crop, after apples and milk.

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