Three New Varieties Released From Aberdeen, ID

The Tri-State Potato Variety Development Program announced this week that it will release three new varieties, including one that can withstand late blight.

Named Defender, the late-maturing, unrusseted "long white" potato develops late blight symptoms so slowly that growers who would otherwise be spraying fungicides weekly need not spray for late blight at all.

Stephen Love, program coordinator and superintendent of the University of Idaho's Aberdeen Research and Extension Center, says Defender also outyields Russet Burbank under disease-free conditions by 10 percent or more.

At least 80 percent of its tubers rank U.S. No. 1 and their favorable solid matter content--a critical economic factor for french fry processors--exceeds that of Russet Burbank.

The Tri-State Program--comprised of potato breeders from the USDA/ARS, U of I, Oregon State University and Washington State University--is also releasing two other varieties this spring, including one that withstands drought.

Richard Novy, USDA/ARS breeder at Aberdeen, says Defender is the first North American potato whose foliage and tubers are both highly resistant to the aggressive forms of the late blight fungus that emerged as a problem for the regions growers in the early '90s. But he notes that Defender, once experimental cultivar A90586-11, is "not just an anomaly with late blight resistance--it has other qualities that interest the industry."
In additoin to high solids, Defender is also less susceptible to shatter bruise, corky ringspot and growth cracks than Russet Burbank and offers resistance to verticillium wilt and potao virus X

On the downside, it slighlty more susceptible to blackspot bruise, can only be stored for five-to-six months, and because it lacks the russeted skin that the Pacific Northwest's fresh pack market demands--will likely only be grown for processing into frozen potato products.

GemStar Russet, a variety that performs well despite water stres and that consistently produces large quanities of exceptioanlly well-shaped tubers, is the second of this spring's releases. According to Novy, it "tolerates reduced levels of moisture quite well: and still brings in a good crop.

"It produces high yields of a very high grade of poatoe with really nice appearance, and it cooks and eats well," agrees Love.

He expects GemStar Russet--origanally numbered as A9014-1--to begin replacing the quality-plagued Russet Norkotah in the market place. Unfortunately, GemStar Russet is unusually susceptible to both potato virus Y and hollow heart.

The third new variety, Western Russet, has been tested for the past eight years as A7961-1. An oblong russet with high yields and solids and a good proportion of large tubers, it outperformed all other potatoes in Western Regional trials for early harvest processing. In addition, it held up well in late harvested storages. Resistant to malformations and internal defects, it should be useful for both processing and fresh markets, Love says.