Potato Grower

WWW.POTATOGROWER.COM 31 THE BEST PRODUCTS • THE BEST SERVICE • THE BEST PRICE Celebrating 35 Years! SINCE 1982 GEAR BOXES • FAFNIR BEARINGS • ROLLERS HYDRAULICS • BELTED CHAIN BELTING • SPROCKETS A U T H O R I Z E D D E A L E R F O R ® Liquid Handling Products SUPERIOR CHAIN, INC. Minnesota Beltway USA 208-356-4317 1217 S. RAILROAD AVE • SUGAR CITY, ID 83448 TILLAGE • ELECTRIC MOTORS Your New Newhouse Dealer Your New Newhouse Dealer 164106MauWel12v.indd 1 12/20/16 3:26 PM Dr. Miller's advanced lines that had good resistance, but finding anything with strong resistance, even in the wildest germplasm, bodes well for availability of resistant varieties in the future." Novy sent seed tubers from 10 germplasm lines to the team in Amarillo; Miller's program sent seven. "We planted them in tents at the research farm near Bushland, with four plants per tent, and replicated each tent twice under center pivot," says Workneh. "Positive- testing psyllids raised in the greenhouse were placed in the tents—six per plant— after flowering." He says the psyllids were left on the plants for a week before an insecticide was applied. "Normally after potatoes are infected, symptoms will show within a month," says Workneh. "However, under this study, the potatoes were left for about 50 days to ensure anything infected would be exhibiting symptoms." The potatoes were dug up, sliced and rated visually for tuber symptoms on a scale from 0 to 3, with 0 meaning no infection and 3 being the worst. After they were rated visually, the slices were molecularly tested for titer levels—how much bacteria concentration the potato contained. "The severely infected potatoes will actually go down in titer level after a period of time, but only because they degrade rapidly if they initially had high titers," says Workneh. The results have all been gathered, and Workneh says the study resulted in some promising germplasm in the battle against zebra chip, especially three or four lines from the Texas A&M program and one or two from the USDA. All these will need to be further field-tested to verify the 2016 results. Workneh says the results will now be passed back to the breeders for further inclusion in their breeding programs. "Although the process seems painstakingly slow at times, it is necessary to provide the public with the high-quality produce they demand and to which they have become accustomed in the U.S.," says Rush. Potato psyllids cover the leaf of a potato plant. (Texas A&M AgriLife photo by Kay Ledbetter)

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