Assessment of Specialty Potatoes for Powdery Scab Resistance

Experiments were conducted to assess potential genetic resistance to powdery scab in specialty selections currently under evaluation in the Oregon potato variety development program. Ratings varied widely among the varieties/selections, but none of the entries were completely free of root galls. The root gall ratings were not good predictors of tuber scab severity. Tuber scab incidence varied from 0 to 90 percent in the statewide specialty trial, from 0 to 100 percent in the PYT2 specialty trial, and from 0 to 80 percent in the PYT1 specialty trial. Several selections in each trial were significantly more resistant to powdery scab infection than the check varieties ‘Yukon Gold’, ‘Red LaSoda’, and ‘Dark Red Norland’.