Erratum to: Influence of Location, Year, Potato Rotation, and Chemical Seed Treatment on Incidence and Severity of Silver Scurf on Progeny Tubers

A three-year study was conducted in 1999, 2001, and 2002 to examine the influence of seed-borne inoculum and fludioxonil+mancozeb seed treatment on silver scurf (caused by Helminthosporium solani) development on progeny tubers at six locations under different potato rotations in the semi-arid U.S. Pacific Northwest. Disease-free pre-nuclear seed and diseased generation 3 seed was either treated or not treated with fludioxonil plus mancozeb, planted, and progeny tubers were harvested and then evaluated for silver scurf incidence and severity. Experiments were conducted in the southern Columbia Basin (Oregon), northern Columbia Basin (Washington), central Oregon, southern Oregon, western Idaho, and eastern Idaho under short (<3 years), normal (3–5 years), and long (>5 years) potato rotations over the three years for a total of 19 location-year-rotation combinations. Significant differences were observed among years and locations with disease incidence being highest in central Oregon. Progeny tubers from untreated generation 3 seed had significantly higher silver scurf incidence (18.4 %) and severity (1.3) compared to untreated progeny tubers from pre-nuclear seed (1.2 % and 0.04 for incidence and severity, respectively). Seed treatment with fludioxonil+mancozeb reduced incidence (3.8 %) and severity (0.2) significantly compared to the untreated control (15.8 % and 1.1 for incidence and severity, respectively). Significant (P < 0.0001) interactions between treatments and location-year-rotation were observed and additive main effects multiplicative interaction analysis discriminated those with high incidence, severity, and variability. These data indicate that seed, not soil, is the primary source of progeny tuber infection in the field in the Pacific Northwest. For long term storage, purchase of clean seed is an essential component for managing silver scurf.