Foliar and Tuber Reactions of Three Strains of Potato virus Y on Five Fresh Market Potato Cultivars through Three Successive Potato Generations

Five fresh market potato cultivars commonly grown in western Washington were evaluated against Potato virus Y (PVY) O, NTN, and N-Wi using inoculated PVY-free plantlets in the greenhouse in 2015 and successive generations of seed tubers from foliar inoculated plants in 2016, 2017, and 2018. Mosaic displayed strongly on all cultivar by strain combinations, except All Blue by PVYO. Russet Burbank and Yukon Gold infected with PVYO had highest area under symptom progress curve values for leaf drop across all cultivars and years. Yields mostly were lowest for PVYO. More cracked tubers developed on G3 tubers in the field than greenhouse G2 or G1 plants. Chieftain infected with PVYO and PVYNTN, and Yukon Gold with PVYN-Wi had marked increases in tuber cracking by 2018. Cracking began at early plant growth stages; seed tuberborne rather than current season infections had higher cracking incidence; cracking became prevalent with succeeding seed tuber generations; cracking did not contribute to tuber weight loss during storage; and, PVY and tuber cracking substantially impacted yield.