Effect of Potato Virus Y on Yield of a Clonal Selection of Russet Norkotah

Successful selections of Russet Norkotah lines have produced larger, more vigorous vines and higher yields than the standard Russet Norkotah (RN). Potato Virus Y (PVY), while producing mild or “latent” symptoms in this cultivar, has been shown to significantly reduce yields. To determine PVY’s effect on yield of a RN selection, PVY infected RN and Russet Norkotah selection 3 (RN3) yields were compared after planting in Hermiston, Oregon in 2001, 2003, and 2006. After emergence, individual plants were ELISA tested for PVY multiple times during the growing season to confirm infection. Plants were categorized when infected; 1) current season, 2) seed borne or 3) “no PVY”. At harvest, total and marketable yield data were collected. RN3 produced higher total yields than RN, regardless of infection categories. Highest yield reductions of RN and RN3 due to PVY were in the following order; seed borne PVY >>current season PVY >>no PVY.