Submitted to: American Journal of Potato Research
Publication Type: Abstract only
Publication Acceptance Date: 3/19/2005
Publication Date: 1/1/2006
Citation: Whitworth, J.L., Hamm, P.B., Hane, D.C., Mcintosh, C.S. 2006. Effect of potato virus y (pvy) on yield of russet norkotah lines. American Journal of Potato Research. 83:138. Interpretive Summary: Selections from the standard Russet Norkotah cultivar were made in the early 1990’s. These selections tend to produce a more vigorous vine and have also been documented to produce higher yields than the standard cultivar. Russet Norkotah is very susceptible to Potato virus Y (PVY) and the selections from the standard also exhibit this trait. PVY infected plants have a reduced yield compared to healthy plants. Since the selections out yield the standard, this experiment’s objective was to determine if PVY infected Norkotah selection 3 (NK3) out yields a standard PVY infected Norkotah line. Results showed that NK3 out yielded standard Norkotah in all infection categories (no PVY, seed borne PVY, current season PVY). In addition, PVY percent yield reduction was greater for standard Norkotah in 2001 than for NK3.
Technical Abstract: Russet Norkotah is an early maturing fresh market variety released in 1987. It is now the second largest cultivar produced based on acres planted. In the early 1990’s several line selections were made in Colorado and Texas from giant hill plants. The successful selections produced higher yields than the standard and also had more vigorous vines and resistance to early dying caused by Verticilium wilt. The standard Norkotah is very susceptible to PVY and has reduced PVY-mosaic symptom expression that borders on latency. Even though symptom expression is reduced, the amount of yield reduction in Norkotah due to a percentage of PVY has been shown to be the same as for Shepody and Russet Burbank. This research examined yield components of standard Norkotah vs. Norkotah selection 3 (NK3) infected with PVY. Samples from seed lots that were over recertification tolerances for PVY were chosen and planted in a randomized complete block design in Hermiston, Oregon in 2001and 2003. Individual plants were ELISA tested for PVY early and late in the growing season to determine healthy, current season, and seed borne infection of each hill. After harvest, yields were graded and the data analyzed by regression. Results show that the NK3 selection produces higher total yields than standard Norkotah in all infection categories. In addition, yield of both Norkotah lines yield was reduced in the following order; healthy>>current season PVY>>seed borne PVY.