Some of the most important challenges that face the seed potato industry are the potato viruses such as potato virus Y (PVY) and potato leaf roll virus (PLRV). Significant developments have taken place over the last several years in our understanding of the potato virus Y complex (PVY) which is now made up of not only the PVYo (ordinary strain), but also includes the PVYn (tobacco veinal necrosis strain) and the PVYntn (potato tuber necrotic strain) variants. In addition, more and more previously unreported viral strains, probably recombinants, with new and unknown capabilities continue to be discovered within U.S. seedstocks. The impact of PLRV (and the serious "net necrosis" tuber symptom that it causes) was greatly reduced by the advent of systemic insecticides, such as imidacloprid, that effectively control the aphid vectors of the virus.
While the amount of PLRV in Idaho seed lots has not rebounded to high levels, there appears to have been a small but steady increase over the last three years.