ABSTRACT
Potato virus Y (PVY) is one of the most important of the potato viruses, but little is known about the impact on yield of seedborne infection levels below 100%. Blending infected and healthy seed from different seed lots introduces the variable of performance differences between the seed lots, which may obscure the effect of virus alone. Seed lots containing various levels of seedborne PVY (0, 2, 10, 20, and 50% incidence of infected tubers) were created by combining in different proportions seed pieces from healthy and infected tubers from the same seed source. These seed lots were planted in replicated field plots at the University of Idaho Parma R & E Center in Parma, ID from 1995 to 1997. Regression analyses on data from the three consecutive seasons indicate that seedborne PVY has virtually the same negative impact on yield for all three cultivars.
