Abundance of weed hosts as potential sources of onion and potato viruses in western New York

A season-long survey of common weeds was taken near onion and potato fields located within a large vegetable production region in western New York in 2008 and 2009. The objective was to determine the abundance of weed species known as hosts for Iris yellow spot virus (IYSV), a serious pathogen of onion, Potato leafroll virus (PLRV) and Potato virus Y (PVY), which are major pathogens of potato. Ninety-eight weed species were identified, 17 of which are known hosts for IYSV, PLRV and PVY. Common lambsquarters, redroot pigweed, shepherd’s purse, horseweed and dandelion were among the most abundant species known as hosts for these viruses. This information could be useful for studying the role that these weed species have on the epidemiology of the major viruses in onion and potato production systems and for developing future virus management strategies.