A virus survey of New Zealand fresh process and seed potato crops during 201011

Abstract

A survey of 35 potato crops for potato viruses X Y S M A and leafroll was completed in three regions of New Zealand PVS was the most widespread virus with incidences of up to 100 in most crops PVM and PVA were present in around onethird of crops with PVM incidence at 100 in 11 crops The incidence of PVA was always below 35 PVY^N was present in 17 of crops Within crops PVY incidence reached 100 in two crops but in the remaining five crops was 50 or lower Potato leafroll virus was detected in only five crops at 2 or less and similarly PVX in three crops at 1 incidence Over 20 years PVS has increased in incidence whereas PVX PVY PVY^N and PLRV have decreased Of some concern is the apparent increase in the incidence of PVM Likely reasons for these changes in virus incidence are discussed along with future virus management recommendations