PVY, Potato Common Mosaic (Potato Virus Y)
PVY is the common strain of the PVY complex and is the most important virus infecting potatoes in Ontario. PVY persists in infected seed potatoes, volunteer potato plants and some weed hosts.
Other crops attacked by this virus are tobacco, tomatoes and peppers. Nightshade and groundcherry are the most important weed hosts.
The virus is transmitted by aphids in a non-persistent manner. The green peach aphid is an efficient vector of PVY. Some mechanical transmission of PVY can
also occur.
Symptoms. Symptom expression depends on the potato variety and the virus strain.
Shepody is very susceptible to PVY, although the symptoms may disappear in a few days. In Russet Norkotah the symptoms are not noticeable.
yellow, and dead leaves cling to the stem. This
symptom is called “leaf drop.” PVY-infected
plants usually die early.
spots. The necrosis is considered to be a plant
reaction to the virus infection.
Mottles are variable in size and are not delineated by leaf veins.
fewer and smaller tubers than healthy plants
(right).
The leaf on the left is healthy.
This symptom is called “vein banding.”
