Potato Virus Y
Potato aphids are known vectors of PVY.
Necrotic lesions on potato tuber.
HOSTS
- Potato
BIOLOGY
Potato Virus Y is a Potyvirus spread by aphids and tuber seed species. There are three strains: PVYO, PVYN, and PVYNTN. It is a concern throughout the growing season.
- In Utah, infection most frequently occurs when infected seed pieces are introduced into a field. The disease is then spread within a field and beyond by aphids and farm equipment.
- Overwinters in infected seed pieces and in solanaceous weeds (e.g. nightshade, ground cherry).
SYMPTOMS
PVYO causes mosaic symptoms on the leaves and no symptoms on the tubers. PVYN causes necrotic spots on leaves and tubers. PVYNTN causes necrotic lesions on leaves and necrotic ringspots on the tuber surface that extend into the flesh. Infected plants are typically stunted.
GENERAL MANAGEMENT
PVY symptoms lead to yield reduction and loss of tuber quality. This disease is one of the most serious challenges facing seed potato producers.
- Watch for symptoms throughout the growing season.
- Monitor aphid activity throughout the growing season.
- Remove infected plants.
- Use certified seed potatoes that have been tested for PVY and have more than 90% guarantee to be disease free.
- Control weeds and alternative hosts.
Insecticide applications to control aphids are ineffective
Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.