Potato Virus Y

Potato Virus Y (PVY) is a plant pathogenic virus of the family Potyviridae and is among the most important plant viruses that affect commercial potato production.

Symptoms of Potato Virus Y

Depending on the particular strain, potato plants infected with PVY can develop a variety of symptoms ranging from a loss in yields, to the severe Potato Tuber Necrotic Ringspot Disease (PTNRD).

Key signs to look out for include:

  • Mosaic (as a Mosaic virus)
  • Mottling
  • Rapid death of the infected area
  • Brittle or distorted leaves (wrinkled or rough appearance)

Common Causes and Conditions of Potato Virus Y

Potato Virus Y is transmistted potato plants through grafting, plant sap inoculation and through aphid transmission, but may also remain dormant in seed potatoes.  A progressive increase in viral load and subsequent loss of crop can occur when using the same line of potato for production of seed potatoes for several consecutive generations.

Tubers infected with potato virus Y develop necrotic ringspots which renders them unmarketable, therefore resulting in a significant loss of potential resale value.

Controlling and Preventing Potato Virus Y

PVY cannot be cured, so you should destroy any infected plants and tubers at the first sign of symptoms before leaves touch adjacent plants. Touching leaves is how the virus passes between plants.

Preventative measures to control PVY include:

  • Only purchase certified, virus free seed
  • Practise good aphid control
  • Disinfect all your equipment prior to making any contact with the seed
  • Avoid any unnecessary contact with the plants to avoid the spread of pathogens