What is PVY?
- PVY is a serious, yield-limiting viral disease of potato found worldwide
- PVY primarily infects plant species in the family Solanaceae (pepper, tomato, tobacco, eggplant, potato, petunia, nightshades)
- PVY is spread by infected tubers and sap as well as many species of aphids including those that do not feed long term or colonize potato
- Infected seed potatoes are the most important source of PVY inoculum in potato fields
- PVY is an evolving cluster of genetically related virus strains
- PVY symptoms vary with strain of the virus, cultivar and environmental conditions
- Some emerging strains of PVY can cause tuber necrosis in some cultivars and most emerging strains cause mild foliar symptoms in most cultivars
- PVY has re-emerged over the last decade as a serious threat to potato production.
- Effective management of PVY is requiring changes to seed certification procedures and grower practices
What can I do about it?
Most PVY incidence can be traced to planting infected seed pieces, overwintering infected volunteer potatoes, or by planting near to infected fields. For more information see: Potato Virus Y Management.
Avoid introduction of PVY onto your farm.
- Don’t plant the problem!! Purchase the best certified seed potatoes.
- Select seed based on post-harvest test (PHT) estimates of virus incidence rather than estimates from summer inspections.
- Obtain PHT estimates based on lab testing vs visual assessment.
- Find out how many tubers were observed or tested for PVY to generate the PHT estimate.
- Don’t plant symptomatic seed. Inspect seed before planting.
- Avoid compost from contaminated sources outside your farm. Ensure these materials do not originate from potato debris or cull piles.
Manage the inoculum level in the field.
- Practice a strict on-farm sanitation protocol.
- Destroy overwintering sources of PVY.
- Rogue volunteer potatoes early in the season.
- Rogue infected plants throughout the season.
- Eliminate alternate weed hosts.
- Do not plant seed potato fields near fields of other Solanaceous crops.
Reduce spread of PVY by aphids.
- Isolate seed fields from commercial production.
- Use border crops to surround small, high-valued seed lots.
- Time planting and top kill to avoid aphid flights.
- Minimize colonizing aphid populations when scouting indicates aphid populations are above threshold levels.
- Spraying for immigrating winged aphids (colonizing or non-colonizing) is NOT effective in controlling the spread of PVY into a field.
- Anti-feedant compounds may help control spread of PVY by colonizing aphids.
- Mineral oils may reduce the spread of PVY by interfering with aphids’ interest and ability to puncture the leaf surface but do not protect the underside of the leaf and need to be sprayed often.
Understand the different types of resistance to PVY.
- Use immune cultivars whenever possible.
- Avoid planting tolerant cultivars in close proximity to fields with susceptible cultivars.