Inspection of Scottish seed potato crops over the past few years have revealed an increasing incidence of both PVY and PLRV - the two predominant aphid-borne viruses affecting potato crops in Scotland.
Whilst Scottish seed potato health remains high and aphid-driven vector pressure remains relatively low when compared to other regions, a series of warmer winters has led to earlier and more abundant aphid numbers than usual which may have contributed to this increase in virus level.
Once again, average temperatures over winter 2024-25 have been warmer than average indicating that the first flights of M. persicae should be 2-3 weeks earlier than on average. Consequently, population levels have the potential to develop to levels that could threaten the virus health of seed crops.
Going into the 2025 season, virus inoculum levels for both PVY and PLRV are higher than usual, so effective management of the source of inoculum should be a priority. Best practice aphid control for the management of PLRV and PVY can differ, and it will be important to consider both in 2025.
A balanced approach to the management of both leaf roll and non-persistent viruses and their vectors with increased vigilance of the timing and number of aphids in your area is recommended for the 2025 summer.
Key Points
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Virus inoculum levels (both PLRV and PVY) were higher than usual in 2024
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Aphids are expected 2-3 weeks earlier than average
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Active virus management (for both PLRV and PVY) advised for 2025
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Increased aphid vigilance using traps and visual inspection of crops recommended
SASA