Potato is the second most important food crop in the UK, and the underpinning seed potato industry contributes >£1 billion to Scotland’s economy. Aphid-vectored viruses threaten potato harvests because infected crops are downgraded or destroyed. Historically, Scotland has maintained low virus levels in potato crops, but this is changing due to the warming climate, new virus variants, loss of crop protection products, and aphid resistance to insecticides. New practices and efficient dissemination are needed urgently to protect the potato sector and prevent virus infections becoming more severe. Hutton researchers are working closely with industry to tackle this emerging issue.
Stage
Work in ProgressDirectory of Expertise
Purpose
Control of aphids on potato crops, and the economically damaging viruses they transmit, is an ongoing challenge in Scotland that has become more severe in recent years. Potato crops are attacked by several aphid species, most commonly by the peach-potato aphid (Myzus persicae) and the potato aphid (Macrosiphum euphorbiae). These aphids transmit disease-causing viruses such as Potato virus Y (PVY) and Potato leafroll virus (PLRV).
Historically, agronomic best practice, including effective insecticides, combined with high regulatory standards have ensured that virus levels remain low and that Scottish potato crops achieve high seed qualities, but these industry safeguards are now being challenged by the changing climate and other factors. The area of potato seed crops being downgraded in Scotland due to virus infection increased from 6% in 2022 to 15% in 2023. PLRV was responsible for more than half of these downgrades in 2023.
Effective virus control has been severely affected by loss of insecticides, development of aphid resistance to remaining insecticides, climate change favouring aphid winter survival and earlier spring flights, slow uptake of new resistant potato cultivars, a lack of clarity about alternative control strategies, potential change in pathogenicity and symptoms of new virus variants, and economic and geopolitical factors affecting food safety and supply. There is widespread acceptance that new sustainable and environmentally sensitive approaches – often referred to as Integrated Pest Management (IPM) - are needed to control aphid-transmitted viruses. Here, we report current progress in Scottish potato-aphid-virus research and outline where future effort and investment is needed.
Results
Our research tackles the five priorities outlined by the Scottish Aphid-Borne Virus consortium:
1. Understanding the biodiversity of aphid vector and virus populations. Our work reveals changes in vector and virus populations over several decades. This includes changes in the dominant aphid genotypes (the genetic makeup of an organism), with modern genotypes having multiple types of insecticide resistance, and a new PLRV variant replacing the historic variant, coinciding with increased virus incidence.
2. Impact of environmental drivers on vector and virus abundance. The predictive models we have developed reveal where virus pressure is likely to be high from one season to the next. Analysis of aphid suction trap data has identified meteorological and land use variables correlating with shifts in aphid species composition.
3. Scientifically validated Integrated Pest Management. Our field trials are investigating whether companion cropping and alternatives to insecticides reduce aphid infestation, and increase natural enemy activity, without promoting new types of aphid resistance. We are also investigating the mechanisms behind aphid/virus resistance detected in certain commercial and experimental potato cultivars.
4. Innovative Decision Support Tools. Using Artificial Intelligence (AI) to interrogate existing Scottish data, we have produced new, highly accurate warning systems for PVY and PLRV by forecasting local virus pressure for the following season at the end of the current season.
5. Socioeconomic acceptability and impacts of Integrated Pest Management. Collaborative scenario planning with industry stakeholders identified actions to strengthen the sector against pest and disease threats. These recommendations are being disseminated to growers, regulators, and policy, and guide our research to develop industry-acceptable methods for disease control.
Benefits
Our research ranges from informed disease resistance breeding, and fundamental understanding of aphid and virus population dynamics, to applied field testing of strategies to reduce the threat to Scottish potatoes from aphid-transmitted viruses.
New knowledge on virus and aphid diversity helps growers to use the limited available insecticide options more effectively and alerts the industry to new potential disease risks. Modelling of local virus pressure from the previous year allows ample time to adjust virus management programmes. These decision support tools become more powerful when combined with the latest agronomic advice on best practice for aphid and virus control.
Further development of validated Integrated Pest Management strategies involves bringing together crop resistance, insecticide alternatives, natural pest control, and accurate pest monitoring methods so that controls are applied only when needed. This goes hand-in-hand with a comprehensive assessment of the socioeconomic factors that prevent or enable changing practices.
Researchers, agronomists and regulators work closely to consult the sector, collect samples, and share results. Agronomists ensure the latest information reaches growers and industry stakeholders through workshops, conferences and extensive advisory networks. Disseminating the Scottish Aphid-Borne Virus consortium’s six steps to effective virus management in potato crops is essential for sharing efficient management practices and smoothing the strong regional variations in virus management.
The Scottish Aphid-Borne Virus consortium is committed to tackling the challenges posed to the potato sector by the changing climate, pest populations and socioeconomic conditions. To achieve this goal, further investment is crucial to address unanswered questions and apply research results on Scottish farms.
Lead image: Symptomatic PLRV-infected potato plants. Photo credit: Dr Eugene Ryabov.
Project Partners
The Scottish Aphid Borne Virus consortium comprises Hutton researchers and the following partners:
Christophe Lacomme (SASA) https://www.sasa.gov.uk/content/dr-christophe-lacomme
Fiona Highet (SASA) https://www.sasa.gov.uk/content/fiona-highet
Eric Anderson (Scottish Agronomy) https://scottishagronomy.co.uk/what-is-scottish-agronomy/meet-the-team/
Kyran Maloney, Gavin Prentice, Kerry Leslie (SAC Consulting) https://www.sruc.ac.uk/business-services/sac-consulting/our-expert-teams/
Andrew Christie
John Addy
Documents
- Farm Saved Seed – Virus Workshop
- Aphids: the secrets of their success
- Understanding the effects of virus genetics and potato variety on potato leafroll virus symptoms - Poster
- Understanding the genetic mechanisms of resistance to Potato leafroll virus in potato - poster
- The highs and lows of aphid control using alternatives to pesticides - presentation
Related Links
Research Papers
- Concepts of diversity – the key to effective IPM for climate resilience in arable systems?
- Landscape-scale patterns and predictors of potato viruses in Scotland.