Wheat dwarf virus widespread in the UK, survey finds

Transmitted by the leafhopper Psammotettix alienus, wheat dwarf virus has long been recognised as a damaging cereal disease in continental Europe, but it has received little attention in the UK. 

Its symptoms can be easily confused with barley yellow dwarf virus (BYDV), meaning it has likely been overlooked or misdiagnosed.

Multiple sites confirmed 

But a collaboration of AICC members, entomologists and plant virologists has now confirmed WDV incidence at multiple sites in 2025 through targeted sampling and laboratory testing. 

Positive results have largely been seen in winter barley, but significantly, the disease has also been uncovered in recent winter wheat samples from Norfolk.

The emerging picture was revealed and discussed at a recent AICC technical meeting, chaired by Chris Nottingham of Apex Agronomy.

Tim Martin, also of Apex Agronomy, and entomologist Alan Dewar shared field observations and survey results from East Anglia and the international context of vector biology and disease behaviour.

Early detection 

Tim said it is a shining example of what the AICC’s network can deliver for the industry.

“Independent agronomists are walking crops across large areas every week. That puts us in a strong position to detect emerging issues early and, by working with researchers, turn those observations into robust, practical evidence.”

Initial results indicate that WDV is spread by primary infection in early autumn, rather than secondary spread within crops, aligning with the life cycle of the leafhopper vector. 

Patterns observed so far point towards greater risk in early-drilled crops, particularly on lighter soils following hot and dry summers that favour vector activity. 

Grasses, volunteers and cover crops may also act as reservoirs for the virus. 

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Understanding risk 

Importantly, the collaboration is focused on understanding risk rather than generating alarm.

“We are not saying this is a problem everywhere, but without recognising what we are seeing in the field, the industry cannot assess where the risks lie, or where research should be focused,” explained Tim.

Researchers involved in the work have highlighted significant gaps in current knowledge, including the national distribution of WDV, the strains present in UK cereals, and the effectiveness of cultural and varietal mitigation measures under UK conditions.

AICC members are now being encouraged to report suspected cases and submit samples to extend the survey beyond East Anglia. 

Findings will be shared with AHDB and DEFRA to support evidence-based decisions on future research priorities and management.

Survey findings to date

• Wheat dwarf virus confirmed at multiple sites in eastern England
• Infection detected in both winter barley and winter wheat
• Symptoms easily confused with BYDV, suggesting historical under-reporting
• Primary infection in early autumn rather than secondary within-crop spread
• Early drilling, hot dry seasons, light soils and grass reservoirs increase risk.

What is wheat dwarf virus?

• WDV is a viral disease affecting cereals, including wheat and barley
• It is spread by a leafhopper, Psammotettix alienus, not by aphids
• It causes stunting, yellowing of barley, reddening of wheat, poor rooting and plant death
• Infected plants are often scattered through crops in a “salt and pepper” pattern, rather than more distinct patches associated with barley yellow dwarf virus (BYDV)
• Infection typically occurs in early autumn, shortly after crop emergence
• Once infected, plants do not recover, and damage is permanent
• Yield losses range from negligible to severe, with published estimates in literature ranging from 20% to 100%, depending on infection level and crop compensation
• The virus can survive in grass weeds, volunteers and cover crops between seasons
• Hot, dry summers and autumns that favour the leafhopper vector increase risk
• There are currently no targeted chemical controls, so management will rely on improved awareness, cultural controls and longer-term varietal solutions.

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