The Association of Independent Crop Consultants (AICC) has released the results of a new survey, suggesting that outbreaks of wheat dwarf virus (WDV) may be more widespread than previously thought.
Transmitted by the leafhopper Psammotettix alienu, the virus has been known on the continent but has previously received little attention in the UK. Symptoms can be confused for barley yellow dwarf virus, suggesting that it may have been previously misdiagnosed.
Working with entomologists and plant virologists, AICC members undertook targeted sampling and laboratory testing and confirmed multiple incidences. Positive results were largely seen in winter barley, however it was also found in winter wheat samples from Norfolk.
The results were 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.
Initial results indicate that WDV is spread by primary infection in early autumn, rather than secondary spread within crops. It was observed that early-drilled crops are at greater risk, especially on lighter soils following hot and dry summers.
Grasses, volunteers and cover crops may also act as reservoirs for the virus.
“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.
Those involved in the work have noted gaps in the current knowledge, including the distribution of the virus across the UK, strains present and the effectiveness of cultural and varietal mitigation measures.
AICC members are encouraged to report suspected cases and submit samples to extend the research beyond East Anglia. Findings will be shared with both the AHDB and Defra to support decision-making on future research priorities.