Ash dieback: Hopes of breakthrough with new fungicide Scientists are testing a new fungicide which could provide a breakthrough by slowing the spread of ash dieback. The disease, which was identified in the wild in Norfolk in October 2012, has killed thousands of ash trees across the eastern region. It is thought the fungus was originally blown across the North Sea from the continent. Forests in Norfolk, Suffolk, Kent and Essex were among the worst affected, and the disease has now spread to woodland and nurseries across the UK, according to the Forestry Commission. Scientists at the Sainsbury Laboratory near Norwich have teamed up with the University of Sussex to trial a fungicide which could suppress an enzyme produced by the ash dieback fungus.