Question to the Department for Environment, Food and Rural Affairs:

To ask His Majesty's Government whether they have made an assessment of the efficacy of sanitary felling in slowing the spread of Dutch elm disease.

Dutch Elm Disease is a highly destructive vascular wilt disease of several species of elm. We do not take statutory action against Dutch Elm Disease as it is widespread across most of Great Britain. There is no effective cure available for Dutch Elm Disease, but early sanitation felling, or removal of infected trees and branches, can slow the spread of the disease.

There is evidence that sanitation felling was used as a control method in the 1970s in specific areas such as Brighton and Hove which now houses the National Elm Collection, a well curated collection of hundreds of trees, containing cultivars of both susceptible and resistant species. Annual losses during this decade were variable but overall considered to be lower than areas where measures such as sanitation felling were not in place.

No official and specific assessment has been made on efficacy as local authorities make their own decisions on implementing control measures. However, local authorities such as Brighton with significant healthy elm populations that may still be implementing these enhanced control methods could hold more information on the use of sanitation felling at a local level.

Defra is currently prioritising investment in scientific research which aims to develop a more resistant and diverse elm population, to support the return of mature elms to the landscape nationwide. This includes mapping and gathering data on resistant elms across Great Britain, surveying their genomic diversity, evaluating the durability of disease resistant cultivars and establishing the current distribution of the two vector beetle species. Defra is also funding work with the John Innes Centre who are undertaking inoculation trials and propagating the most tolerant trees to establish new seed orchards with enhanced resistance to Dutch Elm Disease.