The City of Fredericton, New Brunswick (Canada) announced plans for an inoculation pilot project to slow the spread of Dutch elm disease (DED) in city-owned trees in May 2018. 

All elm trees with a diameter greater than 30 cm and located within pre-determined trial areas of Devon, and the downtown east and west part, as well as several larger elms of significance located in parks on the north and south side of Fredericton, were inoculated with DutchTrig®, a bio-control vaccine for elms.

Injected elms survive
The infection and survival rates of the inoculated trees were compared to non-treated elms in other areas of the city throughout the summer. Results were recorded for analysis in July 2018, during the City’s annual Dutch elm disease survey. The pilot was very successful and none of the elm trees in the pilot succumbed to DED. The pilot, also being cost efficient, will now be expanded to all elm trees in the City of Fredericton.

Simple treatment
In order to inoculate the tree, arborists will apply the vaccine by micro-injecting a small amount of DutchTrig® into the elms this spring, when the trees are at 25% or more in leaf development. The treatment is non-invasive, requires no drilling, and is completely safe for people, animals and the surrounding environment as it uses only plant-based pathogens associated with Dutch elm disease itself.

Trees for generations
Municipalities using DutchTrig® have experienced a dramatic increase in survival rate, with some communities showing 99% of injected elms being successfully protected against Dutch elm disease. A successful vaccination program will preserve the number of elm trees in the city and reduce removal and replanting costs, leading to a more efficient and self-sustaining urban forestry program for cities.