SURVIVASH

Since 2008, ash trees are threatened in Switzerland by ash dieback (ADB), a fungal disease introduced from Asia to Europe. While more than 90% of the trees suffer from the disease, some few are almost symptom-free. A survey revealed 397 seemingly tolerant trees on 144 sites in Switzerland, north of the Alps. However, a new pest has the potential to kill the remaining ash trees: the emerald ash borer (EAB), an Asian wood boring beetle. Started in early 2019, the project aims to test the seemingly tolerant ash trees discovered in Swiss forests against EAB and new Asian strains of the ash dieback pathogen. For the project, 10 sites in Switzerland were selected. From each site, one tolerant and one ADB-susceptible ash tree were selected and grafted 50 times. All tests will be conducted under secured conditions in the new Plant Protection Lab @ WSL.