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Research article - Peer-reviewed, 2017

Can pruning help maintain vitality of ash trees affected by ash dieback in urban landscapes?

Marciulyniene, Diana; Davydenko, Kateryna; Stenlid, Jan; Cleary, Michelle


Hymenoscyphus fraxineus causes a destructive invasive tree disease known as ash dieback threatening the survival of common ash not only in the forests, but also in urban and landscape settings. Pruning is a potential management practice that could help maintain tree vitality and aesthetics in parks, gardens, alleys and recreation areas, as well as maintaining veteran trees having high heritage or cultural value, or trees with high genetic importance (e.g. located in clonal seed orchards). In this study we investigated the maximum distance proximal to the lesion margin at which H. fraxineus can be detected on individual branches infected by the fungus in order to provide recommendations for pruning. Pruning of branches was carried out on 38 trees in southern Sweden. Tissue samples including bark and wood were collected from the margin of the lesion and at 5 cm intervals proximal to the lesion. Molecular analysis revealed presence of H. fraxineus in 91.3% of the investigated lesions. The proportion of lesions at which H. fraxineus could be detected declined with increasing distance from the lesion margin, with a significant reduction in the number of positive samples at 10 cm proximal to the margin. At 30 cm from the lesion edge the pathogen was never detected. Our results suggest that routine pruning may help maintain the vitality of younger trees. Pruning branches at least 35 cm from visible, active lesions in the bark should exclude the fungus and therefore reduce the probability of stem infection by H. fraxineus, however this cultural control tactic may only be economically feasible for high value amenity trees.


Fraxinus excelsior; Common ash; Ash dieback; Hymenoscyphus fraxineus; Pruning

Published in

Urban Forestry and Urban Greening
2017, Volume: 27, pages: 69-75

      SLU Authors

      • Davydenko, Kateryna

        • Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences
        • Kharkiv State Zooveterinary Academy
        • Stenlid, Jan

          • Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences
        • Associated SLU-program

          SLU Plant Protection Network

          Sustainable Development Goals

          SDG11 Sustainable cities and communities

          UKÄ Subject classification

          Forest Science

          Publication Identifiers


          Permanent link to this page (URI)