Effects of pruning in the management of dogwood and pine branch dieback in the landscape.

摘要

Sphaeropsis tip blight (caused by Diplodia sp.) of Scots pine (Pinus sylvestris), and branch dieback associated with dogwood (Cornus florida) anthracnose (Discula destructiva) and Botryosphaeria sp. canker are among the most prevalent and destructive diseases affecting the health and aesthetic qualities of these two important landscape trees in the NE United States. Scots pine trees at 2 locations and dogwood at 1 location (all in Pennsylvania, USA) were observed for branch dieback from spring 1996through until autumn 1998. Some trees at each location were comprehensively pruned to eliminate dead twigs and branches and were compared with trees which were not pruned. Of the branch-killing fungi present, Diplodia was the most important in the Scotspine trees, and Discula destructiva and Botryosphaeria sp. were the prominent ones identified in dogwood. It is concluded that although comprehensive pruning of branches killed by fungal diseases significantly improves the appearance of affected trees,it does not totally eliminate disease from the trees.