Title: Sirococcus tsugae Tip Blight on Eastern Hemlocks - Pest Alert
Author: Miller-Weeks, Margaret ; Ostrofsky , William D.
Publication: USDA Forest Service, Northeastern Area, State & Private Forestry, 11 Campus Boulevard, Suite 200 Newtown Square, PA 19073
Abstract: Since 2006, observers have noted a tip blight of eastern hemlocks across a wide area in central and southern Maine that includes Androscoggin, Cumberland, Kennebec, Knox, Lincoln, Oxford, Sagadahoc, and York counties. The disease is especially apparent in natural stands on advance regeneration of hemlocks in the understory. In some cases it affects many shoot tips on a single tree. The tip blight infects the distal tips of branches, seldom killing more than one-half inch of shoot tip growth.
The causal pathogen has been identified as Sirococcus tsugae based on fruiting structures collected in fall 2009 and confirmed by the USDA Animal and Plant Health Inspection Service from morphological characteristics and genetic typing. This was the first report of S. tsugae occurring on eastern hemlock even though this pathogen is known to infect hemlock in the Western United States. It is not known how S. tsugae arrived in eastern forests.
Online Access: http://na.fs.fed.us/pubs/palerts/tip_blight/tip_blight_lo_res.pdf
High resolution document suitable for printing: http://na.fs.fed.us/pubs/palerts/tip_blight/tip_blight_hi_res.pdf
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