University of Illinois Plant Clinic: February 2012

This blog is in response to all the questions that I have been receiving about a newly discovered disease in the US called Boxwood Blight (Cylindrocladium pseudonaviculatum). This disease has not been found in Illinois, but has been found in other locations in the US:

Date Confirmed in US Location___

10/26/2011 Surry County, North Carolina

10/26/2011                 Middlesex, Fairfield, Hartford,
                                    New London Counties,
                                    Connecticut

11/01/2011 Carroll County, Virginia

12/13/2011 Providence County, Rhode Island

12/14/2011 Prince Georges County, Maryland

12/19/2011 Barnstable County, Massachusetts

12/20/2011 Washington County, Oregon

12/23/2011 Westchester County, New York

1/24/2012 Lancaster County, Pennsylvania
3/26/2012 Lake County, Ohio

Detection: http://www.nh.gov/agric/divisions/plant_industry/boxwood-blight.htm

Survey Status of Boxwood Blight; Leaf and Stem Blight

http://pest.ceris.purdue.edu/map.php?code=FBBJCXR

Boxwood Blight (Cylindrocladium pseudonaviculatum)

History:

•This disease was 1st described in UK –mid 1990’s

•2002 found in New Zealand and disease was named in UK

•Since 2002, this disease was reported throughout Europe

Host: Buxus species

1). Initial Symptoms dark to light brown spots/lesions on leaves. Leaves turn brown/straw colored and defoliation occurs quickly

2). Also infects stems with distinctive dark brown to black lesions (leads to plant death)

3.) Does not appear to affect roots

CONSIDERED A SERIOUS DISEASE

Key: DETECTION and DESTROY
Fungicides do not appear promising, but research is ongoing

If you suspect this disease on boxwood, please send a sample to a NPDN Plant Diagnostic Lab near you.