Natural Resources Conservation Service
P.O. Box 311
3381 Skyway Drive
Auburn, Alabama 36830
Date: February 8, 2006
ALABAMA BULLETIN AL190-6-8
Subject: ECS – Annosus Root Rot Hazard
Purpose. To transmit information on Annosus Root Rot (ARR).
Expiration Date. September 30, 2006.
During the Forest Health and Wildlife training on January 19, we discussed the disease
Annosus Root Rot (ARR). Enclosed is the ARR management information and hazard
rating list per soil series for Alabama.
We recommend this be included in all conservation plans where thinning is
recommended on high hazard soils.
WILLIAM B. HUGHES
State Resource Conservationist
ANNOSUS ROOT ROT MANAGEMENT IN ALABAMA
How to Identify Stands Affected bv Annosus Root Rot
Annosus Root Rot is a widespread disease caused by the fungus Heterobasidion annosurn,
formerly called Fornes annosus. Conks provide positive identification of annosus root rot.
Conks are fruiting bodies of the causal fungus. These fruiting bodies vary in shape from
small masses or pustules to bracket-like conks. The upper surface is light tan to dark or
reddish brown. The lower surface is white and covered with pores. The outer margin of the
lower and upper surface is white and has no pores. The colors darken after the conk passes
through the winter. Conks are difficult to tear but attempts will reveal the characteristic
leathery consistency. Pieces of litter and plants often project where a conk has grown
around these materials in the duff. The conks are connected to the stems of symptomatic
trees at about the soil line. It is best to look under trees with vines and deep litter on the
north side of the base because conks are more likely to form in more humid places. Conks
may also be found on exposed lateral roots and in humid cavities in the root and soil mass