Black Stain Root Disease

Ceratocystis wageneri Goheen and Cobb

From: Field Guide to Diseases and Insect Pests of Idaho and Montana Forests, USDA Forest Service Northern Region, Publication Number R1-89-54

Hosts. – Douglas-fir, lodgepole pine, ponderosa pine, and eastern white pine are known to be infected in Idaho and Montana.

Distribution. – This disease has been found in relatively few locations in Idaho and Montana. All known locations in Montana are west of the Continental Divide.

Damage. – Trees are killed by the fungus growing in trachieds and blocking water conduction. Bark beetles usually attack infected trees.

Identification. – Trees with black stain root disease may have crown symptoms typical of root diseases but often they die too quickly for root disease crown symptoms to develop. In this case crowns remain full and needle length near normal, while the entire crown fades uniformly to yellow and then red. The disease is indicated by brown, or black stain in roots and root collar sapwood (fig. 69) which follows the annual rings. In cross section the stain forms concentric crescents in the sapwood (fig. 70). Presence of black stain root disease is sometimes obscured by Armillaria root rot which often attacks trees with black stain root disease.

Similar damages. – Blue stains caused by nonpathogenic or only weakly pathogenic fungi are common in dying or dead trees. Contrary to their name 'blue' stains can be black, brown, or even red. Blue stains do not follow the annual rings. They are wedge-shaped and follow the rays inward from the cambium.

Link to Table 2 – Comparison of Common Root Diseases

References.

Anonymous. 1982. For. Insect & disease identification and management. USDA For. Serv.,Northern Region; Idaho Dept. of Lands, Insect and Disease Control; Montana Dept. of State Lands, Division of Forestry. 192 p.

Bega, R. V. 1978. Diseases of Pacific Coast conifers. USDA For. Serv. Ag. Hndbk. No. 521, 206 p.

Smith, R. S., Jr., and D. Graham. 1975. Black stain root disease of conifers. USDA For. Serv., For. Pest Leaflet 145, 4 p.

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