Cedar Laminated Butt Rot
From Bugwoodwiki
Hagle, S.K; S. Tunnock; K.E. Gibson; and C.J. Gilligan. 1987. Field Guide to Diseases and Insect Pests of Idaho and Montana Forests. U.S. Department of Agriculture, Forest Service. State and Private Forestry, Northern Region. Missoula, Montana. Reprint 1990. Publication Number R1-89-54.
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Contents |
Hosts
Western redcedar. Douglas-fir and grand fir are most susceptible. Western hemlock and subalpine fir are less susceptible and other conifers in northern Idaho and Montana are tolerant or resistant.
Distribution
Range of host in Idaho and Montana.
Damage
Heartrot of stem; often resulting in total cull. Mortality or windthrow. Decays roots and kills cambium of roots and root collar. Mortality occurs in large disease centers and small groups. Infected trees are often attacked by bark beetles as well.
Identification
The rot forms concentric rings of variously rotted heartwood. These concentric rings separate easily into thin sheets. The sheets are pitted with tiny (1/16 in.) holes. Patches of brown, fuzzy mycelium are often found in the decay; when magnified they resemble tiny spears (called setae). Infected trees have typical root disease crown symptoms. Most diagnostic is the thin layer of cream-colored mycelium coating the outside bark of infected roots (fig. 66). Fuzzy, cinnamon-colored mycelium is often found in bark cracks with the cream-colored mycelium. Infected trees occasionally have some basal resinosus. Freshly cut stumps often have brown stains visible in patches on the surface associated with the early stages of decay. Decayed wood separates easily along the annual rings and is extensively pitted with small white or cinnamon-colored pockets. The disease may develop as a butt rot in some trees long before the trees are finally killed.
Similar damages
Cedar brown pocket rot is most often confused with this damage. The decay types are distinctive when examined closely. Armillaria root rot also causes basal resinosus but white mycelium is present under the bark in the cambial region rather than on the exterior of roots.
Table Comparison of Common Root Diseases
| Fungus | Hosts | Basal Resinosus | Decay | Other Distinguishing Characteristics |
|---|---|---|---|---|
| Armillaria ostoyae | 1. DG, GF, saping pines 2. Other conifers | Yes | White or yellowish, stringy with black zone line and rhizomorphs | Thick fan-shaped felts of white mycelium in cambium |
| Phellinus
wirii | 1. DF, GF
2. Other conifers | Yes | Laminated, separating at annual rings, pitted with pinhead-sized holes | Cream-colored mycelium on outer bark of roots and root collar under duff. Cinnamon-colored mycelium often in bark cracks with cream cycelium. |
| Phaeolus schweinitzii | 1. DF
2. Other conifers | No | Brown cubical rot of root and butt heartwood | Small roots with red-brown resinous heart; galled roots; large brown, velvety conks with green or brown pore layer on underside produced on ground or base of tree. |
| Fomes annosus | 1. DF, GF
2. SAF, WH, PP, WRC, WWP | No | White or yellowish, stringy to somewhat laminate. White pockets with black flects sometimes present | Conks shelving or flat on sides in hollow stumps. Conks have brown upper surface and white lower, pored surface with brown, non-pored margin. Cream-colored mounds (button conks) below duff on seedlings. |
| Ceratocystis wageneri | 1. PP,LPP, DF
2. ? | No | No decay produced | Black or brown stain in sapwood follows annual rings. |
Gallery
 Photo by USDA Forest Service Archive, USDA Forest Service, Bugwood.org |
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. Handbk. No. 521, 206 p.
- Boyce, J. S. 1961. Forest Pathology. McGraw-Hill Book Co., New York, NY. 572 p.
- Nelson, E. E., N. E. Martin, and R. E. Williams. 1981. Laminated root rot of western conifers. USDA For. Serv., For. Ins. & Dis. Leaflet 159, 6 p.
- Childs, T. W. and E. E. Nelson. 1971. Laminated root rot of Douglas-fir. USDA For. Serv., For. Pest Leaflet 48, 7 p.
- Hepting, G. E. 1971. Diseases of forest and shade trees of the United States. USDA For. Serv. Ag. Hndbk. No. 386, 658 p.
