Root Diseases

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.

1 Under bark of root collar or of roots, white or cream-colored mycelium fans or felts, may also be found throughout bark, basal resinosus usually present --- Armillaria Root Rot

1’ No mycelium fans or felts under bark --- 2

2 On Douglas-fir, true firs or western hemlock; cream-colored to rusty brown mycelium on outside of root collar or root bark. If decayed, root sapwood or butt heartwood with pitted (small holes); decay separates easily into sheets at the annual rings --- Laminated Root Rot

2’ Not as above --- 3

3 Staining in sapwood of roots or butt (stump) cross-section --- 4

3’ Staining not seen or restricted to heartwood --- 7

4 Red-brown, brown or gray stain in crescent or broad ring of sapwood, often in heartwood as well --- 5

4’ Black or blue stain restricted to sapwood --- 6

5 Sapwood of roots with white or yellow decay, somewhat laminate or spongy, often with irregular white pockets and black flecks. In decayed stumps, pored conks with brown or gray upper surface and cream or tan lower surface sometime present. Firm, small tan mounds (button conks) sometimes present on bark of roots (especially of seedlings) --- Annosus Root Rot

5’ On Douglas-fir, true firs or western hemlock; cream-colored to rusty brown mycelium on outside of root collar or root bark. If decayed, root sapwood or butt heartwood with pitted (small holes); decay separates easily into sheets at the annual rings --- Laminated Root Rot

6 Primarily on pinyon pine, sometimes on ponderosa pine or Douglas-fir; in sapwood at root collar or in roots, black stain in concentric crescents within annual rings --- Blackstain Root Disease

6’ Black or blue stain radiating from outer sapwood inward, not in crescent pattern; In dead trees or dead parts of trees --- Bluestain of Sapwood

7 Red-brown discoloration restricted to root or butt heartwood, often in broad crescents of resinous, discolored wood --- 8

7’ Column of decay in root or butt heartwood 9

7’’ Neither staining nor decay present in roots or butt; other parts of tree affected --- Branch or Terminal Key

8 On Lodgepole pine or Engelmann spruce; Advanced decay in heartwood of roots and butt is distinctive white pocket rot with long, spindle-shaped pockets with bleached contents or hollow. Firm wood between pockets gives dcay honeycomb appearance in cross section --- Tomentosus Root Rot

8’ Common in Douglas-fir, most species susceptible; center of root dark red-brown discoloration and heavily resinous or with brown, crumbly or cubical rot --- Schweinitzii Root and Butt Rot

9 Brown rot; crumbly or cubical; in columns or decaying most of heartwood; resinous patches or crescents often present --- Schweinitzii Root and Butt Rot

9’ Decay with distinctive honeycomb appearance in cross section; Usually lodgepole pine, or Engelmann or Colorado blue spruce; White pocket rot with empty or bleached contents and firm wood between pockets --- Tomentosus Root Rot

9’’ White or yellowish, stringy or somewhat laminate decay; often with large irregular white pockets and black flecks; becoming spongy, wet in late stages of decay --- Annosus Root Rot