Root Diseases

Laminated Root Rot sulphurascens Pilát [ (Murr.) Gilb.] Hosts-- Douglas-fir and grand fir are most susceptible. Western hemlock and subalpine fir are less susceptible and other in northern Idaho and Montana are tolerant or resistant. Also see: Cedar laminated butt rot, p. 26.

Distribution-- The range of Douglas-fir or true firs in northern Idaho and northwestern Montana.

Damage-- Mortality or windthrow. Decays roots and kills cambium of roots and root collar. Trees of all ages are killed by girdling the cambium and decaying the sapwood. Mortality occurs in large disease centers and in small groups. Infected trees often are attacked by bark beetles as well.

Identification-- Infected trees have typical root disease crown symptoms. Freshly cut stumps often have brown or red-brown stain in the sapwood and outer heartwood indicative of the early stages of decay (fig. 124). Conks are rare and indistinct (fig. 125). Most diagnostic is the thin layer of cream- to dark yellow-colored mycelium covering the outer bark of infected roots (fig. 126). Fuzzy, cinnamon-colored mycelium often occurs in bark crevices along with the cream-colored mycelium. Infected trees occasionally have some basal resinosus. Decayed wood separates easily along the annual rings and is extensively pitted with small white- or cinnamon-colored pockets (fig. 127, 128). Trees with rotten roots are prone to windthrow. Some trees develop butt rot from this disease long before they are killed.

Similar damages-- Armillaria root disease also causes basal resinosus but white mycelium fans of Armillaria are present under the bark in the cambial region rather than on the exterior of roots.

References-- See full guide. Figure 124. Brown stain is sometimes seen in the sapwood or outer heartwood of trees with .

Figure 125. Conks are rare. They grow on a root or fallen stem of a tree killed by laminated root rot. They are thin, leathery when fresh and friable with age, light weight, yellow to cinnamon brown with small pores. 82 Root Diseases

Figure 126. Cream- or yellow to cinnamon-colored mycelium is found on the outer bark of roots with laminated root rot.

Figure 127. Decay from laminated root rot separates easily at the annual rings and is pitted with tiny holes. Cinnamon-brown mycelium and and tiny hair- like hyphae (setal hyphae) are often found in the decay.

Figure 128. Decay from laminated root rot has distinctive, pinhead-sized round pits.

83 Root Diseases

Table 3. Comparing Important Root Diseases.

OTHER BASAL HOSTS DECAY DISTINGUISHING RESINOSUS CHARACTERISTICS

,FW,FG,FD SE,FAS,FR roetihW depahs-nafkcihT Armillaria gnilpas ,hsiwolley etihwfostlef seY ostoyae senip htiwygnirts mycelium under senilenozkcalb bark srefinocllA

deroloc-maerC ,detanimaL retuonomuilecym FG,FD tagnitarapes stoorfokrab Phellinus ,sgnirlaunna ;ffudrednu seY sulphurascens rehtO htiwdettip wolley-nomannic srefinoc dezis-daehnip krabnimuilecym seloh maerchtiwskcarc muilecym

rognivlehssknoC ,FG,FD nidesserppa ,FW,FAS rospmutswolloh Heterobasidion FR occidentale roetihW stoorno rehtO ,hsiwolley ;dnuorgrednu srefinoc otygnirts ecafrusreppu oN tahwemos rewol,nworb ;etanimal rolocmaercderop etihwralugerri -nonnworbhtiw Heterobasidion PP htiwstkcop ;nigramderop skcelfkcalb deroloc-maerc irregulare Other pines rarely nottub(sdnuom gnildeesno)sknoc stoor

htiwstoorllamS nworb-der center;suoniser egral;stoordellag FD lacibucnworB ytevlev,nworb Phaeolus oN dnatoorfotor neerghtiwsknoc schweinitzii rehtO doowtraehttub eropnworbro srefinoc e;disrednunoreyal p nodecudor eertrodnuorg esab

kradrokcalB Leptographium PP,PNP edoN c ya niniatsnworb oN wageneri decudorp swollofdoowpas FD,PL sgnirlaunna

ronworb-deR niniatsnworb 5-2sknoc;toor PPL,SB,SE tekcopetihW Onnia otwolley,sehcni ,egralhtiwtor tomentosa oN reppunomannic rehtO s depahs-eldnip trohshtiw;ecafrus srefinoc stekcopytpme natotmaerc;epits rewoldiorop ecafrus

BS=Colorado blue spruce, DF=Douglas-fir, ES=Engelmann spruce, GF=grand fir, LPP=lodgepole pine, PP=ponderosa pine, PNP=pinyon pines, RF=red fir, SAF=subalpine fir, WF=white fir. 77 Stem Decay

Table 1. Comparison of Common Heartwood Rots.

FUNGUS HOSTS CONKS

Shape Upper Lowe r and surface surface Context Location

Echinodontium GF, WH, Tan; teeth tinctorium Hoof, under Brown, Orange SAF branch woody projecting Indian paint downward

DF, LPP, Phe llinus pini WL Hoof or flat Dark Cinnamon to Cinnamo n Pini or Other on bark brown tan red ring rot conifers

Onnia ES, LPP Mushroom- Gold to tomentosa like with brown, Tan to gold, Gold, leathery cap velvety; brown with brown with Other and central age; pores. age Tomentosus conifers 1-4 inch root disease stalk. On diameter ground

Phaeolus DF Non-woody; Green when schweinitzii Brown, fresh, brown Brown thick shelf or velvety Other on ground with age; Root & butt rot conifers large pores

Fomitopsis WL, PP Hoof or Ye llow, Yellow- officinalis cylindric, Ye llow or white; white, or white; pored Other large cream chalky Brown heartrot conifers consistency

Fomitopsis Ve ry Brown, Cream; pinicola All dead common; gray, red Cream; conifers corky thick shelf or band at small pores consistency Red belt fungus hoof margin

Heterobasidion GF, ES, Thin hoof or Cream; spp. WH, WPP, flat on bark, small pores; Leathery Gray or when fresh, SAF, DF inside hollow brown margin Annosus root stumps or on brown with woody disease PP roots age with age

Phellinus Conks very GF, DF, Tan; brown sulphurascens rare; thin, flat with age; WH on bark; light none Brown or SAF fuzzy setal yellow-tan Laminated weight, brittle hyphae root rot with age

Phellinus Conks are uncommon. Phellinus weirii (p. 26) and we irii P. sulphurascens (p. 82-83) are differentiated WR C mostly on the basis of host, although there are Cedar laminated butt microscopic differences in conks and cultural rot characteristics.

Postia Conks rare; White or sericeomollis ve ry thin, flat White or cream; WR C on bark or none cream, small very thin; Cedar brown decayed pores brittle with pocket rot wood; bitter age

Host key for Table 1 (p. 34): DF=Douglas-fir, ES=Engelmann spruce, GF=grand fir, 34 LPP=lodgepole pine, PP=ponderosa pine, SAF=subalpine fir, WH=western hemlock, WL=western larch, WWP=western white pine, WRC=western redcedar Stem Decay

Table 2. Decays of Common Heartwood Rots.

FUNGUS DECAY NOTES

Echinodontium Ye llow to orange, stringy; Conks common tinctorium confined to heartwood

Red-brown discoloration in heartwood; pronounced white, spindle-shaped pockets with Punk knots and conks firm brown wood between; common becoming stringy, white decay in most advanced stages

Root disease; fruiting Pronounced white or hollow Onnia tomentosa bodies leathery, pockets, honeycomb mushroom-like, and rare appearance in cross section in this region

Brown cubical decay of stem Root disease; conks and root heartwood; thin, common on ground, Phaeolus schweinitzii resinous felts may be present occasional on butt; dark in shrinkage cracks of decay red-brown heart in small roots

Brown cubical decay of stem Conks rare; infections Fomitopsis officinalis heartwood only; thick, white, generally high in tree; mycelium felts in shrinkage not originating from cracks roots

Brown cubical decay of both Dead trees and stumps; sapwood and heartwood; decay not restricted to Fomitopsis pinicola forms crumbly decay with heartwood; conks firm cubes common

Root disease; butt Heterobasidion White rot; somewhat heartrot common in old laminating, stringy, with grand fir, hemlock, occidentale and irregular white pockets and H. irregulare spruce, cedar, and small black flecks ponderosa pine

Decay is distinctly laminating Root disease; butt Phellinus weirii along the annual rings; tiny heartrot common in live and white pockets or hollow pits grand fir, hemlock, P. sulphurascens throughout; often filled with white pine, and cedar cinammon-brown setal hyphae (comments in Table 1)

Brown cubical decay in large Heartrot very common Postia sericeomollis pockets (several inches to in western redcedar several feet in length)

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