4. Symptoms include: Chlorotic (yellow) needles “Stress” cone crop Reduced height growth

8. Windthrow, snags and stubs

10. Fungi spread primarily through and along roots.

12. Armillaria root disease caused by A. ostoyae

13. Armillaria ostoyae A. mellea A. gallica A. nabsnona A. gemini A. calvescens A. cepistipes XI A. sinapina NABS IX, X Causal Agents:

14. Symptoms and signs: - Resin on the bark surface - white mycelial fan

15. Armillaria root rot

16. Armillaria travels through the soil via rhizomorphs

17. Species susceptibility to A. ostoyae Severely damagedModerately damagedSeldom damaged East-side Douglas-fir Grand fir White fir West-side Douglas-fir Ponderosa pine Lodgepole pine Western white pine Sugar pine Pacific silver fir Noble fir Subalpine fir California red fir Western hemlock Mountain hemlock Engelmann spruce Sitka spruce Western redcedar Western larch Incense cedar Port Orford cedar

18. De-laminated wood of laminated root rot

19. Phellinus weirii on bark of infected root

20. Ectotrophic mycelium Setal hyphae (red whiskers)

21. Fruitbody of Phellinus weirii

22. Susceptibility to laminated root rot: Highly susceptible: Douglas-fir Grand fir Mountain hemlock Intermediately susceptible: Subalpine fir Western larch Tolerant: Lodgepole pine Western white pine Resistant: Ponderosa pine Western redcedar Immune: All hardwoods are immune

23. Annosus root disease Heterobasidion annosum

27. Spores of asexual form of H. annosum on infected wood

29. Annosus root disease found on all western conifers Primary concern is on: -true fir (s-type) -hemlock (s-type) -pine (p-type)

31. Infection in a root system: Infection level Years since infection death decay total root colonization 100% Armillaria Phellinus

34. Control strategies include: Reducing inoculum - < 30% slope - low hazard for mass wasting, erosion, compaction, etc.

35. 1977 1987 1992 2002

36. Severely damagedModerately damagedSeldom damaged East-side Douglas-fir Grand fir White fir West-side Douglas-fir Ponderosa pine Lodgepole pine Western white pine Sugar pine Pacific silver fir Noble fir Subalpine fir California red fir Western hemlock Mountain hemlock Engelmann spruce Sitka spruce Western redcedar Western larch Incense cedar Port Orford cedar Control strategies (cont.): - Alternate species *no difference in susceptibility in trees less than 15 years old

37. Wildfire: - has little effect on belowground Armillaria sp. - may displace fire-intolerant hosts Strategies (cont.);

38. - Fertilization *Nitrogen - may delay symptoms *Potassium – alters root phenol:sugar

39. Strategies (cont.): - Chemical agents *effectiveness demonstrated on single stumps. *curatives likely uneconomical.

40. - Biological control Hypholoma fasciculare Other strategies: * Operational effectiveness not yet proven. *Inadequate delivery. *No agents yet registered.

41. Stand development

42. Chemical control with Sporax R or Tim-Bor R recommended on: -dry pine sites -all true fir sites -mixed conifer sites where true fir is favored Minimum stump size for treatment is ca. 10 inches

43. Compares: - future stand conditions and productivity. - effects of inoculum on management objectives. - effects of silvicultural prescriptions.