Smothering fungus

The smothering fungus, Thelephora terrestris, is a mycorrhizal fungus associated with many coniferous species. It has a wide distribution and readily invades fumigated soils. It can occasionally grow up the stems of bareroot or container-grown seedlings, particularly where dense growth shades seedling bases. This habit gives it the name, "smothering fungus." The fruiting body of the fungus initially forms a collar around the lower stem and, in serious infestations, grows upward (Figure 60), smothering the seedling. It develops and matures on the seedling or surrounding surfaces such as styroblocks. The fungus does not rot tissue; however, severe smothering could result in mortality. Management practices that reduce humidity are important. These include growing seedlings at lower densities, carefully managing irrigation, and increasing ventilation in greenhouses.

Selected References

Hacskaylo, E. 1965. Thelephora terrestris and mycorrhizae of Virginia pine. For. Sci. 11: 401-404.

Zak, B. and D.H. Marx. 1964. Isolation of mycorrhizal fungi from roots of individual slash pines. For. Sci. 10: 214-222.

Look Alikes

Other Fungi

Insects

Environmental

Gray mould
Rosellinia blight

 

Overcrowding

Summary

Smothering Fungus

Principal, locally grown hosts

Host age and season when damage appears

 

Nursery type and location

 

 

 

     

Bareroot

 

Container

 
 

Age

Season

Coastal

Interior

Coastal

Interior

All species

1+0
2+0

Throughout growing season

Yes

Yes

Yes

Yes


Figures

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Click on this image to see a larger version     Figure 60. Smothering fungus on container-grown spruce.