Phaeocryptopus gaeumannii

Phaeocryptopus gaeumannii
Fruiting bodies of Phaeocryptopus gaeumannii
Scientific classification
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Pleosporales
Family: Venturiaceae
Genus: Phaeocryptopus
Species: P. gaeumannii
Binomial name
Phaeocryptopus gaeumannii
(T.Rohde) Petrak (1938)[1]
Synonyms

Adelopus gäumanni T.Rohde (1936)[2]

Phaeocryptopus gaeumannii or Swiss needle cast is a fungus that infects Douglas fir and causes yellowing of foliage and reduction in growth. It is endemic in western North American stands of Douglas fir, but was first discovered in trees planted Switzerland.[3]

The classification of Phaeocryptopus gaeumannii within the Venturiaceae has been questioned, with molecular studies placing it in the Mycosphaerellaceae (Capnodiales) near species of Mycosphaerella and Rasutoria species: Rasutoria pseudotsugae and Rasutoria tsugae.[4]

The fungus infects trees in the spring, and continues to develop over the following winter. The fungus causes yellowing (chlorosis) of the needles, with eventual necrosis and premature needle-drop. In some heavily diseased stands of trees, the only needles remaining are those of the current year, in which the disease has not yet had time to fully develop. The overall result for the infected tree is reduced growth.[5][6]

The fungus is temperature dependent within the Douglas fir range, with the highest level of infection in the warmest part of the range.[7][8] Growth reduction in the warm part of the range averages 35%.[6]

Gallery

Douglas fir needles showing the effect of Phaeocryptopus gaeumannii infection


References

  1. ↑ Petrak, Franz (1938). "Beiträge zur Systematik und Phylogenie der Gattung Phaeocryptopus Naumov". Annales Mycologici (in German) 36: 9–26.
  2. ↑ Rohde T. (1936). "Adelopus gauemannii n. sp. und die von ihm hervorgerunfene "Schweizer" Douglasienschüt.". Forst Woch Silva (in German) 24: 420–422.
  3. ↑ Boyce, J. S. (1940). "A needle-cast of Douglas fir associated with Adelopus gäumanni". Phytopathology 30 (8): 649–659. Abstract
  4. ↑ Winton, Loretta M.; Stone, Jeffrey K.; Hansen, Everett M. and Shoemaker, R. A. (2007). "The systematic position of Phaeocryptopus gaeumannii". Mycologia 99 (2): 240–252. doi:10.3852/mycologia.99.2.240. Archived from the original on 14 January 2014.
  5. ↑ Stone, Jeffrey K.; Capitano, Bryan R. and Kerrigan, Julia L. (2008). "The histopathology of Phaeocryptopus gaeumannii on Douglas-fir needles". Mycologia 100 (=3): 431–444. doi:10.3852/07-170R1. Archived from the original on 14 January 2014.
  6. ↑ 6.0 6.1 Kimberley, M. O.; Hood, I. A. and Knowles, R. L. (2011). "Impact of Swiss needle-cast on growth of Douglas-fir". Phytopathology 101. (5): 583–593. Archived from the original on 12 January 2014.
  7. ↑ Hood, Ian A. (1982). "Phaeocryptopus gaeumannii on Pseudotsuga menziesii in southern British Columbia". New Zealand Journal of Forestry Science 12 (3): 415–424. Abstract
  8. ↑ Watt, Michael S.; Stone, Jeffery K.; Hood, Ian A. and Palmer, David J. (2010). "Predicting the severity of Swiss needle cast on Douglas fir under current and future climate in New Zealand". Forest Ecology and Management 260 (12): 2232–2240. doi:10.1016/j.foreco.2010.09.034. Archived from the original on 12 January 2014.

External links