Laminated Root Rot Douglas Fir

Laminated root rot b advanced decay occasionally laminated.

Laminated root rot douglas fir. Masses of setal hyphae can been seen as a reddish brown fuzz on the upper part of this decayed wood. Surveys indicate approximately 5 of the area of highly susceptible host types in oregon and washington is out of production because of this disease. Laminated root rot is the most damaging root disease in oregon from the stand point of wood fiber produc tion. Douglas fir tree on my property that a forester tells me has laminated root rot.

This hinders its ability to suck up water and soil nutrients. It causes trees to prematurely shed their needles. Bloomberg 1990 monitored the rate of expansion of 62 laminated root rot centers for 27 years in three coastal douglas fir plantations in british columbia canada. It is the tree with the dead top.

Found in western and eastern oregon the disease is caused by the fungus phellinus weirii. Laminated root rot also known as yellow ring rot is caused by the fungal pathogen phellinus weirii laminated root rot is one of the most damaging root disease amongst conifers in northwestern america and true firs douglas fir mountain hemlock and western hemlock are highly susceptible to infection with p. Swiss needle cast is a foliage disease that affects douglas fir trees. It affects all conifer species to some degree but is most damaging to douglas fir grand and white fir and mountain.

Wood with advanced decay is brown dry and separates into cubes often with thin crust like mycelial sheets in the shrinkage cracks. Root infections eventually lead to root and lower bole decay. Decayed wood separates at the annual rings giving the disease its name. Bark beetles especially douglas fir beetle douglas fir engraver douglas fir pole beetle and fir engraver frequently colonize trees infected with laminated root rot.

The overall average rate. Fir douglas and true laminated root rot. Laminated root rot is an important tree disease of douglas fir and western red cedar in northwestern north america. Laminated root rot infects new hosts when uninfected roots of susceptible trees grow into contact with infected stumps or roots.

Weirii a few species of plants such as western white pine and lodgepole pine are. Laminated root rot laminated root rot caused by the fungus phellinus poria weirii is responsible for an annual estimated volume loss of 32 million cubic feet in the west side douglas fir type. In douglas fir swollen root stubs form when the fungus rots root ends. Among the most prevalent diseases in oregon are swiss needle cast and laminated root rot.