Butt rot in conifers caused by Serpula himantioides (Fr.) Karst

Seehann, G.

Serpula himantioides was found to be a causal agent of butt rot in Douglas fir [Pseudotsuga menziesii] and Japanese larch [Larix kaempferi] in northern Germany. The decay started predominantly from tap roots and main side roots and extended few meters into the stem. In final stages of rot the basal heartwood was completely destroyed and the residual width of healthy sapwood was reduced. Laboratory tests revealed a tolerance by the fungus to extremely acid substrates.