On the Causes of Yellow Discolorations of Oak Heartwood (Quercus Sect. Robur) During Drying

1991

S. 79-85

5 Abb., 2 Tab., 31 Lit. Ang.

Unselbständiges Werk

200031962

Yellow discolorations in oak heartwood during drying lead to serious reduction in wood value. In order to develop a specific prophylactic treatment preventing these discolorations it was indispensable to detect the causes for these reactions. The yellow discolorations were identified to be caused by the mold fungus Paecilomyces variotii Bain. and the reacting compounds are hydrolysable tannins. These specific heartwoods compounds were found in Quercus species of the Section Robur and also in Castanea sativa Mill., but not in Quercus species of the Secton Rubrae. Lumber has to be stored under cover while exposed to wind and protected during drying to prevent mold growth.