The present invention relates to a method for reducing wetwood content in green lumber by a treatment with a selected fungal species, such as Phlebiopsis gigantea or Gliocladium roseum, prior to kiln drying. In the laboratory conditions, the biological treated boards reduced wood moisture content (MC) by 22-37% more than untreated boards. The time required for drying biological treated boards was approximately reduced by 10% compared with untreated controls, and by 33% compared with freshly-saw lumber. After drying, the biological treated boards reduced the total deformation with stain, warping and checking by 14-25%.
