Fungal resistance of panel products made of or containing materials of organic origin. Method for determination of resistance to cellulose-decomposing microfungi|Wood preservation, Testing conditions, Cellulose, Woodbased sheet materials, Control samples, Structural timber, Boards, Panels, Wood products, Specimen preparation, Fungal-resistance tests, Sheet materials, Microbiological-resistance tests, Soils, Wood, Test specimens, Water content determination, Construction materials, Biological analysis and testing