Brown stains which appear on the surface of sawn radiata pine cut from water-stored logs were identified as tannin-like compounds. They are derived from bacterial breakdown of flavanoid-glucosides. When timber is sawn from infected logs, the free flavanoids migrate to the wood surface as the timber dries. There, they condense and oxidise to form permanent brown discolourations. Stains occurred on sawn timber between 4 and 8 weeks of storage under water sprinklers. Kiln-drying resulted in more intense staining than did air-drying. Stain intensity was less in winter-stored logs than in summer-stored logs. Sprinkling logs with fresh water or debarking logs before storage had little consistent effect on propensity to stain

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