PRODUCTION OF BROWN STAIN IN HEMLOCK LOGS AND LUMBER DURING STORAGE

Hemlock brown stain is a discoloration that can develop in unseasoned logs and lumber of western hemlock and amabilis fir. This discoloratio n is a serious problem for producers of high-value Canadian lumber. Pr oduction of hemlock brown stain was monitored in freshly felled wester n hemlock trees and after storing the logs for 2 and 9 months. Saltwat er and dry land storage of logs were evaluated as conditions that infl uence colorations. Lumber sawn from the 9-month-old logs was also eval uated for color change following storage for 2 months. This study demo nstrated that brown stain was associated with extended log storage, pa rticularly in saltwater. Fungi were isolated from freshly felled trees and from logs after 2 months of storage. Dark-pigmented hyphae were a ssociated particularly with areas showing brown stain. Information gai ned from this study suggested that faster processing of western hemloc k logs into lumber could lessen the extent of brown stain problems.