Storage damage by blue stain and decay in poles before impregnation has been increasingly observed during recent years and there have been reports that salt-impregnated poles today are of lower quality because of incipient decay being increasingly common. The attacks may have started at the time of cutting and then continued during the period of seasoning at the plant, which could be as long as two years. Sub-standard impregnation has been mentioned as a reason for the decay. However, microscopic examination of samples from newly-impregnated poles has shown that attacks of blue stain as well as of brown and white rot have sometimes been of such an extent that damage by micro-organisms before impregnation was the probable reason. The aim of the present work was to illustrate the extent of blue stain and rot in poles before impregnation and to survey the methods of bark removal and storing poles during seasoning in Sweden. The production of treated poles of pine (Pinus sylvestris L.) in Sweden during 1985 was 74,300 m³ (51,200 m³ with creosote and 23,100 m³ with water-borne). The amount exported was 27,900 m³ (26,100 m³ with creosote and 1,800 m³ with waterborne CCA-type). At the time of the investigation there were nine major impregnation plants for poles in Sweden.

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