RESEARCH SUMMARY 



Clearcut areas regenerated to western hem lock 'and Sitka spruce in 

 southeast Alaska were surveyed for damage by Sirococcus shoot blight. 

 A disease index was calculated for potential crop trees. All Western 

 hemlock regeneration was infected. Disease severity was greater in 

 suppressed and intermediate than in dominant and codominant crown 

 classes. Mortality and severe top-killing were restricted to suppres- 

 sed and intermediate crown classes. Disease severity was greater in 

 lower than in the upper crown of potential crop trees. Terminal leader 

 kill in potential crop trees was common. Direct measures of disease 

 control are not recommended. 



