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A PRELIMINARY STUDY OF ROOT DISEASES IN 

 ".."Z 3TERN WHITE PINE 1_7 



By 



John Ehrlich 



Assistant Professor of Forestry, University of Idaho 



For many years various individuals have made scattered observations on 

 the existence of root diseases in western white pine ( Pinus monticola ) and 

 associated species of all ages, and the impression has grown that these 

 diseases may influence the future management of western white pine. LacKing 

 definite information on the incidence, importance, and identity of these 

 diseases, and on their possible relation to site, weather, or mountain-pme- 

 beetle ( Dendroctonus mcnticolae ) attacks, a preliminary investigation was 

 undertaken in the summer of 1938. 



Purposes were to: (1) develop a tentative field procedure suited to 

 discovery of root diseases in extensive tree examinations; (2) learn to 

 diagnose the root diseases in the field; (3) obtain, by preliminary extensive 

 tree examinations in selected drainages, information on root diseases regard- 

 ing prevalence, possible relation to site and tree age, external symptoms in 

 relation to degree of infection, and the value of symptoms in extensive tree 

 examinations; (4) determine whether there is a relation between root diseases 

 and infestation by the mountain pine beetle. 



. r ork was restricted to western white pine in certain areas on the 

 Coeur d'Alene National Forest, Idaho. Except for beetle-killed trees, ex- 

 amination was limited to individuals in the upper crown story (dominant and 

 codominant). These trees were examined for evidence of root diseases, and 

 the associated fungi were isolated and cultured. Only diseases beginning in 

 the bark and outer sapwood were studied. 



1/ A cooperative project of the Northern Rocky Mountain Forest & Range 



Experiment Station, the Forest Insect Laboratory at Coeur d'Alene. and the 



University of Idaho School of Forestry. It was planned by Kenneth P. Davis, 



James C. Evenden, and the author, and carried out by Charles A Wellner , 



IT. D. Bedard, and the author, assisted by Loren K. Baker, William B, Petersen, 



T. T. Terrell, Stewart E. Frown, George R. Falmestoek, and GOG enrollees* 



This paper is condensed from an experiment station office report entitled 



"A Preliminary Study of Root Diseases in the Western White Pine Type if , 



June SO, 1939. (A copy of this report may be borrowed on application to the 



author, School of Forestry, Moscow, Idaho, or to the Northern Rocky Mountain 



Forest & Range Experiment Station.) 



