Internationally Dangerous 

 Forest Tree Diseases 



By Working Group on International 

 Cooperation in Forest Disease Research, 

 Section 24, Forest Protection, International 

 Union of Forestry Research Organizations 



Supplement to Section 24-14, Proceedings of the 13th 



Congress, International Union of Forestry Research 



Organizations, Vienna 1961 



Miscellaneous Publication No. 939 September 1963 



U.S. Department of Agriculture Forest Service 



