THE STRUMELLA DISEASE OF OAK AND CHESTNUT 



TREES/ 



BY 



F. D. HEALD and R. A. STUDHALTER, Agents, 

 Investigations in Forest Pathology, Bureau of Plant Industry, 



INTRODUCTION. 



The stud)'- of chestnut tree bHght in Pennsylvania has brought 

 to hght a serious disease of the chestnut due to an entirely dif- 

 ferent organism. The trouble is not confined to the chestnut but 

 attacks various species of oaks. The disease is obscure in its 

 early stages and in some of its more advanced phases, which 

 probably accounts lor the fact that it has not been generally 

 observed by foresters. Our recent studies reported by the senior 

 author^ lead to the belief that it is a rather widespread disease 

 and responsive for the death of many trees, both young and old. 



What was probably the same trouble was briefly described in 

 1899 by Dr. W. A. Buckhout^, as causing the death of various 

 species of oak trees, but no mention was made of the occurrence 

 of the disease on chestmit trees. While he regarded the disease 

 as of fungous origin, no definite determination of the causal 

 organism was made. The correctness of our inference that he 

 was dealing with the same trouble is based largely on the similar 

 symptomology as may be noted by comparison of our descrip- 

 tion with the following quotation: 'The black oak is particu- 

 larly subject to a disease apparently of the same nature if not 

 identical with Nectria ditissima, the canker of the apple tree. 

 The early stages of the disease are obscure and inconspicuous, 

 and one's attention is attracted only after serious injury has been 

 done. Apparently the starting point is at the base of a small 



branch, causing the death and slow decay of surrounding bark 



<oo 



rv 1. Published by permission of the Secretary of Agriculture. 



2. Heald, F. D. A little-known disease of chestnut and oak trees. Phytopathology 



4: 49. 1914. 



3. Buckbout, W. A. The undesirability of red and black oak because of fungus disease. 



Report Penna. Station, 1899 : 250-252. 



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