LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 

 Washington, D. C, April 11, 1910. 



Sir: I have the honor to transmit herewith a paper entitled "Field 

 Studies of the Crown-Gall of the Grape," by Dr. George Grant Hedg- 

 cock, Pathologist, Investigations in Forest Pathology. 



The paper embodies the results of several years of investigation of 

 the crown-gall of the grape in the western United States, especially 

 of the susceptibility and immunity to the disease of a number of the 

 most important varieties of grapes. It is found that a few varieties 

 are resistant to the crown-gall, and that the use of the varieties 

 Rupestris St. George and Lenoir as stocks for engrafting congenial 

 nonresistant varieties affords a ready means of successfully overcom- 

 ing the effects of the disease under soil and climatic conditions favor- 

 able to such varieties. 



Studies on the congeniality of Vitis vinifera to resistant stock varie- 

 ties, and the adaptation of varieties to soil, climatic, and other con- 

 ditions, are discussed by Prof . George C. Husmann in Bulletin 172 

 of this Bureau. 



The writer of this paper is indebted to Prof. Fabian Garcia, of the 

 Agricultural Experiment Station of New Mexico, for hearty coopera- 

 tion in obtaining information as to the extent of crown-gall in that 

 Territory. 



This paper completes the work of Doctor Hedgcock on the subject, 

 but studies of the field end of this disease will be continued by the 

 Office of Fruit-Disease Investigations of this Bureau. 



I recommend that this paper be published as Bulletin No. 183 of the 



special series of this Bureau. 



Respectfully, B. T. Galloway, 



Chief of Bureau. 

 Hon. James Wilson, 



Secretary of Agriculture. 



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