BULLETIN OF THE 



No. 203 



Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief. 

 April 30, 1915. 



(PROFESSIONAL PAPER.) 



FIELD STUDIES OF THE CROWN-GALL OF 

 SUGAR BEETS. 



By C. O. TowNSEND, 

 Pathologist in Charge of Sugar-Beet Investigations. 



KINDS OF BEET GALLS. 



There are at least two distinct but clearly related kinds of growths 

 occurring upon sugar beets which may be considered under the name 

 of galls. These have been designated as ^'tumors" and ''tubercu- 

 losis" in Bulletin No. 213 of the Bureau of Plant Industry.^ While 

 these two kinds of outgrowths are similar in external appearance, 

 especially in their early stages of development, their internal ap- 

 pearance and their subsequent behavior serve to distinguish the 

 tumor from tuberculosis. Internally, the outgrowths known as 

 tuberculosis of the beet show small, brownish, water-soaked areas, 

 as mentioned on page 194 of the bulletin cited, while the tumor is 

 free from these discolored areas. Externally, both kinds of galls 

 are usually smooth at first, but the tuberculosis gaUs eventually 

 become decidedly rough, cracked, and very dark, and finally decay. 

 This decay of the galls often causes the beet itself to rot, thereby 

 entaihng more or less loss on the grower, according to the prevalence 

 of the disease. On the other hand, the tumor remains comparatively 

 smooth, seldom cracks, does not usually decay, and frequently 

 retains its firmness until the beets are harvested. The quality of the 

 galls and their effect upon the beets from which they arise, as given 

 in this paper, relate for the most part to the tumor variety. 



DISTRIBUTION OF BEET GALLS. 



The abnormal outgrowths kno\^m in this country as crown gaUs 

 have been observed upon beet plants from time to time for more than 

 50 years. Indeed, as early as 1839 attention was called to these 



1 Smith, Erwin F., Bro^^^l, Nellie A., and Townsend, C. O. Crown-gall of plants: Its cause and remedy. 

 U. S. Dept. Agr., Bur. Plant Indus. Bui. 213, p. 105, 194. 1911. 

 82778°— BuU. 203—15 



