VEGETABLE AND FIELD CROPS 225 



Rot begins in the field, but becomes serious during stor- 

 age. The initial attack is either at the crown or root tip, 

 from which points it proceeds rapidly through the core, 

 which becomes softened and somewhat browned with a 

 rather sharp boundary between diseased and healthy tis- 

 sue. 



Fields known to be infested should be relieved of sus- 

 ceptible crops })y suitable rotation. Manure, which may 

 have become infected in any way, e.g., by feeding diseased 

 crops to stock, should be avoided. Drying of the roots 

 kills the causal organism, as does also exposure to sunlight. 

 Drying in the light is therefore equivalent to surface dis- 

 infection and serves to reduce the damage. Storage below 

 10° C. (50° F.) gives best results. 



CAULIFLOWER 



Black rot, pseudomonose (Pseudomonas campestris 

 (Pamm.) E. F. Smith). — This disease affects the cauliflower 

 in much the same way as it does the cabbage. Local 

 infection in the head often produces the effect shown in 

 Fig. 106. For discussion of symptoms and treatment, 

 see cabbage. 



Sclerotiniose. See cabbage. 



Soft rot, bacillose (Bacillus oleracea Harr.). — A soft 

 rot affecting cauliflower, cabbage, and turnips, and in 

 some cases destroying as much as 64 per cent of the crop, 

 is described by Harrison.i The disease may be identical 

 with the soft rot of carrot.^ 



1 Harrison, F. C, Ont. A. C. & E. F. Bui. 137, August, 1904. 

 • Harding, H. A., Jones, L. R., and Morse, W. J., N.Y. (Geneva) Agr. 

 Exp. Sta. Tech. Bui. 11, 1910. 

 Q 



