Bui. 1029, U. S. Dept. of Agriculture. 



Plate I. 



Cabbage Black-Leg. 



^4.— Total loss of crop due to black-leg in spite of seed treatment with a 1:256 formaldehyde 

 solution for 30 minutes. This field is typical of the epiphytotic of black-leg which developed 

 in the Racine, Wis., district in 1918. 



B. — The importance of seed-bed infection as influencing the subsequent development of black- 

 leg in the field. The major portion of this field was planted from a healthy seed bed, but 

 occasional lots of plants were used from a diseased bed. The row in the center of the illus- 

 tration was planted with the latter. Note that practically every plant has wilted, while 

 there is no evidence of damage by spread of the fungus from these plants to the adjacent rows. 

 Photographed at Racine, Wis., September 30, 1917, about 12 weeks after transplanting and 

 shortly before harvest. 



