96 Report of the Botanist of the 



The treated half-acre yielded 2,660 lbs. more than the check. 

 This is at the rate of 5,320 lbs. or over 2^ tons per acre. How- 

 ever, this difference can not have been the result of the treat- 

 ment. Close observation led to the conclusion that neither the 

 check nor the treated half-acre was materially injured by the 

 disease. The plants on the check, which was next the river, were 

 considerably injured by muskrats and it is believed that the dam- 

 age was sufficient to account for the difference in yield. 



Because of the small amount of disease this experiment teaches 

 very little as to the value of the treatment ; but it does show that 

 it is possible to secure a fair crop of cabbage (12 tons per acre) 

 on land on which the disease has been previously destructive. 



In ipoo. — The field used for the experiment in 1900 was the 

 same as that used in 1899. The variety of cabbage, Danish Ball 

 Head, was also the same. Previous to planting, the seed was 

 soaked for 15 minutes in a i-iooo corrosive sublimate solution.^ 

 The seedlings were inspected June 19 and seemed to be wholly 

 free from black rot. They were transplanted July 3 and 4. As 

 in 1899, the field was divided crosswise into two equal parts — one 

 part to be treated and the other part to be used for a check. 



The first treatment was made on August 9 and repeated once 

 a week thereafter until September 19. In all, seven treatments 

 were made. At each treatment all leaves showing any indication 

 of the disease whatever were removed and placed in a pile at the 

 margin of the field. Afterward, they were counted and carefully 

 examined for evidences of black rot. A record was kept of the 

 number of leaves showing definite signs of black rot; also of the 

 number of whole plants which it was necessary to remove because 

 of the disease having gained access to the stem. All these data 

 are given in the following table: 



8 The seed was treated with corrosive sublimate as a precaution against possible 

 infection by germs on the seed. In experiments made by the writers cabbage seed 

 soaked for one hour in a i-iooo solution of corrosive sublimate and afterward rinsed 

 with distilled water has germinated quite as well as untreated seed. It is safe to say 

 that a 15-minute treatment of this kind will result in no injury to the seed, 



