97 



growing tissue ot tlie host. It would therefore follow that the growing corn 

 plants are susceptible to infection during the greater part of their growth, or 

 until the fertilization of the pistils. 



Realizing the importance of ascertaining some method for the prevention of 

 the smut, the botanical department of the Indiana Experiment Station undertook, 

 during the past season (1895), to carry out an experiment having as its main 

 object the spraying of the plants with the best known fungicides. A portion of 

 one of the Station cornfields was set aside for the experiment. In order to avoid 

 any possibility of infection through smutted seed, a portion of the seed was 

 treated with a copper sulphate solution, another with an ammoniacal copper car- 

 bonate solutiMU. and a third with hot water, while a fourth portion was infected 

 with germinating smut spores. The experimental plat was divided into five 

 sections, a? follows : 



Section I. Seed untreated. 



Section II. Seed treated with copper sulphate solution one-half hour. 



Section III. Seed treated with ammoniacal copper carbonate solution one 

 hour. 



Section IV. Seed treated with hot water at 60° C. for five minutes. 



Section Y. Seed dipped in a nutrient solution containing germinating smut 

 spores. 



The plat was planted May 18th, and on June 8th when the plants were about 

 six inches high, two cross sections containing five rows each were sprayed by 

 means of a kna))sack sprayer, the one with Bordeaux mixture and the other with 

 ammoniacal copper carbonate. This divided the plat into twenty-five lesser ones, 

 as will be seen by the following diagram: 



Sec. I. 

 Sec. II. 

 Sec. III. 

 Sec. IV. 

 Sec. V. 



\V 



