97 



throwing tissue of the host. It would therefore follow that the growing corn 

 plants are s^uscejuible to infection during the greater part of their growth, or 

 until the fertilization of the pistils. 



Realizing tiie 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 asi<ie for the experiment. In ordei to avoid 

 any })ossibility of infection through smutted seed, a portion of the seed was 

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

 bonate solnti')n. and a third with hot Avater, while a fourth jjortion was infected 

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

 sections, as follows: 



Section I. Seed untreated. 



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



Section III. Seed treated with ammoniacal copper carbonate solution one 

 iiour. 



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



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

 spores. 



The plat was planted May J8th, 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 knapsack sprayer, the one with P>ordeatix mixture and the other witii 

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

 as will be seen bv the following diagram: 



Sec. I. 



Sec. II. 



Sec. III. 



Sec. IV. 



Sec. V. 



