34 



Journal of Agricultural Research 



Vol. VI, No. I 



Table III showvS the average number of hours a day that the relative 

 humidity remained above 60 at Madison and at Rocky Ford. 



Table III. — Average number of hours a day that the relative humidity was above 60 at 

 Madison, Wis., and Rocky Ford, Colo., during ihesummer of igi4and igij, respectively 



June 16 to 30 



July 



August 



September i to 6 



Seasonal average 



Madison, 

 Wis. (1914). 



Hours. 

 19.4 



17-3 

 16.6 

 18.0 



17.4 



Rocky Ford, 

 Colo. (1913). 



Hours. 

 10.8 

 14.2 

 14. I 

 II- 3 



13-4 



Fig. s. — Curves of the maximum and minimum temperatures among sugar-beet plants and at the Weather 

 Bureau station, and the seasonal rainfall records at IMadison, Wis., in 1914, and the number of hours 

 that the humidity remained above 60 aipong the sugar-beet plants in the field at Madison, Wis., in 

 1914, and at Rocky Ford, Colo., in 1913. 



The greater average number of hours of high humidity at Madison 

 accounts for the periods of extreme infection which occurred there when 

 the fungus was present. Here leaves badly infected with Cer cos para 

 heticola and entirely covered with conidia were found at times, but this 

 condition was rarely seen at Rocky Ford. There were numerous cases 

 of cotyledon infections also at Madison, the high humidity early in the 

 season favoring their occurrence; but no such infections were found at 

 Rocky Ford. 



