26 



Journal of Agricultural Research 



Vol. VI- No. I 



Table II. — Effect of desiccation and overwintering on the viability of Cercospora beticola 

 in infected sugar-beet tops under field conditions at Rocky Ford, Colo., and Madison, 

 Wis. — Continued 



These experiments and observations made in the field during several 

 spring and summer months showed that on leaves slightly protected on 

 or near the surface of the ground during the winter C. beticola can live a 

 sufiEicient length of time to be a source of infection for the succeeding 

 sugar-beet crop and that the fungus is entirely killed by planting time 

 when the infected material is plowed under to a depth of 6 to 8 inches in 

 the fall. 



AIR AND SOIL TEMPERATURES AT ROCKY FORD, COLO. 



WIS. 



AND AT MADISON, 



Comparison of the air and soil temperatures which prevailed during 

 the experiment at Rocky Ford and Madison showed a wide difference. 



