PLATE I 



I. — Influence of amount of infestation on injury from tobacco rootrot: A, All unin- 

 fested soil;" B, three-fourths uninfested soil; C, one-half uninfested soil; D, one- 

 fourth uninfested soil; E, all infested soil. 



II, III. — Influence of moisture content of soil on the amount of injury done by the 

 tobacco rootrot; II, infested soil; III, iminfested soil (control series) — 



I A, one-fourth saturation infested soil; 



2 A, one-half saturation infested soil ; 



3 A, three-fourths saturation infested soil ; 



4A, full saturation infested soil; 



iB, one-fourth saturation uninfested soil; 



2B, one-half saturation uninfested soil; 



3B, three-fourths saturation uninfested soil; 



4B, full saturation uninfested soil. 

 IV. — Influence of soil temperature on the growth of tobacco in infested soil (jars 

 to left of temperature labels) and in uninfested soil (jars to right of temperature labels) 

 at temperatures of approximately 13°, 17°, 23°, 26°, and 36° C. 



