PLATE 26 



A. — A section through a sweet potato partially decayed by the footrot fungus, 

 Plenodomus destruens. 



B. — Sweet-potato scurf, caused by Monilochaetes infuscans. The number of infec- 

 tions is shown by the black spots on the surface. 



C. — A sweet potato entirely co^.'ered with scurf. In infections as bad as this the 

 potato shrinks and finally dries up, becoming eventually worthless. 



