274 



DISEASES OF ECONOMIC PLANTS 



While this disease as caused by Rhizoctonia has long been 

 known in Europe, especially in Germany, no record of it 



h'la. 122. — Potato attacked by Corticium. After Rolfs. 



was made in America until 1891. Since that date it has 

 been noted upon many hosts in many states. See p. 61. 



