Potato Failures. 
By F. M. ROLFS. 
INTRODUCTION. 
The following lines are written to call the attention of 
Cthe potato growers in this state to a destructive disease of 
the potato, Rhizoctonia solani Kuhn. I am aware of the in¬ 
completeness of this report, but it is hoped that a publica¬ 
tion at this time may stimulate an interest in the subject 
and thus call forth suggestions which will be helpful in 
^working out a practical method of overcoming this disease. 
Undoubtedly this fungus has been common to the potato 
fields of America for years, and although of considerable 
economic importance it has been entirely overlooked by 
American investigators, and nothing of importance concern¬ 
ing its nature has been recorded. *Stewart and Duggar in 
1 9°P published the first account of its occurrence in America. 
European investigators have given it considerable at¬ 
tention and European literature contains a number of pub¬ 
lications on a potato disease caused by Rhizoctonia. Its 
host plants cover a wide range and a number of species 
of the fungus have been described. 
OCCURRENCE OF DISEASE. 
The stem rot of the potato plant was first brought to 
emy attention during the summer of while at the New 
York State Branch Experiment Station on Long Island. 
The potato growers in the various sections of the Island, 
complained of the early wilting or drying of the vines caus¬ 
ed by a stem rot. On visiting these sections and making 
careful observations it was noticed that the disease in many 
instances resembled the stem rot of carnations, which is 
caused by the attack of a species of Rhizoctonia . 
A microscopic examination of plants that had been re¬ 
cently killed invariably revealed an abundance of this fun¬ 
gus on the stems and roots. At least thirty plantations in 
various sections of the Island were visited and a number of 
dead plants from each field were carefully examined. Al¬ 
though other fungi were more or less plentiful on these 
stems, Rhizoctonia was constantly present both in the pith 
and on the outside of the roots and stems. These observa¬ 
tions pointed toward the conclusion that this fungus had 
* Bulletins 186 of the New York State Agricultural Experiment Sta¬ 
tion, and Cornell Experiment Station. 
