110 Report oF THE BoTANIST OF THD 
ON THE POTATO. 
(Solanum tuberosum.) 
Although a Rhizoctonia’ disease of potatoes has long been com- 
mon in Europe, especially in Germany, where it is known under 
the names “ Grind” and “ Pockenkranheit,” there is, so far as 
we are able to ascertain, no record of the occurrence of Rhizoe- 
tonia on the potato in America. Yet our observations indicate 
that potatoes in the United States may be quite generally in- 
fested by a species of Rhizoctonia, as the subsequent discussion 
will demonstrate. 
The occurrence of this fungus upon potatoes was first brought 
to our attention by Messrs. F. A. Sirrine and F. M. Rolfs, who 
reported having found it on potato stems collected in the vicin- 
ity of Jamaica on Long Island. In the latter part of July the 
writers visited Long Island and examined several potato fields 
in the vicinity of Jamaica and Floral Park. A little Riizocienia 
was found on the potato stems in all of the fields examined, but 
it was impossible to determine whether the plants had suffered 
any injury from its presence. Unfortunately, the potato tops 
were nearly all dead at that time, the varieties grown in that 
locality being almost all early varieties. A few tubers were 
examined but nothing found. On this visit we also had the ; 
opportunity of examining some diseased potato stems collected 
on Staten Island by Miss Emma Sirrine, and found them infested 
with Rhizoctonia. A few days later Mr. Rolfs found it at Matti- 
tuck, Cutchogue and East Hampton, in the eastern part of Long 
Island. Here it occurred on late potatoes, and, in one instance 
at least, there was good evidence that it had killed a consider- 
able number of plants. It was also found at Wading River. 
There has been much complaint about the premature dying of 
potatoes on Long Island the past season. What part Rhizoctonia 
played in this trouble is not certainly known, but probably it 
was not an important one. Later, the Rhizoctonia was found on 
potato stems in many fields about Geneva, Phelps, Lodi and Oaks 
Corners. 

i * Rhizoctonia solani Ktihn, 
