New York AGRICULTURAL EXPERIMENT STATION. 219 
Here, the stem was infested by a fungus having whitish mycelium 
and compact, black sclerotia. (See Plate XXVI, fig. 5.) In one por- 
tion of the field, lower and wetter than the rest, there were small 
areas on which nearly all of the plants were diseased. On some 
of the stems the white mycelium was abundant. No spores of any 
kind were found, but sclerotia were plentiful. The sclerotia were 
but loosely attached to the stems so that in extricating the diseased 
stalks many of the sclerotia would be knocked off. Usually, the 
diseased section of the stem was a foot or more from the root and 
not in contact with the ground. 
The fungus causing the disease was supposed to be the Sclero- 
tinia trifollorum Eriks. given in all the text books on plant diseases 
as the cause of a stem rot of clover®? and which is said to attack 
also alfalfa.° However, Prof. R. E. Smith, to whom specimens of 
the fungus were sent for identification, reported that the sclerotia 
are entirely similar to those of Sclerotinia libertiana and that they 
produce a Peziza form which leaves no doubt that the fungus really 
is S. libertiana.™ 
In 1902 further observations were made on the alfalfa wilt dis- 
ease in the same field. On June 9 of that year only an occasional 
affected stalk could be found; but by June 18, just before the first 
cutting, there were large areas on which over 50 per ct. of the 
stalks were killed by the disease. Where the plants were lodged 
the stems were mostly brown and many of them were brittie. The 
lower leaves were all dead, being frequently fastened together and 
to the diseased stems by the Sclerotinia hyphe. Often the hollow 
stems were filled with mycelium and sometimes they contained also 
sclerotia about the-size and shape of a wheat kernel. (See Plate 
XXVI, fig. 5.) At the time of the second cutting (August 1) the 
field was entirely free from disease. The alfalfa was of the Tur- 
kestan variety. This field was completely killed out by the hard 
winter of 1903-4, but it was immediately reseeded. No diseased 
stalks were found in 1905 and only a few in 1906 and 1907. 
Another small field on the Station farm seeded in the spring of 
1906 showed traces of the wilt disease in 1907. Six stalks badly 
° The occurrence of such a disease of crimson clover in America has 
been recorded by Chester (14, p. 84) and Halsted (N. J. Sta. Rpt. for the 
vear 1897:314). The writers observed a Sclerotinia crown-rot of red clover 
at Phelps, N. Y., in roor. 
® Prillieux (80, 2:419). 
* Smith (96, p. 404). 
