Library 
LIBRARY 
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CEREAL CROPS ft OISEAS^F^ INVESTI6AT10NS 
Vol. XXXI Washington, D. C., October 1,1925 No. 7 
SCLEROTINIA SPECIES CAUSING DECAY OF VEGETABLES 
UNDER TRANSIT AND MARKET CONDITIONS 1 
By G. B. Ramsey 2 
Associate Pathologist , Cotton , Truck , and Forage , Crop Disease Investigations , 
Bureau of Plant Industry, United States Department of Agriculture 
INTRODUCTION 
Sclerotinia sclerotiorum (Lib.) Massee (Sclerotinia libertiana Fckl.) 3 
has long been recognized as an important pathogene in Europe. As 
early as 1886 DeBary (2) 4 made a comprehensive study of this fungus 
and showed that it was able to produce disease in a variety of plants. 
In America, apparently, no reference was made to this fungus until 
about 1890, when it was found associated with lettuce diseases of the 
type called “drop.” It remained for R. E. Smith (28), however, to 
definitely establish, in 1900, the causal relationship of S. libertiana to 
lettuce “drop” and to clear up much of the misunderstanding 
regarding the life history of this fungus. Previous to this time 
several diseases of this type were fairly well known, but the causal 
organisms had not been established. This is shown by the articles of 
Humphrey (17), Selby (26), Stone and Smith (80), and Ramsey (25). 
Undoubtedly Sclerotinia, Pythium, Botrytis, and Rhizoctonia were 
individually and collectively responsible for most of the diseases 
described by these investigators. 
PURPOSE OP STUDY AND SOURCE OF MATERIAL 
At the present time it is found not only that Sclerotinia libertiana 
and related species are causing enormous damage in the field, but also 
that these fungi are the cause of some of the worst storage and transit 
troubles. It was with the purpose of becoming better acquainted 
with the latter type of decay and the causal organisms involved that 
the present work was undertaken. 
In this study four main objects were kept in view: (1) To collect 
a large number of cultures from all available hosts and to make 
morphological and physiological studies, to determine, if possible, 
1 Received for publication Oct. 1, 1924; issued December, 1925. 
Contribution from the Research Laboratory on Market Diseases of Vegetables and Fruits, Bureau of 
Plant Industry, United States Department of Agriculture, and the Botany Department of the University 
of Chicago, cooperating. > 
2 The writer is greatly indebted to Dr. Geo. K. K. Link of the University of Chicago for valuable sugges¬ 
tions and for criticism of the manuscript. Thanks are also due Prof. H. H. Whetzel of Cornell University 
for suggestions on the studies of the microconidia and for the use of his laboratory during the month of July, 
1920. 
3 According to the rules of nomenclature, the name Sclerotinia sclerotiorum (Lib.; Massee, is to be pre¬ 
ferred, but since the name S. libertiana Fckl. has been used exclusively in American literature, it seems 
best to carry this name in the present paper in order to avoid confusion (81). 
4 Reference is made by number (italic) to “ Literature cited,” p. 631. 
Journal of Agricultural Research, Vol. XXXI, No. 7 
Washington, D. C. Oct. 1,1925 
Key No. G-482 
71486—26f-1 
( 597 ) 
