UNITED STATES DEPARTMENT OF AGRICULTURE 
Washington, D. C. 
PROFESSIONAL PAPER 
September 26, 1922 
KERNEL-SPOT OF THE PECAN AND ITS CAUSE. 
By J. B. Demabee, Assistant Pathologist, Office of Fruit-Disease Investigations, 
Bureau of Plant Industry. 
( OXTEXTS. 
Page. 
Distribution and history 1 
Economic importance 2 
Description of kernel-spot 3 
Present investigations 4 
Supplementary experiment 8 
Page. 
Laboratory cultures of kernel-spot- _ 8 
Analysis of results 11 
Control measures 11 
Summary 14 
Literature cited 15 
DISTRIBUTION AND HISTORY. 
The pecan kernel-spot is found throughout the southern pecan belt, 
including North Carolina, South Carolina, Georgia, Florida, Ala- 
bama. Mississippi, Louisiana, and Texas. This trouble is not evenly 
distributed over these States, but is more prevalent in restricted 
localities. Its appearance is more or less sporadic; that is, it may be 
abundant one season and almost absent the season following. 
The first published record of an investigation of pecan kernel-spot 
was in 1914 by Rand (-5). 1 As set forth in this preliminary account, 
the fungus C oniothyrium caryogenum Rand was isolated from affected 
pecan kernels. Rand reported that by subsequent inoculation in 
healthy kernels with this fungus he was able to produce in a series of 
laboratory experiments during 1912 and 1913 typical pecan kernel- 
spot symptoms. Laboratory inoculations with this fungus were so 
largely positive that it was considered by him to be the cause of the 
disease. 
Since Rand made no observations or investigations in the field in 
reference to pecan kernel-spot, he was unable to determine the time 
and manner in which the infection of his isolated fungus took place 
1 Serial numbers 
this bulletin. 
112351°— 22 
(italic) in parentheses refer to "Literature cited*' at the end of 
