CHESTNUT TREE BLIGHT. 
DEPARTMENT OF AGRICULTURE, 
OFFICE or as SECRETARY, 
The PRESIDENT OF THE SENATE. Pn Crore One eP 
Sir: In accordance with the resolution of the Senate, under date 
of April 30, directing that the Secretary of Agriculture “submit to 
the Senate, at the earliest practicable day, the results thus far se- 
cured in the study and investigation of the so-called chestnut-tree 
blight, and the amount of money thus far expended in said study 
and investigation,” I have the honor to report as follows: 
Observations on the disease known as the chestnut-tree blight, 
or the chestnut-bark disease, were begun in this department in the 
summer of 1907, as soon as any office was Greanivel to do this class 
of work. The results secured in the study and investigation of this 
disease have been set forth in detail from time to time in the follow- 
ing publications, which are inclosed herewith, and constitute a part 
of this report: 
Bureau of Plant Industry Bulleti , i 
Chestnut to the Bark ieceee, ae 16, 1908." i ema A 
Forest Service, unnumbered circular: Extent and Importance of the Chestnut 
Bark Disease, October 21, 1908. 
Bureau of Plant Industry Bulletin No. 141, Part V, The Present Status of the Chest- 
nut Bark Disease, August 30, 1909. 
Farmers’ Bulletin No. 467, The Control of the Chestnut Bark Disease, October 28, 1911. 
A series of 34 photographs, mounted on 20 sheets, with explana- 
tory legends, illustrating various paces of the disease, are also 
appended, and constitute a part of this report. (Pls. I-X VI.) 
A summary of results follows: 
(1) The disease is caused by a parasitic fungus which kills the 
tree by girdling it at various points. Trees of all ages and condi- 
tions are afigead without discrimination. 
(2) A tree once attacked never recovers. It takes from two 
months to four years to kill a tree, according to the size of the tree 
and the point of attack. The average length of life of a diseased 
tree is three years. Trees killed by this disease sprout readily from 
the trunks and roots, but the sprouts are in turn infected and killed. 
(3) All species and varieties of chestnut now grown in this coun- 
try are abe to the disease, except the Japanese and Korean 
varieties, which are resistant. The Japanese and Korean chestnuts 
are small trees, fair nut producers, but probably valueless for tim- 
ber. No other species oe trees have as yet been parasitized by the 
fungus, but it is not impossible that other species, such as oaks and 
walnuts, may later become attacked. : 
(4) The disease is spread by the spores of the fungus, which are 
sticky in character. They are probably not diffused by wind to any 
appreciable extent, but are spread by rain, insects, probably also by 
birds, small mammals such as squirrels, and by man. Unbarked 
timber and cordwood from diseased trees aud diseased chestnut 
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