Chestnut Blight in the Southern Appalachians 5 
Their condition and location materially affect the rapidity wi 
which trees become infected. Those alte the edges Hy ne ei 
roads and isolated trees are not only more exposed to spores of the 
fungus but also have more mechanical injuries. Various mechanical 
os and the work of insects afford places of entry for the para- 
Lr 
SAE 
IW 
PER CENT OF INFECTED CHESTMWUT TREES PER COUNTY 
fHless tan/ W=/-2 Q=/o-2¢. [=3072 B=60-/00, 
—-— = Commercial Aange of Chestnut. 
Fie. 1.—Map showing the known distribution of chestnut blight in the southern Ap- 
palachians in March, 1926 
PRESENT DISTRIBUTION 
The distribution of the chestnut blight in the southern Appa- 
lachians is shown on a map (fig. 1), which presents the data from 
the incomplete survey of 1924 and 1925, supplemented by the re- 
ports of numerous cooperators. Table 1 briefly summarizes the 
survey of 1925. The degrees of infection which the table.and map 
show are based upon the average percentage of chestnut trees in- 
fected within a given county (fig. 1). The actual degree of infec- 
tion within a county varies greatly. For example, a county noted 
on the map as having an average of 50 per cent blight may contain 
tracts where the actual infection is less than 5 per cent and other 
tracts where the extent of the infection may be 95 per cent. 
