10 Department Circular 370, U. S. Dept. of Agriculture 
What other valuable species can be used to reforest the land once 
occupied by the chestnuts? This is an important silvicultural prob- 
lem. The best means of bringing about the replacement of the chest- 
nut with other valuable species of trees is being studied by the 
Appalachian Forest Experiment Station at Asheville, N. C., in 
cooperation with various States. State and extension foresters are 
rendering assistance to private owners in planning for the utiliza- 
tion of their chestnut stands. ; 
BLIGHT-RESISTANT CHESTNUTS 
Since direct control of chestnut blight is impracticable, the dis- 
covery of suitable strains of chestnut resistant to the disease is highly 
desirable. Individual native chestnuts show differences in suscepti- 
bility to attack, but the number of trees actually surviving in regions 
where blight has been present longest is very small. Search for 
many years has disclosed only a few native specimens. Some of 
these trees are being propagated and further studied with the hope 
of developing a strain of American chestnut sufficiently resistant to 
attain maturity in the presence of the disease. It has been found 
that the numerous living trees which occur on tracts recently blight- 
killed are generally disease-escaping. rather than disease-resistant ; 
for this reason search for resistant specimens is profitable only on 
areas where all but very exceptional chestnut trees have been dead 
from the disease for a number of years. Reports of such resistant 
trees are desired. The Office of Forest Pathology records all such 
trees reported and inspects them as field work permits. 
A number of Japanese and Chinese species and strains of chestnut 
have been brought to this country in the hope of obtaining a tree 
which will thrive despite the chestnut blight. None of the trees so 
far imported and tested have proved immune, but the Japanese 
chestnut (Castanea japonica) and the hairy Chinese chestnut (C. 
mollissima) have considerable natural resistance. A number of these 
trees are known to have survived the blight, and reports of others 
are desired. Strains of these oriental chestnuts show marked differ- 
ences in susceptibility, and it is impracticable to control the blight 
on some of the very susceptible ones. However, most of the oriental 
trees can be saved by systematically cutting out any cankers which 
may appear and painting the wounds. Detailed information will be 
supplied by the Office of Forest Pathology to anyone interested in 
treating such trees. 
Most of the imported chestnuts so far tested have been suited for 
orchard culture rather than timber production. Other strains and 
additional species of Asiatic chestnut are being introduced by the 
Office of Foreign Seed and Plant Introduction of the Bureau of 
Plant Industry. There is reason to expect that ultimately among 
these introductions, resistant native strains, or crosses among these 
various forms, a tree will be found which possesses sufficient resist- 
ance to grow to timber size in the presence of the disease. 
