10 FARMERS’ 
been exposed to the blight for 25 
years or longer. Such reports 
should be addressed to the United 
States Agricultural Research Serv- 
BLIGHT-RESISTANT 
Asiatic chestnut species, although 
not immune to the blight, are 
highly resistant to it. They are re- 
sistant to Phytophthora root rot, 
also. Therefore, many seeds and 
scions of Asiatic chestnut spe- 
cies have been brought into the 
United States. These have been 
tested to determine whether the 
Asiatic species are suitable for 
extensive planting in this country. 
In Asia there are 3 principal spe- 
cies of chestnut and 1 of chinkapin: 
The Chinese chestnut, the Japanese 
chestnut, the Seguin chestnut, and 
the Henry chinkapin. 
The Chinese chestnut is more re- 
sistant than any other chestnut spe- 
cies to the blight fungus. Its nuts 
(fig. 9, 4) are sweeter and finer tex- 
tured than those of the Japanese 
chestnut and usually are larger than 
those of the American chestnut 
(fig. 9, B). The Chinese chestnut 
is the hardiest of the Asiatic chest- 
nuts. Its natural range, extending 
from south China, at elevations as 
great as 7,000 feet, north beyond 
Peiping, includes areas with very 
severe climate. In the northern 
part of its range the tree thrives 
only on the better sites, particularly 
lower mountain slopes where it has 
some protection, good air drainage, 
good soil, and the advantage of un- 
derground water from the slopes 
above. 
Chinese chestnuts growing vigor- 
ously on good sites in the United 
States have seldom been injured by 
the blight. However, when trees 
of this species are in an unthrifty 
condition, owing to poor site, 
drought, or winter injury, they are 
sometimes severely attacked and 
may even be killed by the blight 
fungus. 
BULLETIN 2068 
ice, Horticultural Crops Research 
Branch, Beltsville, Md., and the 
Connecticut Agricultural Experi- 
ment Station, New Haven, Conn. 
ASIATIC CHESTNUTS 
Many selections of Chinese chest- 
nut planted on favorable sites are 
growing well and producing good 
crops of nuts from southern New 
England to the Gulf States and 
from the Atlantic seaboard to just 
west of the Mississippi River. They 
have shown great differences in 
hardiness. In New York, for ex- 
ample, some of the trees have been 
damaged by a temperature of —20° 
F., but others have survived tem- 
peratures much lower than this 
without damage. The condition of 
the trees at the time of freezing, 
rather than the severity of the freez- 
ing temperature, is often the im- 
portant factor. Trees that are 
cultivated or fertilized in the fall 
may harden off slowly and be 
severely damaged by sudden freezes. 
Unusually low temperatures in late 
winter or early spring may kill 
trees, especially young ones. Late 
spring frosts may kill Chinese 
chestnut buds, some of which may 
contain undeveloped flower parts, 
or kill back the young shoots for 
some distance. Trees with bark 
and cambium killed by low tempera- 
tures may leaf out in the spring and 
then die a month or so later. In the 
meantime the chestnut blight fun- 
gus may develop in the bark of such 
clying trees. 
The Japanese chestnut grows wild 
in the mountains and hilly parts of 
Japan. The tree is not so tall as the 
American chestnut; the nuts range 
in size from that of the American to 
that of the European chestnut. 
Most Japanese selections have large 
nuts (fig. 9, @), but usually the 
kernels are coarse in texture and 
poor in flavor. 
Reports from Asia and prelimi- 
nary tests in this country indicate 
