The Bridgeport evening farmer., 1917-02-06
ASIATIC CHESTNUT
 WILL REPLACE THE AMERICAN SPECIE
Government Experts See Only Hope in Replacing Native Tree By Foreign Hybrids.

Washington, Feb. 6.-The possibi1- ity for continued growth of chestnut trees in the United States, in the face of the rapid spread of the destructive chestnut blight, may depend mainly upon replacing of the susceptible na- tive trees by disease-resistant strains and hybrids bred from Asiatic stock. This is pointed out by plant patholo- gists of the U. S. Department of Agri- culture who have made exhaustive studies of the disease in field and labo-
 ratory during the last five years. The chestnut blight, which is estimated to
 have caused already from sixty to one
 hundred millions of dollars damage in the eastern United States, and which is rapidly exterminating the American
 chestnut, came from eastern Asia on nursery stock The disease is com mon in both China and Japan, put in
 those countries causes relatively much less damage than in America. In both Asia and America the parasitic fungus causes cankers on chestnut bark, but
 in the American chestnut these cank- CTS soon completely girdle the tree, and invariably cause death. In Chi na and Japan, however, the trees com monly remain alive and productive for many years although cankered, the cankers seldom growing fast enough
 to girdle the trees.
 The specialties have identified seven
 species of the genus of fungi to which
 the organism causing chestnut blight
 belongs, five of which now exist in the
 United States. None of these causes
 disease, except the one which causes
 the chestnut blight. Fortunately, the
 f,-,o
 on trees other than the chestnut; du-
 ring their studies the specialists were
 able to find but four such specimens
 three of these were oaks, and one a
 maple Inoculation experiments in
 iicated that although the fungus can
 be made to grow on trees other than
 chestnut, it usually is but slightly
 parasitic in such cases and seldom in-
 jures the trees greatly.
 Tn their age-long struggle with the
 blight the Japanese and C nneseacnes
 nuts have acquired high degree of
 resistance to it, and this fact is being utilized by the specialists in breeding resistant chestnut trees for American k use Hybrids between the highly re-
 sistant Japanese chestnut and our na- tive chinquapin have been raised in considerable numbers. They quickly form handsome dwarf trees. bearing at an early age profuse crops of nuts of excellent quality, five or six times the size of those of the wild chinqua-
 pin parent, and ripening weeks be-
 fore any other chestnuts. So far
 these trees show a very high degree of
 disease resistance The second gen. eration of hybrids grown from self
 or chance pollinated nuts, appear quite as good as their parents, which is an important feature when the cost of propagation of fnut trees by bud- ding and grating is considered. An other line of breeding lies in the inter- crossing of disease-resisting Japanese and Chinese varieties that are rap idly being imported into this coun-
 try by the Office of Foreign Seed and
 Plant Introduction, and the selection
 of the best resulting forms. Four gen.
 erations of cross bred Japanese chest
 nuts of very early bearing. type, pro-
 ducing nuts when two or three years old, have already been grown, and the varieta1 characters appear to be well fixed. Some of the Chinese chestnuts are said to grow nearly 100 feet high in their home forests, and it may be possible by their use to replace in some measure our vanishing native chestnut stands, and perhaps develop superior varieties during the process of acclimatization.