Evening Republican, Volume 21, Number 31, Rensselaer, Jasper County, 7 February 1917 — Breeding Chestnuts for Disease Control [ARTICLE]

Breeding Chestnuts for Disease Control

How to checkmate the npw cheatnut blight or bark disease that is causing such vast destruction is a problem of no small importance. From its obscure beginnings In Eastern New York about twelve years ago, it has swept into nineteen States, and fiOBT affects about all of the northerlT half of our native chestnut stands, doing damage estimated at close upon SSO/000,000. It attacks the trees in twig, branch and trank, causing death in.ft.year or two, «nd. soon recurs far the sprouts or suckers sent up from tMy> still living roots. » No native appears to be spared in the long run, but the little Eastern'bush chinquapin, with its smoother bark and comparative freedom from insect enemies, appears less readily attacked. The European chestnut' In Its favorite varieties, is also subject to the disease, but when we come to the cjiefetnuts of Japan and China we fijid very great resistance, amounting In Rome varieties to almost practical immunity. There appears to be now no method of controlling this disease, witch is caused by a fungus whose spares are carried about by birds and ihstets, creating new infections whereever they reach the sap wood or inner, bark- of the chestnut tree. There is no apparent diminution of its virulence since it came under observation. The most obvious means of replacing the great losses of chestnut timber and nuts would seem to lie in the substitution for our native forms the Asiatic species that best resist the disease, having evidently for ages been accustomed to its presence, and atfiolo breed the chestnut as a val-

uable genus of forest trees, by hybridization and selection for the avowed pioduction of varieties better adapted fo* Our purposes. Some chestnut breeding ha£ already been accomplished hat various parts of our country, and generally vith good results. A promising experiment of this character has been under the direction of the Office of Forest Pathology of the U. S. Department of Agriculture for several years. Hybrids between the highly resistant Japan chestnut and our native chinquapin have been raised in con-* siderable numbers, quickly_ forming handsome dwarf trees, bearing at an early, age . profuse crops Of nuts of exrftlient. quality, flv& or slx -times, the.siib of those of the wild chinquapin pa.ent, and ripening weeks before any other chestnuts. So far these trees show a very high degree of disease resistance. The second generation bmybrids, grown from sen or chance pollinated nuts, appear quite aB good as their parents, which is an important feature when the cost of propagation of nut trees by budding and grafting is considered. . Another tire of breeding lies in the intercrossing of dißease-reslsting Japan and Chinese varieties that are rapidly being imported into this country by the Office of Foreign Seed and Plant Introduction, and selection of the best resulting forms. Four generations of cross-bred Japan chestnuts of a very early-bearing type, producing nuts when two or three years old, have already been grown, and the varietal 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 rbp^tnntßtahas.auMiierhahß~deTelop very superior varieties during the process of acclimatization. The hybrid chinquapins and crossbred chestnuts referred to in this article are not yet available for distribution to the public for testing, since they are being held for further observations as to their varietal characters and the degree of disease resistance.