39 
FOREST PATHOLOGY 
By ARTHUR HARMOUNT GRAVES 
Chestnut Breeding Work in 1934 
For the benefit of those who are not acquainted with this work, 
it should be stated that the project consists of the interbreeding of 
various species and types of chestnut, with the object of replacing, 
if possible, with new stock, our valuable native chestnut trees. 
As is generally known, these have now practically disappeared 
from the forests of North America as the result of a deadly disease 
caused by the fungus, Fudothia parasitica. The progress of the 
work in previous years has been recounted in former volumes of 
the Brooklyn Botanic Garden Record (19: 62-67; 20: 83-87, 21: 
46-53; 22: 57-63; 23: 67-75). It was stated in last year’s report 
that ‘‘For the present our method is to cross-pollinate the blight- 
resistant Japanese chestnut, a [comparatively] low-growing, 
orchard type of tree, with the susceptible American timber tree, 
in the hope of getting, among the offspring of these two parents, 
the desired combination [of characters], that is, a blight-resistant 
tree of the tall timber type.”’ 
This plan has been considerably extended during the past year: 
we are now making crosses between as many species and hybrids 
as we can; and we are finding, incidentally, that the different 
forms are readily amenable to hybridization. It is scarcely 
necessary to add that in this way we shall obviously increase the 
— 
chances of ultimate success. Since the Garden plantations are 
too limited in area to include any considerable planting of chest- 
nut trees, the trial grounds for this work, covering several acres, 
are located on land belonging to the writer, a 40-acre plot on the 
southern slopes of Mt. Carmel (known locally as the ‘Sleeping 
Giant’’) in the township of Hamden, near New Haven, 
Connecticut. 
Blooming of [lybrids. By far the most important development 
of the past year was the blooming of three of our Japanese- 
American hybrids, which were only in their third year of growth. 
American chestnut seedlings (Castanea dentata) bloom ordinarily 
between the ages of 10 and 15 years, Japanese (C. crenata) 
sometimes as early as 5 years of age. ‘‘Blooming,”’ or the ap- 
