A field laboratory has all along been maintained at Charter Oak, and
much of the outdoor inoculation work and other experiments have been
conducted in that vicinity. Experiments have been conducted here on
the rate of growth of blight cankers, details of which are tabulated
in another manuscript, submitted for a bulletin. It is sufficient to
say here that the retarding influence of the winter season is shown by
these experiments. On the other hand, the cankers have continued to
spread even in the winter, though the growth is much more rapid in the
summer months.
Inoculations have been made both with ascospores and with pycnospores
during every month of the last year. No cankers have appeared as yet
from winter inoculations.
Other species of trees besides chestnut have been inoculated with the
blight fungus in larger numbers than last year, special attention
being given to the oaks. As yet there is no evidence that the blight
fungus will establish parasitic relation with any other host, although
occasionally a canker will be produced.
Careful tree surgery experiments have been conducted at Charter Oak,
and to date only three cases are reported in which the canker continued
to spread after cutting out and treatment.