The trees have not reacted to the injections this year as quickly as
last summer. The slowness of reaction may be due to the season of the
year, the cool weather, and the large amount of rain since injections
began. As was to be expected, the trees have reacted to the injections
differently. Potassium chromate and bi-chromate caused the fastest and
most severe reactions. Reactions of the trees to the chemicals are
generally shown by discoloring, drying, or falling leaves. Sometimes
the trunk shows the path the solution followed by sunken areas, or long
cracks in the bark, extending up the tree. So far no results can be
given as to the effect of this year’s injections, either on the trees
themselves or on the canker growth. The full effect of the present
injections probably cannot be seen until next year.