e distance around the tree or vertically it
dies shortly thereafter, but where only a small amount of splitting
occurs, the tree may recover if given attention. In such cases the bark
should be cut back to the living tissue and all particles of dead or
injured bark scraped off. The exposed area should then be coated with a
good tree paint or asphaltic emulsion.

The severest case of bark splitting observed was on a vigorous young
heartnut seedling at Guelph, Ontario. On this tree the bark was
completely split away entirely around the trunk from the ground up for
several feet and the injury was so great that the tree died early in the
summer. Within a short distance of this tree was another tree of the
same origin that was quite uninjured, but this tree, however, was a
hybrid between the butternut and the heartnut. On this hardy tree there
was a heavy crop of nuts that were intermediate in form between the
heartnut and the butternut, this indicating its hybrid origin.
Practically all of these hybrids escaped injury even though the
temperature was -30 degrees F.

Bark injury was also noticed at the Kellogg Farm on several black walnut
trees that had been grafted in the nursery and which were planted in
1932 and 1933. On these trees the scion variety was uninjured but the
bark on the stock was more or less affected from the ground up to the
point of union. All trees thus affected came out into leaf, but shortly
afterward the leaves withered and the top died.

Bark injury from splitting or desiccation was more prevalent on young
vigorous growing trees, and on older trees that had been stimulated into
a strong growth by fertilizers or late cultivation.

_Suggested Means of Control_

Since it is impossible to control temperatures and precipitation, it is
perhaps a vain hope to expect complete immunity from winter injury to
the English walnut. It is possible, however, to lessen the degree of
injury by certain measures of precaution. These are as follows:

(1) Plant only the hardiest varieties.

The past winter showed very clearly that the commercial varieties of
English walnut or seedlings as grown in this state are not hardy enough
to endure the severe cold that periodically occurs in Michigan. This
limits the choice of varieties to those from central Europe or north
China where rigorous climatic conditions prevail. As already pointed
out, the varieties that endured the past winter were from the Carpathian
region in