. In 1952, the shedding of pollen started on April 29.
From the foregoing, it may be noted that the McKinster Persian is
entirely or largely self-pollinating. No other Persian walnut trees
which might assist in pollination occur in the vicinity and all known
seedlings raised from nuts of the parent McKinster tree have appeared to
be pure Persian. Leafing out starts about a week before the bloom
appears. In the fall, leaves are colored a beautiful bronze and are
brought down in a great shower by the first frost.

A sample of the soil in which the McKinster tree is growing, taken at a
depth of 6 inches, was tested in July 1950. The results specify that the
soil is mostly silt with an average amount of organic matter and that
evidence indicates it to contain ashes. The acidity is specified as
"neutral", potash "high", and phosphate "low". No mention is made of
available nitrogen; however, the dark green color of the leaves and
vigorousness of growth would indicate a satisfactory supply. Fertilizer
in small amount was applied once or twice during the early life of the
tree; also, during this period, Mr. McKinster "spaded in" garbage, etc.,
to increase the humus content of the soil. In 1951, the narrator checked
the pH of the soil near the surface and obtained a value of 6.5.

Only one instance of damage due to climatic conditions and none
whatsoever from insects and diseases has ever been observed with the
parent McKinster tree. Undoubtedly, the city location offers some
protection from frost, but may also be detrimental, on occasion, through
heat reflected from the many surrounding white-painted buildings. For
example, an unseasonable warm spell occurred in Columbus during the
latter part of the first week in April of the current year. The heat,
lasting for several days, reached a high of 80.4 degrees and, as a
result, the McKinster tree started vegetating. Leaf growths of from
one-half to one inch had been reached when normal conditions returned.
Two weeks later, a cold spell with snow and temperatures of 22 degrees
killed the new growth but did not injure the wood. Following this,
leafing re-occurred, but at a slower rate and somewhat later than
normal. The size ultimately attained by the leaves is about one-half
their usual size, and, consequently, the accompanying illustration,
taken this summer, does not exhibit the usual luxuriant appearance of
the tree. A large part of the bloom was damaged by the cold, hence the
t