ich he states that the butternut curculio did not
survive DDT powder.
In the past four or five years the butternut curculio (identified as
such by Prof. Conklin of the University of N. H.) has all but ruined my
Crath Persian walnuts and heartnuts, so, acting on the basis of Mr.
Graham's experiment, I had my trees dusted early in the morning when the
dew was on the leaves, using a 10% DDT powder, the first time about May
30 and again two weeks later, and I am happy to say that this dusting
has been very effective. I have been unable to find any sign of curculio
injury this year, although I have seen it nearby on some native
butternut trees.
My Gellatly heartnut was riddled by the curculio last year. This year,
when the dusting was done, this tree was overlooked, so I undertook to
dust it myself, and not realizing that the Niagara duster which I used
was set in the closed position, I dusted the tree with considerable
effort. In spite of the small amount of dust that came out, it proved
sufficient to keep the curculios away or else to kill them so that there
is no sign of any damage at this writing.
Persian Walnuts
In the spring of 1938 I planted a number of Crath Persian walnut
seedlings. Out of possibly eight or ten, only two survive. (I gave each
one about three years, and if it showed serious winter injury, I pulled
it up.) I was pleasantly surprised the other day to discover that one of
them has borne a single nut this year. This particular tree is at least
300' from any other Persian walnut, so it looks as if it were
self-fertile. It now remains to be seen whether or not the nut will
ripen.
In the spring of 1940, I planted a Broadview Persian walnut graft on
black walnut stock, and this tree is bearing for the first time with
eighteen nuts showing. Three or four years ago this Broadview suffered
some winter damage by a split trunk and split lower branch. I painted
over the cracks with gasket cement, and they are now healed. The
Broadview has also shown some winter-kill of terminal twigs, but not
enough to affect its bearing this year. There has been no splitting of
the trunks or branches of the two surviving Crath Persian walnut trees
and no winter injury to terminal twigs. The Crath walnut trees are now
18" in circumference a foot from the ground and about 12 to 15' tall.
The Broadview on the black walnut stock has a circumference of 16" above
the graft and 15-1/4" below the graft, tending to show that
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