, 1858-09-24
AgfieQIiuts.


Whatever Of theory or opinion men may
have of the cause of the curl of the peach
leaf all are united on one point, that its ef
fects are the almost entire destruction of the
peach crop upon nearly all the trees on which
it occurs so that if remedy or preventive
can be applied successfully, it ought to be
made known as Immediately as possible, as
the peach crop is rapidly becoming one of
the most important in the State.
We have received several communications
on the subject Of the peach leaf curl 4; in
some Of these, theories are advanced to &C.
count for the disease; in others, simply a
description of its effects upon the leaf
and fiui:; but all asking for a remedy or
preventive. =
We have made the subject of the curl of
tho peach leaf study for years. We have
examined it under every variety Of circum-
stances of soil, climate, heat, cold, IN every
phase, we believe, in which it is possible for
it to show itself, not only with view of
discovering the cause, but If possible pre-
ventive.
As our correspondent lone" remarks,
it appears in large orchard to 60 just where
it chooses, and nowhere else, sometimes is
streaks, now leaving a tree, and then taking
the next; or 1t will single out one, whilst
all around it escape" We eau even 60
further than this, by asserting that we have
known instances in which one half Of tree
would have the curl, whilst the other half
was entirely exempt; nor does exposure
either to or from the direct rays Of the sun
seem to govern its movements in the least.
The cause Of the blight is what we would
like to discover; for until it is found it is
useless to attempt or propose q remedy.
We do not think it is necessarily tho effect
Of frost upon the young leaves--though it
may seem to produce it in some instances
because the curl frequently appears in 10.
calities where no frost occurred. That it is
the work Of a minute microscopic insect,
singing the leaf and poisoning the sap, and
thereby producing morbid growth, we do
not believe neither can we attribute it to
the effect Of the worm at the root, nor yet to
fungi or minute vegetable parasites floating
in the air and aflixing themselves upon
the leaf and producing the effect we see,
until the leaf no longer able to sustain itself,
drops as from direct disease.
We believe it to be no disease of the tree
beyond the leaf ITSELF The peach tree is
subject to diseases. and among the worst is
the yeilOVs; but tho yellows as a disease is
easily disseminated, and always is, when
budding is done from diseased tree to
healthy one. Not so with the curl; we
have repeatedly tried the experiment by bud
ding from curl leaf tree to healthy one,
and by displacing portions of a healthy tree,
and supplying its place with bark from curl
leaf tree; but in no instance, or by any treat
ment possible, could the curl leaf be dissemin.
ated OF conveyed to one free from it. We
therefore place the seat Of the origin Of the dis
ease just where the disease appears, in the leaf
itself, and nowhere else. Consequently we
do notgo beyond the leaf, or direct influences
upon 1t, for the cause Of the disease.
No exposure, no situation, no apparent out.
ward condition Of the tree, is necessary to
induce the existence of the evil. It comes
where it will, and when it will. This leaves
usto believe that we should look to the effects
of climate, or heat and cold upon the leaf or
ganization. Leaves are the lungs of trees /;
as such they are like those of animals, or
gans Of delicate mechanism, and able to dis
organization, oftentimes from apparently
trivial causes. Thus all sudden changes from
heat to cold would be quite likely to affect
injuriously their delicate mechanism, made
more sensitive by the artificial condition Of
Fheir culture and growth; the use Of slim.