Belmont chronicle. [volume] (St. Clairsville, Ohio) 1855-1973, 1873-10-30
HORTICULTURAL MATTERS.
Report of the Committee of the
American POmological So
ciety en- Pear Blight.

Pear blight assumes different form:
, and has consequently different cause;
for its origin. One form attacks trees
: grdduatly; its approach is slow and
may be detected for months, and often
during the preceding season Of growth
before the tree is truly affected. This
!. form, which may be termed gradual
blight, is seen at ali seasons during the
period of active vegetation, from early
Spring until September. Its progress
is usually arrested by n liberal top,
dressing of liquid manure, so far as the
roots extend, and a severe cutting
back of the branches This mast be
done whenever the tree assumes an un.
healthy appearance. The cause, then,
may be safely attributed to exhaustion,
and the remedy consists in replenish-
ing the exhausted supply of plant food.
This form of blight is often noticed in
orchards l. it unworlyed and where the
annual or biennial top-dressing with
fertilizing agents has been withheld.
Another, and this is the most fatal
form, attacks a tree or portion of it
suddenly causing the affected part to
| .,lacken in few hours after the tree is
struck; this is commonly termed fire
blight. This form is periodical in its
attacks and migratory, as it seldom
remains permanent in locality, bat
! leaves an interval OF from ten to fifteen
years between its occurrence. Its
greatest intensity is on its first appear
ance, which occurs usually when the
fruit has attained half its size; it de-
creasas as the season OF vegetation adj
vances, but re-appears again the fol-
lowing summer with less of its previ-
Gus intensity. After decimating sec
tion of country during two consecutive
seasons. there will be an interval of
series of years, during which, blight in
| its other forms may occur, but there
will not be wholesale destruction as
during the prevalence of epidemic
blight. Every observation tends to
the conclusion that fire blight is caused
by zymotic fungus, whose presence is
not detected until life is destroyed in
the affected parts. This FORM offers a
wide field for the investigation OF mi
croscropists, ard from their future la
bors wc hope to arrive one day at the
origin of this fungoid growth. We are
unable TO arrive at satisfactory con-
ieIusion as 10 what peculiaritie5 of soil
induce the favorable conditions for
the development # this fungoid
vegetation.
In the experimental gardens of the
Department of Agriculture ut Wash
ington, the follow ing mixture is pre-
pared: Place half-bushel of lime
and six pounds of sulphur in a close
vessel, Xour over it about six gallons
of boiling water, adding enough cold
water to keep it in a semi-1uid State
until cold. 1t is used as wash and
applied to the trees and brlnces as high
as can be reached, 1t should be appli-
ed tive or three times during the Sum-
NOR. Since this preparation was used,
no trees thus treated have been lost,
although small limbs not coated with
the mixture were attacked and de-
stroyed. Carbolic acid has also been
used without any perceptible difference
in the result from 4he lime and sulphur
mixture. Boiled linseed oil applied TO
the trunk and limbs has been tried
near Norfolk, Va, with marvellous
cures, as reported. We mention this
instance of the use of an extraordinary
ingredient resulting in good effects, as
contrary to what is usually the result
when using this application upon the
body Of trees, its effects being to seri-
ously injure the tree, if it does not
destroy it.
Still another form Of blight is doubt
less caused by mechanical action. by
the rupture Of tissues consequent to 4
sudden superabundant flow of sap
This attacks only our most thrifty
growing trees, either in early Spring,
when veSetation first becomes active,
or after Il period of drought and partial
stagnation of vegetation, when abun-
dant rains suddenly force out luxu-
rant growth; moderately vigorous
trees are never attacked. 1t is often
noticed in very vigorous trees that the
trunk is split longitudinally; whenev-
er this is apparent, such trees are al
ways free from this form of blight, as
the pressure upon the cellular and vas
cular tissues has been relieved. From
series of experiments commenced in
1857, it is demonstrated that trees
whose bark has been longitudinally in
cised and divided never showed any
signs Of this form of blight.
Peculiar methods ofculture undoubt-
edly influence the causes of blight; but
upon this there exists a wide range of
opinian. Clean culture and repeated
stirring Of the soil, while it may in
many instances be coudusivo 10 most
beneficial results, will often cause Il
total destruction of a pear orchard. In
seasons of zymotic fungoid or fire
blight, highly cultivated trees fall ear
/ ly victims to the scourge, while those
4 cultivated in grass with an annual top
dressing of manure usually escape the
contagion.
The third form of blight caused by
mechanical action is seldom found in
orchards where the soil is left undis-