The Leon reporter. (Leon, Iowa) 1887-1930, 1901-06-13
FARM AND GARDEN.
MATTERS OF INTEREST TO
AGRlCULTURISTS
Some up-to-Dats Hints About Cultiya-
Sion Of tho Soil and Yields Thereof
Horticulture, yiticulturs and Floricnl-
tara.
New Light on Pear Blight.

New Light on Pear Blight
Pear blight has up to this time been
thing shrouded in good deal of
mystery. Efforts to check or eradicate
it have been so generally unsuccessful
that many growers of pears have come
to believe it an enemy too subtle to
be avoided. The real difficulty doubt
less has been our ignorance of its
methods of attack. The Delaware Ex-
peri ment Station has been doing some
good work along the line of finding out
just how the blight attacks the pears
and pear trees. The tests made con-
sisted in inoculating the pear tree in
its various parts with pure cultures OF
blight germs A sterilized needle was
dipped into culture and then used In
puncturing part on June 6, 1900, as
follows:
l.. Present years terminal shoots,
by puncture.
2. The previous years wood by
puncture.
8. Three years old wood by pune
ture.
4. Buds by puncture. y
8. Leaves by puncture. 4;D y
6. Fruit by puncture.
Z. Leaves smeared with broth Gull
keep off insects.
8. Leaves wet with distilled water,
and covered with paper bags (check).
8. Present years terminal shoots
smeared with broth culture, and COW
cred with bags.
The points of incubation in all
cases were covered with several layers
of wet filter-paper, and the papers tied
on with bands of wet cotton cloth.
We condense the notes OF results as
taken three weeks later: (D Twig
blighted. ca No result. 60 Only a
minute surface blighted around pune
ture. (4) Buds blighted. 60 One leaf
blighted over one-fourth of it's surface;
others showed only minute blight
spots. (6) Fruits blighted badly. CD
No result. (S) No blackening. (9) No
result
The preceding experiments show: i.
That pears become infected only by
direct incubation, and the introduce
ton of the virus, and that no infec-
ton results from contact of the germ
with an uninjured surface.
2. That only the more tender and
succulent parts become infected in this
manner, such as leaves, succulent
shoots, buds and fruit, and that older,
even second year wood, is not liable
to become infected even when injured
or punctured.
3. That the mechanical contact OF
blighted parts with those which are
healthy and uninfected is not likely
to result in infection.
Each independent member of the
| plant must therefore become separately
| infected in the manner indicated. The
germ may of course enter some tender
terminal growth and from this point
extend downward, often with cons1d-
cradle rapidity, so as to involve an
entire limb. But even here the in
Movement of an entire limb is more
likely TO imply the multiple infection
of terminal growthS attached to this
limb. The rate of the extension of
blight is much more rapid in the more
succulent than in the harder wood.
The disease appears to spread slowly
in older wood, sufficiently so at any
rate to give the fruitgrower time
enough to cut off the diseased term
inal shoots before the malady has ex-
tended downward to the large limbs.
The Control of Pear Blight.-In adj
dition to this early pruning it is i'm
portant to go through the orchard in
the fall, while the leaves are still ca
pable of showing the effects of blight,
and removing any blighted branches.
In cutting it is important to remove
the limb some inches below the line
of blight; the cut ends should then be
painted to prevent fresh infection.
There can be no doubt but that grow
ers fail to watch their trees closely
enough, and thus to check the disease
before it has done marked damage. A
primary factor in the control consists in
the pruning Of the blighted terminals,
before large limbs which have taken
years to form have been involved. The
best time to do this is several weeks
after blooming, since practically all the
infection of that year is likely to show
itself by that time, and it is quite i'm
probable that much new infection will
take place at later periods.