The Republican journal., 1902-06-12
VEGETABLE 1MMUNES.
Inoculating Plants to Make Them Proof
Against Disease.

means OF hgntlng the numerous nlala-
dies which attack the garden, the
orchard and the ripening field crops.
Hypodermic injections of certain germ
cultures are given to the plants which,
being mildly sickened for awhile, pres
emily recover, and are thereafter proof
against nfectionAveritable vegetable
immunes, in fact.
1t would be out of the question,
obviously, for a farmer to 60 about in
fields and administer such medical
but, in truth, nothing of the kind is re-
quired. The object of the work is to
establish varieties that are immune,
and these may be counted upon to
transmit to their descendants the dis
ease-proof quality acquired 10y them.
! In a word, the tiller of the soil in future
years will cultivate only the immune
strains of vegetables, cereals and fruit
trees
Plants, like animals, are subject to
ever so many diseases, most of them
caused by germs of one kind or another.
Such micro-oIganlZSmS, when they
feed on the leaves, cause what are call
ed ''ruStS' and ''smuts.' which fire.
| quently do an immense amount of
damage. Often the fruit, in garden or
orchard, rotS in the very act OF rlpen-
ing. and this is as likely as not to be
occasioned by peculiar bacterium,
known to science as the bacillus putre-
faciens.
This bacillus has been chosen as a
special favorite for the incubation
work 1t grows rapidly on geIatine,
and is easily utilized, in a suitabl solu-
ton, for injection. Wheat, oats, beans,
suntioWers and radishes, when infected
in this way show symptoms of being
unwell, but soon throw them off. and
are henceforth proof, not only against
plant rot but also against other
common maladies due to germs.
The bacillus, in feeding on the gela-
tine, multlplies at a great rate, and i'll
cidentally develops poison peculiar to
itself. This poison, or toxin, as the eX-
perts call it, can be separated from the
germs themselves by a simple process
of iiltering. Then it may be used by
itself in making the injections: and, as
so far shown, it has the same effect in
rendering the plant immune. 1t ap-
pears to communicate the symptoms of
the complaint without the actual mala-
dy, but the result is equally satisfac-
tory.
|
that incubation is not really necessary
inasmuch as the same effects may be
secured by simply watering the plants
with the germ-culture, or with the toxin
derived therefrom. Such being the case
it might be easy for farmers to obtain
immunity for their crops by distribute
ing the remedy-or one should rather
say preventlVe-over their fields A
tubefull of bacterial culture once Sc
cured from a laboratory, or possibly
furnished by the government, there
would be no difficulty i'll making up the
preparation by the hogshead employing
"a dilute beef tea or other suitable solll-
tion of reasonable cheapness for the
propagation of the germs.
The loss occasioned to farmers in this
country annually by germ diseases
which attack the growing plants is gi-
gantic, and the prospect that such NAL
aides may be combated by preventive
inoculation naturally excites much
hopeful interest. Whereas some OF
these germs are bactaria. the great ma
jOrity of them are microscopic fungi
There are thousands of species of such
fungi. parasitic i'll habit, whose spores
corresponding TO seeds are always float
ing about in the air. Their depreda-
tions, when exceptionally severe, used
to be regarded as plaques sent by a dis
pleased Providence, but such matters
are better understood nowadays. and
our own department of agriculture has
made special study of means for fight
! ING the pests.
1t las also been discovered recently
that plants may be made more vigorous
, by watering them With oXygenated Wa
/ ter, and that they may be rendered
more resistent to disease 10y inOcuIating
them with apple acid OF grape acid
These acids are familiar commercial
products and easily obtained, though it
is not suggested that it would be worth
any farmers While to purchase them
for such purpose.
The study of germ disease of plants
occupies the entire attention of divi-
sion of the department of agriculture.
! Every now and then plague of one
kind or another breaks out in this re
gion or that, and experts are sent to
the locality to make study of it. Parts
of the afflicted plants are sent to Wash
! lngton, and the responsible fungi or
bactaria are propagated i'll glass tubes
he cultures thus obtained are used for
| inoculating healthy plants, and, if the
malady is reproduced, it is known that
the germ has been successfully ldenti-
fled. Then it remains to watch its life
history and to find out what will kill it
most quickly and surely.
Meanwhile cereals and other economic
plants are oss-bred for the purpose of
obtaining varieties that resist disease.
nt-breeding has been reduced to a
scientific basis, and the up to-date bot
anist is able literally to make almost
anything that he wants in the way of
vegetables, for example, by process of
artificial selection and suitable mating.
Where flowers combine both sexes, like
those of wheat or oats, he cuts away
the male part with pair of scissors,
fertillzes the blossom thus treated with
pollen from flower of another variety,
and ties it up in bag of paper or gauze,
to prevent any other pollen from get
ting at it. Thus he is able to marry
any two plants that are likely to pro-
duce improved otfsprings.
There are certain germs which, far
from being injurious to plants, are
highly beneficial to them. Peas and
beans, for example, depend largely for
their healthy growth upon bacteria
which attach themselves to the root
let's, feeding upon the latter and form
ing about each of their colonies a
woody tubercle. Thus the roots on
| which Snrh nirPo food arp