Evening star. [volume] (Washington, D.C.) 1854-1972, 1897-08-14
CULTURE OF VEGETABLES
Bulletin Of Interest Just Issued by the De
partment Of Agriculture.
Results Of Experiments for Eradica-
The Methods Employed.

bulletin has just been issued by the
United States Department of Agriculture
which is of Interest to any one who has
gardening o. the raising of seeds and vege-
tables at cart. The bulletin tells of a
number of experiments of treating seeds
with carbon bisulphid for the purpose of
preventing the ravages of insects on grain
and seeds. TIE experiments were to de-
termine whether the vitality of the seed
was affected by the treatment and how
greatly. The report is as follows:
1.-The ravages of weevils and other in
sects in seed grain are well known to every
farmer. and are the cause of very serious
loss in the value of the seed, both for SOW
ing and food purposes. In some of the
southern states, especially, are such raw
ages SO severe that it Is often difficult to
get sound seed for sewing. The cowpea.
corn. wheat, rice and garden and field peas
are the main subjects of attack, but even
vegetable seeds are not exempt.
Seeds of the common pea are frequent
ly badly infested with weevils even when
grown as far north as Canada. Some seeds
men claim that such insects never injure
the embryo, hence do not lessen the SOW
ing value of the seed. This however, is a
serious error, for not only is the embryo
frequently injured, sometimes even de-
stroyed. but large amount of reserve ma
terial is consumed. the loss of which great
ly weakens the vitality of the young seed
lings.
The Methods Recommended.
1.-The common remedy advised by entomol-
ogists for destroying seed(infesting insects
is to treat the seed for twenty-four hours
with the fumes of carbon bisulphid at the
rate of one pound to the hundred bushels.
This chemical when pure is a colorless
liquid with pleasant odor. Upon expo
sure to the air the carbon and sulphur
composing the liquid are separated. each
uniting with oxygen, for which they have
a stronger affinity than for each other
Thus are formed carbon oxid and sulphur
dioxid. the latter being a very poisonous
gas with diSagreeable odor.
"The statement is made that seed grain
may be exposed to these fumes for thirty
six hours without injuring its terminating
capacity So far as we are aware no ex-
tended experiments have heretofore been
made to test the truth of this statement,
which. however. is generally accepted, and
which has very important bearings. For If
the treatment recommended is detrimental
to the terminating power of the seed, one
seed, but, what is far more serious, wouli
be subjected to delay In waiting for 1t 20
come up, and then be under the necessity
Of resolving.
FumigatfOn Sometimes Necessary.
I'm addition to treating seed to kill in
sects it is sometimes desirable, as in the
case of cotton, for instance, to fumigate
imported seed to avoid any risk of the in
PRODUCTION of disease germs. Carbon bisul-
rhid is also used for this purpose, and it is
exceedingly important to know whether
| the fumigating process is likely to injure
the vitality of such seed.
seeds are protected from external in
jury by a skin or coat which is thicker and
more impermeable in some kinds than in
others. Further protection is afforded to
| some species by the fact that their embryo
or germ Is surrounded by a firm mass Of
food material composed of starch and va
rious proteid or oily substances. Some
| times this material is deposited wholly in
the thickened seed leaves or cotyledons,
as in the case of the pea. On the. other
| hand. the embryo or 'chit" of corn, rye,
wheat, barley and other grains lies upon
| the surface just below the coat. Such
seeds are more susceptible to injury. Ow-
ing to these differences it Is necessary to
test the effect Of the carbon bisulphid upon
each of the kinds which for any reason
require treatment.
1.-THE length of time seeds must be treat
| ed with the fumes of carbon bisulphid de-
Ponds net only upon the resistant power of
the insect, but also upon its method Of at
tack. In the case Of the pea weevil the
larva is embedded within the immature
seed. becoming entirely surrounded by the
seed coat during its development, hence
| a treatment prolonged over twenty-four
weevi!s.
"Seedsmen treat peas and other buggy
| seeds on large scale by placing the bags
containing the seeds in a fireprcof, prac-
tically alright building devoted to that
purpose, setting shallow pans holding car
bon bisulphid in various parts Of the room
near the ceiling. After being thus subject
ed to the fumes for about twenty-four.
sometimes as long as forty-eight hours,
the room Is opened and thoroughly aired.
Some writer's have advocated pouring
the liquid through a pipe inserted into the
center of the bulk of seeds; others suggest
the use of q ball Of cotton, soaked with the
| chemical and plunged into the middle of
the pile of seeds. Both of these methods
are open to objection owing to the fact
that the liquid comes in direct contact
| with some Of the seed. which takes it up
readily. rendering such seed extremely liza
BILE to injury from the water which Is left
behind. II not from a superabundance Of
| the gas itself. Furthermore, carbon BIZ
| sulphid Is a very heavy gas. and the upper
stratum Of seeds treated In either Of these