Evening star. [volume] (Washington, D.C.) 1854-1972, 1897-08-14
ways is likely to receive too little Of the
fumes to destroy the insects.
The Varieties Trcated.


Our experiments were made with thirty
three different varieties of grains and vege-
tables. five of cotton, two of peas, three of
Indian corn, two of rice, two of Kaffir
corn, two of barley, two of wheat, one of
oats, etc. In all the experiments only
sound seeds were taken, being so far as
possible from single stock in each case
Two lots of treated seeds, each containing
800 seeds of the larger species and 100 of
the smaller kinds, were used. Similar lots
of untreated seeds were employed as
checks
I'm the first series of experiments the
seeds were placed in shallow glass vessels.
resting on plate of ground glass, covered
with bell jar containing a saturated at
mosphere of carbon bisulphid. At the end
of forty-eight hours the seeds were trans
ferred to the terminating chamber. in
which were placed also the check lots of
untreated seed.
this severe test, the terminating percent
ages Of both treated and untrcated seed
being practically the same: Peas, cotton,
beans, kaffir corn, buckwheat, turnip. cab
bage, caulifiower. pumpkin, cowpea and
oats. 1t is safe, therefore, to conclude that
none of the ordinary methods of treating
these seeds with carbon bisulphid will i'm
pair their vitality.
Germinntive Power Diminished.
ION the other hand, the germinattve ahil-
ity was decreased in barley. rye, wheat,
corn, crimson clover, millet and rice, the
difference between the treated and I'M
treated seed varying from So per cent in
the case of rye to per cent in the chalky
rice. With the exception of crimson clover,
whose seed Is much more tender than that
Of other ciovers, all of the injured kinds
belong to the grass family, oats alone of
this group showing no injury. This re-
sistant character of the oats Is easily ex-
planned from the nature Of its covering.
This method was an extreme one and
represents conditions which would probably
never be attained in actual practice. Here
each seed, being exposed to'a thoroughly
saturated atmosphere of the chemical, bad
ample opportunity to imbibe as much OF
the vapor 1t was capable of retaining.
1t is reasonable to suppose that Geeds
whose vitality was not affected by 49,
hour test of this kind would be in no dam
ger of deterioration in this respect from
any treatment given them in ordinary
practice.
1.-The varieties which were damaged by
the forty-eight hours treatment were then
subjected to another test of twenty-four
hours duration. Some of the varieties SUI
fered no deterioration whatever in vitality
with the twenty-four hours treatment.
while there was a marked decrease in the
amount Of injury in all of them.
Rye proved the most susceptible to in
Jury, with a difference of Al per cent be-
tween treated and untreated seed. Millet
showed us per cent, barley IL per cent,
and crimson clover 65 per cent difference.
All differences in termination tests amount
ing to per cent or less may be attributed
to variation in the quality of each lot of
seed used, and no conclusions should be
drawn from them with respect to the effect
of the treatment.
Treatment I'm Bulk.
'In order to ascertain whether similar
injury to the seeds named would re-
suit from treatment in bulk, one BUSH
ell each of wheat, rye, barley and
field corn were subjected to a second series
of experiments. One bushel Of each kind
Of grain was placed in an alright bin for
twenty-four hours. Upon the surface Of
the grain were shallow glass vessels con-
tanning carbon bisulphid in the proportion
of one pound to one hundred bushels, as
recommended by the division Of entomology
of this department. At the close of the
twentyfour hours lots OF each variety of
seed, both treated and untreated, were ger
minated in duplicate.
''It will be seen that no appreciate diff
ference in the vitality of wheat, corn, bar
ley or rye results from treating the seed
in bulk with carbon bisulphid for twenty
four hours at the rate of one pound Of the
chemical to one hundred bushels of the
grain.
I'm general seeds of cotton, peas. beans.
buckwheat, oats, the cabbage family, and
cowpeas. will endure the most severe treat
ment with the fumes of carbon bisulphii
without their termination being injured TO
any appreciable extent. On the other hand,
seeds OF corn, wheat, rye and other crops
belonging to the grass family Except Kafir
corn and oats) should be treated with eau
likely to result from excessive exposure
to the gas"